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  • 1995-1999  (133)
  • 1985-1989
  • 1960-1964
  • 1935-1939
  • 1915-1919
  • 1890-1899
  • 1999  (133)
  • apoptosis  (112)
  • Biochemistry and Biotechnology
  • Genetics
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  • 1995-1999  (133)
  • 1985-1989
  • 1960-1964
  • 1935-1939
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  • 1
    ISSN: 1436-2813
    Keywords: thyroid tumor ; apoptosis ; TUNEL ; MIB-1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To clarify the growth mechanisms of thyroid tumors, we examined apoptotic cells in 61 thyroid tumors, consiting of 14 adenomas, 35 papillary carcinomas, 4 follicular carcinomas, and 8 undifferentiated carcinomas, using terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate digoxigenin-nick end labeling (TUNEL). The proliferative activity was also evaluated immunohistochemically using the monoclonal antibody to Ki-67 antigen (MIB-1) in the same tumors. The apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells, and a proliferation index (PI), being the percentage of Ki-67 positive cells, was calculated for each tumor. The overall level of AI was very low in all histotypes of the thyroid tumors analyzed, the mean AI being 0.5±0.4 in adenoma, 0.4±0.3 in differentiated carcinoma, and 1.8±1.5 in undifferentiated carcinoma. The PI in the thyroid tumor subtypes was significantly lower in adenoma and differentiated carcinoma, at 0.5 ±0.7 and 1.1±0.7, respectively, than that in undifferentiated carcinoma at 14.5±3.7 (P〈0.05). There was no correlation between clinicopathological factors and AI or PI in differentiated thyroid carcinoma. Our findings suggest that apoptosis occurs infrequently in thyroid tumors, and that proliferative activity markedly differs according to the thyroid tumor subtypes. Moreover, the ratio between proliferating cells and apoptotic cells may reflect thyroid tumor progression.
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  • 2
    ISSN: 1436-2813
    Keywords: Key Words: thyroid tumor ; apoptosis ; TUNEL ; MIB-1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: P 〈 0.05). There was no correlation between clinicopathological factors and AI or PI in differentiated thyroid carcinoma. Our findings suggest that apoptosis occurs infrequently in thyroid tumors, and that proliferative activity markedly differs according to the thyroid tumor subtypes. Moreover, the ratio between proliferating cells and apoptotic cells may reflect thyroid tumor progression.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neural transmission 106 (1999), S. 1-21 
    ISSN: 1435-1463
    Keywords: Keywords: Paraquat ; Parkinson's disease ; transcription factor ; AP-1 ; apoptosis ; cycloheximide ; genistein ; SOD ; catalase ; oxidative stress.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary. Drugs and certain environmental toxins may be responsible for the pathogenesis of Parkinson's disease. We have used paraquat as a model toxin for this study since paraquat has been shown to make its way to the nerve terminals and cause cell death of dopamine neurons by oxidative injury. We have shown by the electrophoretic mobility shift assay that paraquat, together with low concentrations of chelated iron (Fe++/DETAPAC), induced the activation of transcription factor AP-1 binding activity to DNA. Under similar conditions we also found by both a DNA laddering assay procedure and by terminal deoxynucleotidyl transferase assay (TUNEL assay) that paraquat also induces apoptotic cell death. Interestingly, both apoptotic cell death and AP-1/DNA binding activity induced by paraquat were blocked by cyclohexamide and genistein, indicating that both the AP-1/DNA binding activation and apoptosis induced by paraquat are closely related. Moreover, cells were also protected from paraquat toxicity in the presence of antioxidant defense enzymes SOD and catalase. The results support the hypothesis that oxidative stress may be contributing to the apoptotic cell death of dopaminergic neurons, leading to the manifestation of Parkinson's disease. Since paraquat was an important herbicide in the mid 20th Century, our results have the important implication that exposure to environmental toxins such as paraquat may induce Parkinson's disease.
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  • 4
    ISSN: 1364-6753
    Keywords: Key words Multiple sclerosis ; Genetics ; Myelin basic protein ; Myelin oligodendrocyte glycoprotein ; Proteolipid protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: ABSTRACT Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system. A complex genetic etiology is thought to underlie susceptibility to this disease. The present study was designed to analyze whether differences in genes that encode myelin proteins influence susceptibility to MS. We performed linkage analysis of MS to markers in chromosomal regions that include the genes encoding myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMGP), and myelin oligodendrocyte glycoprotein (MOG) in a well-characterized population of 65 multiplex MS families consisting of 399 total individuals, 169 affected with MS and 102 affected sibpairs. Physical mapping data permitted placement of MAG and PLP genes on the Genethon genetic map; all other genes were mapped on the Genethon genetic map by linkage analysis. For each gene, at least one marker within the gene and/or two tightly linked flanking markers were analyzed. Marker data analysis employed a combination of genetic trait model-dependent (parametric) and model-independent linkage methods. Results indicate that MAG, MBP, OMGP, and PLP genes do not have a significant genetic effect on susceptibility to MS in this population. As MOG resides within the MHC, a potential role of the MOG gene could not be excluded.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Italian journal of neurological sciences 20 (1999), S. 89-108 
    ISSN: 1126-5442
    Keywords: Key words Neurofibromatosis ; Nf1 ; Nf2 ; Mosaic/segmental neurofibromatosis ; Variants ; Classification ; Neurological manifestations ; Genetics ; Childhood ; Adulthood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The last two decades have seen clinical and molecular delineation of the different forms of neurofibromatosis. Differentiation of these forms is not just an academic exercise: their natural history, management and genetic counselling are quite different. Of the numerical classifications of neurofibromatosis proposed in the past, only neurofibromatosis type 1 (Nf1) and neurofibromatosis type 2 (Nf2) are now well delineated clinically and have been shown to be distinct at the molecular level. For both forms of neurofibromatosis, patients with clinical generalised disease have been demonstrated to be mosaic at the molecular level, and features of segmental or mosaic Nf1 and Nf2 have been delineated. Other reported forms of neurofibromatosis are rarer; they include Watson syndrome, hereditary spinal neurofibromatosis, familial intestinal neurofibromatosis, autosomal dominant café-au-lait spots alone, autosomal dominant neurofibromas alone, and schwannomatosis, the latter believed to be a variant of Nf2. Further delineation is neeeded for individuals having overlapping features of Noonan's syndrome and neurofibromatosis (the so-called Noonan/neurofibromatosis syndrome) and the syndrome of “multiple naevi, multiple schwannomas and multiple vaginal leiomyomas”. In this article we review the forms of neurofibromatosis which we believe are true clinical entities. Particular attention is given to the neurological manifestations of neurofibromatosis.
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  • 6
    ISSN: 1572-8773
    Keywords: cadmium ; apoptosis ; RT-PCR ; p53 gene expression ; testes ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Reverse transcription (RT) PCR technique was used to investigate the mechanism of apoptosis induced by Cd and the change of its related genes in testes and prostate of rats. Adult male rats were given a single (s.c.) injection of CdC l2 0, 2.5, 5.0, 10 μmol/kg. 48 h and 72 h after administration of Cd, animals were sacrificed. The results indicated that Cd can induce apoptosis in testes via p53-independent pathway. No apoptosis occurred in prostate in any of the Cd-exposed groups. There was a clearly negative relationship in testes between p53 gene expression and Cd exposure and this dose-response relationship was observed both at 48 h and 72 h. There was a very small increase of this gene expression in the dorsolateral lobe of the prostate in Cd exposed groups. The other apoptosis related gene, bcl-x, was not detectable in either control or Cd-exposed group in testes and dorsal prostate. Although the MT-I gene was expressed in testes or dorsal prostate both in control and exposed groups, no overexpression of MT-I gene was found after administration of Cd . The expression of MT-I in the ventral prostate was not detected in the control group, but a weak expression was found after Cd exposure. Since p53 is a tumo r suppressor gene which can inhibit tumorigenesis, the consequence of a Cd-induced decrease of p53 in testes may have a relation to the known risk of Cd tumorigenesis in this tissue.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1569-8041
    Keywords: AML ; apoptosis ; etoposide ; γ-GCS ; glutathione ; oxidative stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Etoposide mediates its cytotoxicity by inducing apoptosis. Thus, mechanisms which regulate apoptosis should also affect drug resistance. Oxidants and antioxidants have been shown to participate in the regulation of apoptosis. We were interested in studying whether responsiveness of acute myeloblastic leukemia (AML) cells to etoposide is mediated by oxidative stress and glutathione levels. Patients and methods: Two subclones of the OCI/AML-2 cell line which are etoposide-sensitive (ES), and etoposide-resistant (ER), were established by the authors at the University of Oulu, and used as models. Assays for apoptosis included externalization of phosphatidylserine (as evidenced by annexin V binding), and caspase activation as indicated by cleavage of poly(ADP-ribose)polymerase (Western blotting). Peroxide formation was analyzed by flow cytometry. Glutathione and gamma-glutamylcysteine synthetase (γ-GCS) levels were determined spectrophotometrically and by Western blotting, respectively. Results: Etoposide-induced apoptosis was evident 12 hours after treatment in the ES subclone, but was apparent in the ER subclone only after 24 hours. The basal glutathione and γ-GCS levels were higher in the ER than the ES subclone. Etoposide increased peroxide formation in both subclones after 12-hour exposure. Significant depletion of glutathione was observed in the ES subclone during etoposide exposure, while glutathione levels were maintained in the ER subclone. In neither of the subclones was induction of γ-GCS observed during 24-hour exposure to etoposide. Furthermore, the catalytic subunit of γ-GCS was cleaved during apoptosis, concurrent with depletion of intracellular glutathione. When glutathione was depleted by treatment with buthionine sulfoximine, a direct inhibitor of γ-GCS, the sensitivity to etoposide was increased, particularly in the ER subclone. Conclusions: The results underline the significance of glutathione biosynthesis in the responsiveness of AML cells to etoposide. The molecular mechanisms mediating glutathione depletion during etoposide exposure might include the cleavage of the catalytic subunit of γ-GCS.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Annals of oncology 10 (1999), S. 495-503 
    ISSN: 1569-8041
    Keywords: antisense ; apoptosis ; bcl-2 ; lymphoma ; leukaemia ; phase I
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Annals of oncology 10 (1999), S. 1011-1021 
    ISSN: 1569-8041
    Keywords: apoptosis ; chemosensitivity ; cytotoxicity ; p53
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Although hematologic malignancies and some solid tumors such as germ cell tumors and pediatric malignancies can be cured by cytotoxic treatment, the most prevalent solid tumors are relatively resistant to these interventions. Apoptosis is involved in the cell kill of anticancer drugs and p53 is believed to be of principal importance in this process. However p53 also plays a role in cell cycle arrest and DNA repair, cellular processes that can decrease the sensitivity to chemotherapy. Therefore, p53 may play a dual role after exposure to cytotoxic treatment, activating either mechanisms that lead to apoptosis or launching processes directing to DNA repair and survival of the cell. Design: In this article, we review in details the p53functions involved in the mediation of chemosensitivity. The preclinical and clinical data published in the recent years about the relation between p53 and chemosensitivity are discussed and the potential pitfalls associated to most of these studies, and that may account for the contradictory results produced so far are also mentioned.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Annals of oncology 10 (1999), S. 31-38 
    ISSN: 1569-8041
    Keywords: apoptosis ; lanreotide treatment ; neuroendocrine gastrointestinal tumors ; octreotide ; somatostatin analogs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neuroendocrine gastrointestinal tumors express somatostatin receptors (ssts) in 80%–90% of cases and somatostatin analogs have become increasingly important in the management of these patients. Most of the presently available somatostatin analogs (octreotide, RC-160, and lanreotide) bind to the sst2 and sst5, and in higher doses to sst3 of the ssts 1–5 described. Clinical improvement during somatostatin analog therapy is mainly mediated via a direct inhibitory effect on hormone production from the tumors, seen in 30%–70% of the patients. Also indirect non-tumor mediated effects on peripheral target organs contribute to the subjective improvement, achieved in 30%–70% of patients. Recently, significant improvement of quality of life has been demonstrated with long-acting depot formulations. There is little or no effect on tumor growth during octreotide therapy; tumor shrinkage has been reported in 10%–20% of patients, but stabilization of tumor growth can be achieved in about half of the patients with a duration of 8–16 months. Recently, induction of apoptosis has been described with high doses of lanreotide (12 mg/d). Eventually, however, all patients escape from somatostatin analog therapy with regard both to hormonal production and tumor growth, and the mechanism behind the tachyphylaxis is not yet known. Studies of optimal dosage and modes of administration, development of new slow release formulations, the potential value of high-dose somatostatin analog therapy and novel somatostatin receptor subtype specific analogs are important directions for the use of somatostatin analogs in the future. In addition, assessment of somatostatin receptor status for each patient and studies of tumor biology, e.g., inhibition of exocytosis, antiproliferative effects and induction of apoptosis during treatment will help to optimize treatment and provide new insights into mechanisms of action of somatostatin analogs.
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  • 11
    ISSN: 1432-1440
    Keywords: Key words Diabetes ; Genetics ; Phosphofructokinase ; Glycogenosis ; NIDDM ; PFK
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The etiology of non-insulin-dependent diabetes mellitus (NIDDM) is usually explained as a combination of peripheral insulin resistance and impaired beta-cell function. Phosphofructo-1-kinase (PFK1) is a rate limiting enzyme in glycolysis, and its muscle subtype (PFK1-M) deficiency leads to an autosomal recessively inherited disorder known as glycogenosis type VII or Tarui’s disease. It was evaluated whether PFK1-M deficiency leads to NIDDM in humans. A core family of four was evaluated for PFK1-M deficiency by DNA- and enzyme-activity-analyses. All members underwent oral and intravenous glucose tolerance test (oGTT/ivgtt), as well as an insulin sensitivity test (IST) using octreotide. Results: Father (46 years, BMI 22.4 kg/m2) and older son (19 years, BMI 17.8 kg/m5) showed homozygous PFK1-M deficiency, while mother (47 years, BMI 28.4 kg/m5) and younger son (13 years, BMI 16.5 kg/m5) were shown to be heterozygously PFK1-M-deficient on enzyme activity levels. DNA analysis revealed an exon 5-missense-mutation at one allele of all four members, and an exon 22-frameshift-mutation at the other allele of the two homozygously affected individuals. By oGTT the father showed impaired glucose tolerance, and the mother clinical diabetes. By ivGTT both parents and the older son had a decreased first phase insulin secretion, and a diminished glucose disappearance rate. The IST showed marked insulin resistance in both parents and the older son, and moderate resistance in the younger son, previously not described. Conclusion: PFK1-M-deficiency leads to a metabolic state typical for early NIDDM in homozygously affected humans, especially concerning insulin resistance and loss of first phase beta-cell insulin secretion, and may contribute to the manifestation of NIDDM in a subgroup of patients.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Der Nervenarzt 70 (1999), S. 195-205 
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Alzheimer-Krankheit ; Genetik ; Risikofaktoren ; Genetische Beratung ; Key words Alzheimer’s disease ; Genetics ; Risk factors ; Genetic counseling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A multifactorial etiology underlies the majority of cases of Alzheimer’s disease (AD). Both ill-defined environmental and genetic factors contribute to the development of the disease. Allele ɛ4 of ApoE is a genetic risk factor. Its presence increases the risk of developing AD. However, presence of e4 is neither necessary nor sufficient for the disease to arise. Apart from the common multifactorial forms of the disease, there are rare variants which are inherited as Mendelian traits. To date three genes are known that can be mutated in these rare forms of AD. Of these, mutations in the gene presenilin 1 on chromosome 14 are most frequent. In addition, mutations in the gene presenilin 2 on chromosome 1 and in the amyloid precursor protein gene (APP on chromosome 21) occur in autosomal dominant AD. This article reviews our present knowledge of the genetics of AD and discusses its relevance for patients with AD and their relatives.
    Notes: Zusammenfassung Der Großteil der Fälle von Alzheimer-Krankheit (AK) hat eine multifaktorielle Ätiologie. Das bedeutet, bisher nicht genauer bekannte Umwelteinflüsse und genetische Faktoren spielen bei der Entwicklung der Krankheit eine wesentliche Rolle. Von seiten der Genetik unterscheidet man bei der AK gegenwärtig genetische Risikofaktroren und Mutationen. Der einzige bisher gesicherte genetische Risikofaktor ist das Allel ɛ4 des Gens für Apolipoprotein E auf Chromosom 19. Dieses Allel erhöht die Wahrscheinlichkeit, an der AK zu erkranken, ist jedoch weder eine notwendige noch eine hinreichende Bedingung. Neben den häufigen Formen mit multifaktorieller Ätiologie kommen seltene Varianten der Krankheit vor, die nach Mendelschen Regeln vererbt werden. Bisher sind 3 Gene bekannt, die bei diesen seltenen, in der Regel früh auftretenden und autosomal dominant vererbten Formen mutiert sein können. Am häufigsten findet sich bei den autosomal-dominanten Fällen eine Mutation im Gen präsenilin 1 auf Chromosom 14, seltener liegen Mutationen im Gen präsenilin 2 auf Chromosom 1 und im Gen des Amyloid- Vorläuferproteins auf Chromosom 21 vor. In diesem Beitrag geben wir eine Übersicht über gegenwärtige Befunde zur Genetik der AK und diskutieren die Bedeutung dieses Wissens für Patienten und deren Verwandte.
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  • 13
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Schizophrenie ; Genetik ; Schizophrenes Spektrum ; Kopplungsuntersuchungen ; Assoziationsuntersuchungen ; Key words Schizophrenia ; Genetics ; Schizophrenia spectrum ; Linkage studies ; Association studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Schizophrenia is a genetic complex disease as it does not follow monogenic transmission while non-familial environmental factors have a strong additional impact. A heterogenous, continuous phenotype is transmitted in families which can now be more precisely characterized. Genes coding for proteins with presumed pathophysiological relevance are apparently not playing a major causal role. However, in the last three years several (currently seven) candidate regions have been identified in a replicable manner by linkage studies. These regions are likely to host susceptibility genes for schizophrenia, but none of them has been identified up to now. Given these findings, polygenic transmission has now become very likely. The candidate regions are currently being narrowed down by various promising techniques.
    Notes: Zusammenfassung Die Schizophrenie gehört zu den genetisch komplexen Erkrankungen, die keinem monogenen Erbgang folgen und bei denen auch nichtfamiliäre Umgebungsfaktoren eine wichtige Rolle spielen. Dabei wird intrafamiliär ein heterogener, quantitativ variierender Phänotyp übertragen, der zunehmend genauer charakterisiert werden kann. Keines der bekannten Gene mit vermuteter pathophysiologischer Relevanz spielt nach den bisherigen Erkenntnissen eine substantielle Rolle. In den vergangenen drei Jahren ist es aber erstmals durch Kopplungsuntersuchungen gelungen, mehrere replizierbare Kandidatenregionen (derzeit sieben) auf dem Genom zu identifizieren, in denen vermutlich Suszeptibilitätsgene für Schizophrenie liegen. Keines dieser Gene wurde jedoch bislang identifiziert. Mit diesen Befunden ist eine polygene Übertragung der Schizophrenie sehr wahrscheinlich geworden. Verschiedene Techniken zur Eingrenzung der Kandidatenregionen werden derzeit erfolgreich angewandt.
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  • 14
    ISSN: 1436-2813
    Keywords: Key Words: nitric oxide ; DNA damage ; apoptosis ; tumor necrosis factor-α ; mitochondrial respiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: S -nitroso-N-acetylpenicillamine protected cul-tured L929 cells from apoptosis induced by tumor necrosis factor-α (TNF-α) plus actinomycin D, as determined by the detection of DNA fragmentation and morphological changes. NO also prevented an enhancement of the production of reactive oxygen intermediates by TNF-α plus actinomycin D, as assessed by the oxidation of dihydrorhodamine 123 and hydroethidine. Because the inhibition of mitochondrial respiration by rotenone or antimycin A suppressed the increased oxidation of both dihydrorhodamine 123 and hydroethidine, it was suggested that TNF-α accelerated the leakage of reactive oxygen intermediates from the mitochondrial electron transport system. Polarography showed that NO reversibly inhibited mitochondrial respiration at either complexes I–III, II–III, or IV, thus suggesting the inhibition of cytochrome oxidase. Taken together, these findings indicate that the decreased mitochondrial formation of reactive oxygen intermediates in the presence of NO might have a protective effect against TNF-α plus actinomycin D-induced apoptosis.
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  • 15
    ISSN: 1436-2813
    Keywords: angiogenesis ; p53 ; apoptosis ; lung adenocarcinoma ; hematogenous metastasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this study was to clarify which factors are important as predictors not only of patient survival but also of hematogenic metastasis in 15 patients with stage I lung adenocarcinoma who underwent curative operation. The relationship between tumor angiogenesis, apoptosis, and p53 oncogene was also studied. A total of 15 patients were divided into two groups: surviving group (n=7) and nonsurviving (metastasis) group (n=8). We studied the medical charts, operative records, pathologic reports, and tumor specimens taken at surgical resection. We measured the apoptotic index using the ApopTag kit and the intratumoral microvessel count using an anti-CD34 monoclonal antibody. In addition, immunohistochemical staining for the expression of p53 was conducted simultaneously. The clinicopathological characteristics, including age, sex, tumor size (pT), and histological differentiation, were not significantly different between the surviving and the nonsurviving group. The microvessel count was significantly higher in nonsurviving group than in the surviving group. The apoptotic index and the expression of p53 was not significantly different between the two groups. An inverse correlation between the apoptotic index and microvessel count, and a positive correlation between the expression of p53 and microvessel count, were observed. Angiogenesis may be an important prognostic factor in patients with stage I lung adenocarcinoma.
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  • 16
    ISSN: 1436-2813
    Keywords: Key Words: angiogenesis ; p53 ; apoptosis ; lung adenocarcinoma ; hematogenous metastasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: n = 7) and nonsurviving (metastasis) group (n = 8). We studied the medical charts, operative records, pathologic reports, and tumor specimens taken at surgical resection. We measured the apoptotic index using the ApopTag kit and the intratumoral microvessel count using an anti-CD34 monoclonal antibody. In addition, immunohistochemical staining for the expression of p53 was conducted simultaneously. The clinicopathological characteristics, including age, sex, tumor size (pT), and histological differentiation, were not significantly different between the surviving and the nonsurviving group. The microvessel count was significantly higher in nonsurviving group than in the surviving group. The apoptotic index and the expression of p53 was not significantly different between the two groups. An inverse correlation between the apoptotic index and microvessel count, and a positive correlation between the expression of p53 and microvessel count, were observed. Angiogenesis may be an important prognostic factor in patients with stage I lung adenocarcinoma.
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  • 17
    ISSN: 1432-0533
    Keywords: Key words Frontotemporal dementia ; Genetics ; Progressive supranuclear palsy ; Tauopathy ; Exon ; amplifcation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recently intronic and exonic mutations in the Tau gene have been found to be associated with familial neurodegenerative syndromes characterized not only by a predominantly frontotemporal dementia but also by the presence of neurological signs consistent with the dysfunction of multiple subcortical neuronal circuitries. Among families, the symptomatology appears to vary in quality and severity in relation to the specific Tau gene mutation and often may include parkinsonism, supranuclear palsies, and/or myoclonus, in addition to dementia. We carried out molecular genetic and neuropathological studies on two patients from a French family presenting, early in their fifth decade, a cognitive impairment and supranuclear palsy followed by an akinetic rigid syndrome and dementia. The proband died severely demented 7 years after the onset of the symptoms; currently, his brother is still alive although his disease is progressing. In both patients, we found a Tau gene mutation in exon 10 at codon 279, resulting in an asparagine to lysine substitution (N279K). Neuropathologically, widespread neuronal and glial tau accumulation in the cortex, basal ganglia, brain stem nuclei as well as in the white matter were the hallmark of the disease. These deposits were shown by immunohistochemistry and immunoelectron microscopy, using a battery of antibodies to phosphorylation-dependent and phosphorylation-independent epitopes present in multiple tau regions. In the neocortex, tau-immunopositive glial cells were more numerous than immunopositive neurons; the deeper cortical layers as well as the white matter adjacent to the cortex contained the largest amount of immunolabeled glial cells. In contrast, some brain stem nuclei contained more neurons with tau deposits than immunolabeled glial cells. The correlation of clinical, neuropathological and molecular genetic findings emphasize the phenotypic heterogeneitiy of diseases caused by Tau gene mutations. Furthermore, to test the effect of the N279K mutation and compare it with the effect of the P301L exon 10 mutation on alternative splicing of Tau exon 10, we used an exon amplification assay. Our results suggest that the N279K mutation affects splicing similar to the intronic mutations, allowing exon 10 to be incorporated more frequently in the Tau transcript.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Annals of hematology 78 (1999), S. 485-494 
    ISSN: 1432-0584
    Keywords: Key words Mantle cell lymphoma ; Classification ; Pathology ; Prognosis ; Immunology ; Genetics ; Antineoplastic agents ; Combined ; Therapeutic use ; Radiotherapy ; Hematopoietic stem cell transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 19
    ISSN: 1432-0584
    Keywords: Key words Acute leukemia ; Genetics ; Sex ; ABO Blood group
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Acute leukemia is more common in males at almost every age, and this fact remains unexplained. A study was carried out in northeast peninsular Malaysia, where the population is predominantly Malay, to examine whether there was a difference in ABO blood group distribution between males and females with acute leukemia (AL). The ABO blood groups of 109 male and 79 female patients with AL (98 ALL, 90 AML) were compared with those of 1019 controls. In the control population, 39.7% were group O. Among males with AL, 39.4% were group O, whereas among females with AL, the proportion was 24.1% (p=0.03). The same trend to a lower proportion of group O among females was seen if the group was divided into adult/pediatric or lymphoblastic/myeloblastic groups, though these differences were not statistically significant. If these findings can be confirmed, they suggest the presence of a "sex-responsive" gene near to the ABO gene locus on chromosome 9, which relatively protects group O women against AL, at least in our population. The existence of such a gene might also partly explain why acute leukemia, and possibly other childhood cancers, are more common in males.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 42 (1999), S. 711-718 
    ISSN: 1432-0428
    Keywords: Keywords Malnutrition ; ageing ; beta-cell mass ; apoptosis ; glucose tolerance.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Aims/hypothesis. In a recently developed rat model, maternal food restriction from day 15 of pregnancy until weaning induced low birth weight and a 70 % reduction of beta-cell mass in the offspring at day 21 after birth. Subsequent renutrition from weaning was insufficient to fully restore beta-cell mass in young adult rats. The aim of this study is to investigate the long-term consequences of early malnutrition on beta-cell mass and function. Methods. Oral glucose tolerance tests were done in 3- and 12-month-old animals and beta-cell mass and apoptosis were determined by morphometrical measurements on pancreatic sections. The specific impact of postnatal malnutrition was studied by comparing control animals (C group) with animals malnourished during their fetal life only (R/C group), and animals malnourished during fetal life and until weaning (R group). Results. In 3-month-old R/C animals beta-cell mass reached 8.0 ± 1.5 mg with no further increase until 12 months (8.1 ± 1.5 mg), compared with 9.3 ± 1.9 mg in control rats. Twelve-month-old R/C animals showed normal plasma insulin responses and borderline glucose tolerance. In R animals, apoptosis reached 1.9 ± 0.4 % of the beta cells at 3 months, compared with 0.7 ± 0.5 % in control rats, and beta-cell mass did not increase between 3 and 12 months (4.7 ± 0.8 mg at 12 months). In aged control and R animals, apoptosis affected 8 % of the beta cells. At 12 months only, R animals showed profound insulinopenia and marked glucose intolerance. Conclusion/interpretation. In conclusion, perinatal malnutrition profoundly impairs the programming of beta-cell development. In animals with decreased beta-cell mass the additional demand placed by ageing on the beta cells entails glucose intolerance since beta-cell mass does not expand and apoptosis is increased. [Diabetologia (1999) 42: 711–718]
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  • 21
    ISSN: 1432-0428
    Keywords: Keywords Type I diabetes ; interferon-γ ; transgenic mice ; apoptosis ; insulin secretion ; tumour necrosis factor.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Aims/hypothesis. To examine whether interferon-γ destroys islet beta cells directly or indirectly through lymphocyte activation, or whether direct action of interferon-γ on beta cells by itself induces diabetes without insulitis. Methods. To avoid possible nonspecific breakdown of beta cells by transgenic overexpression of interferon-γ by the insulin promoter, we generated transgenic mice expressing interferon-γ under the control of rat glucagon promoter (RGP-IFN-γ-Tg mice). Results. The absence of insulitis in RGP-IFN-γ-Tg mice enabled us to investigate the direct effects of paracrine interferon-γ. In RGP-IFN-γ-Tg mice, serum concentrations of interferon-γ and tumour necrosis factor-α (TNF-α) were 50 and 6 times higher than those in their littermates, respectively, and glucose-responsive insulin secretion decreased to one-half the level of that in the littermates. Transgenic interferon-γ induced remodelling of beta cells where apoptosis of many beta cells was compensated by their vigorous regeneration and diabetes did not occur in most of the RGP-IFN-γ-Tg mice. Conclusion/interpretation. Interferon-γ alone is insufficient for the complete destruction of beta cells in vivo, and factors other than interferon-γ including activated lymphocytes or other cytokines, are necessary in addition to interferon-γ for the development of Type I (insulin-dependent) diabetes mellitus. [Diabetologia (1999) 42: 566–573]
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  • 22
    ISSN: 1432-0428
    Keywords: Keywords Nicotinamide ; cytokine ; islet ; insulin ; apoptosis ; diabetes.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Nicotinamide intervention trials are presently undertaken to prevent Type I (insulin-dependent) diabetes in high risk subjects. They are based on studies in rodents reporting nicotinamide protection against beta-cell injury in vitro and in vivo. This study examines whether nicotinamide can protect human beta cells in vitro. At concentrations (2 and 5 mmol/l) to protect rat beta cells against necrosis by streptozotocin or hydrogen peroxide, nicotinamide prevents hydrogen peroxide-induced necrosis of human beta cells. As with rat beta cells, nicotinamide fails to protect human beta cells against apoptosis induced by a combination of the cytokines interleukin-1β , interferon-γ and tumour necrosis factor-α. In rat beta cells, nicotinamide (2 to 20 mmol/l) was also found to induce apoptosis, in particular during the days following its protection against necrosis; this cytotoxic effect was not observed with human beta cells. These data demonstrate that nicotinamide can protect human beta cells against radical-induced necrosis, but not against cytokine-induced apoptosis. This effect is not associated with a delayed apoptosis as in rat beta cells. [Diabetologia (1999) 42: 55–59]
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  • 23
    ISSN: 1423-0127
    Keywords: Tax ; HTLV-1 ; Trans-activation ; Phosphorylation ; Mutagenesis ; Transcription ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The human T cell leukemia virus type 1 (HTLV-1) Tax is a phosphoprotein, however, the contribution of phosphorylation to Tax activity is unknown. Previous studies have shown that phosphorylation of Tax occurs on serine residue(s), within one tryptic fragment, in response to 4β-phorbol-12β-myristate-13α-acetate, in both mouse and human cells. Studies were conducted in multiple cell lines to identify the specific phosphorylated serines as a prelude to functional analysis. The phosphorylation pattern of Tax was found to be different in 293T and COS-7 cells in comparison with MT-4 and Px-1 cells. However, one tryptic fragment remained consistent in comigration analyses among all cell lines. Using selected Tax serine mutants a tryptic fragment containing a serine at residue 113 believed to be the site of phosphorylation of Tax did not comigrate with the common phosphorylated tryptic fragment. Analysis of selected Tax mutants for ability totrans-activate the cytomegalovirus promoter demonstrated mutation of serine 77 to alanine reducedtrans-activation by 90% compared to wild-type Tax. However, examination of the phosphorylation pattern of the serine 77 mutant demonstrated that it is not the site of phosphorylation. These studies demonstrate the importance of using relevant cell lines to characterize the role of phosphorylation in protein function.
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  • 24
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Rhadomyosarkom ; Klassifizierung ; Immunhistochemie ; Genetik ; Prognose ; Key words Rhabdomyosarcoma ; Classification ; Immunohistochemistry ; Genetics ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Rhabdomyosarcoma (RMS) is the most important and a very heterogeneous group of malignant soft tissue tumors of childhood and adolescence.The two major subtypes (embryonal and alveolar) share a common myogenic differentiation, but seem to be histogenetically not related. The so-called ’International Classification of Rhabdomyosarcoma’ includes, besides the two major subtypes, the botryoid and leiomyomatous subtypes of embryonal RMS which are associated with a better prognosis and are treated less aggressively according to current protocols. In addition, the solid variant of alveolar RMS is included in the alveolar group of RMS. The identification of the various subtypes is necessary and important because the treatment with the current protocols is also related to histology. Using conventional stains and immunohistochemistry, these subtypes are distinguishable. Genetic analysis can be helpful in the demonstration of t(2;13) or t(1;13) translocations in alveolar RMS. The identification of alveolar RMS with t(1;13) translocation might become important in the future, because this type of translocation seems to be related to a better prognosis as compared to tumors with a t(2;13) translocation.
    Notes: Zusammenfassung Rhabdomyosarkome stellen eine heterogene Gruppe von ganz verschiedenartigen, histogenetisch wohl nicht zusammengehörenden Tumoren dar. Nach der heute verwendeten „Internationalen Klassifikation” der Rhabdomyosarkome werden neben der Unterteilung in embryonalen und alveoläre Rhabdomyossarkome auch Subtypen des embryonalen RMS identifiziert (botryoider und leiomyomatöser Subtyp), die durch eine günstigere Prognose und durch die Notwendigkeit einer weniger aggressive Therapie gekennzeichnet sind. Durch Einsatz von verschiedenen histologischen und immunhistochemischen Färbungen ist die Identifizierung der verschiedenen Typen der RMS heute möglich und auch zwingend notwendig, da die einzelnen Entitäten nach ganz unterschiedlichen Therapieprotokollen behandelt werden. Der Nachweis typischer molekulargenetischer Veränderungen kann in der Unterscheidung insbesondere von embryonalen und alveolären RMS hilfreich sein. In der Regel ist die Abgrenzung zwischen diesen beiden Entitäten auch an konventionell gefärbten Schnittpräparaten möglich. Die Identifizierung von alveolären RMS mit einer t(1;13)-Translokation könnte in Zukunft eine große Bedeutung haben, da diese genetische Veränderung möglicherweise mit einer günstigeren Prognose assoziert sein könnte als die t(2;13)-Translokation.
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  • 25
    ISSN: 1432-1076
    Keywords: Key words Congenital heart disease ; Pulmonary atresia and ventricular septal defect ; Genetics ; Monosomy 22q11.2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of our study was to describe the prevalence and the clinical spectrum of monosomy 22q11.2 in a population of patients with pulmonary atresia and ventricular septal defect. We examined all 44 patients with this conotruncal cardiac malformation who presented to our institution from January 1994 until December 1997. The type of collateral lung perfusion was recorded including anomalies of the pulmonary arteries as well as facial and immunological abnormalities. Molecular-cytogenetic testing for a 22q11.2 microdeletion was performed using the probes D22S75 and cHKAD26. Statistical differences were evaluated with the Fisher's Exact Test. Monosomy 22q11.2 was present in ten children (23%) with major aortopulmonary collateral arteries (group 1). The remaining 13 children (29%) with major aortopulmonary collateral arteries (group 2) and all 21 children (48%) with ductus arteriosus (group 3) were negative for this microdeletion. All children in group 1 had facial anomalies, six had mild immunological abnormalities including decreased CD 4+ or CD 8+ cells. Anomalies of the pulmonary vascular bed were significantly more frequent in children of group 1 (9/10) than in children of group 2 (4/13) or group 3 (0/21). Due to these pulmonary vascular anomalies, corrective surgery had been accomplished in fewer children with monosomy 22q11.2 (none in group 1) as compared to 7/13 children in group 2 and 14/21 children in group 3. Conclusion In children with pulmonary atresia and ventricular septal defect, monosomy 22q11.2 is preferentially associated with major aortopulmonary collateral arteries. Due to the higher incidence of pulmonary arterial abnormalities, successful surgical repair will require a different therapeutic approach in most patients with this microdeletion.
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  • 26
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    Current genetics 35 (1999), S. 571-584 
    ISSN: 1432-0983
    Keywords: Key words Cytokinesis ; Kinase ; Mitosis ; Schizosaccharomyces pombe ; Cell division ; Phosphatase ; Mutant ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells.
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  • 27
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    Journal of neurology 246 (1999), S. 1140-1144 
    ISSN: 1432-1459
    Keywords: Key words Amyotrophic lateral sclerosis ; Genetics ; Glutamate transporter gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurological disorder characterised by degeneration of upper and lower motor neurons. Whilst the primary pathogenic trigger is unknown in most cases, evidence is mounting to implicate a role for glutamate-mediated neurotoxicity in the disorder. Recent studies have shown reduced levels of the mainly astroglial glutamate transporter EAAT2 in ALS motor cortex and spinal cord and multiple abnormal EAAT2 mRNA species in ALS brain tissue. One cause of the low EAAT2 levels may be that point mutations in the EAAT2 gene, EAAT2, result in an abnormal unstable protein. To test this hypothesis we analysed EAAT2 in 128 sporadic and 23 familial European ALS cases. No variants within the coding sequence of EAAT2 to affect the protein sequence nor in the consensus splice sites of the flanking intronic sequences were found in any cases, similar to findings in other reports. Frequent polymorphisms within the flanking intronic sequences of both exons 2 and 4 were seen but at similar frequencies in controls. Mechanisms other than mutations within the coding region of EAAT2 must therefore be responsible for the low levels of EAAT2 seen in most cases of ALS.
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  • 28
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    International journal of colorectal disease 14 (1999), S. 2-9 
    ISSN: 1432-1262
    Keywords: Key words Inflammatory bowel disease ; Crohn's disease ; Ulcerative colitis ; Epidemiology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Inflammatory bowel diseases (IBD) are complex disorders. While the exact etiology of these diseases remains unknown, recent progress in the epidemiology and genetics of IBD has clearly demonstrated both environmental and genetic factors to play a role in the development of the disease, and it is expected that some risk factors are common for both Crohn's disease (CD) and ulcerative colitis (UC). The environmental factor(s) are associated with the Western way of life in the second half of the twentieth century. Cigarette smoking is presently the best known environmental factor. However, the effect of tobacco is opposite in CD and UC. A familial history of IBD is the most important risk factor for developing the disease, suggesting a genetic predisposition to IBD. This hypothesis has recently been confirmed by the localization of at least two susceptibility loci on chromosomes 12 and 16. These genes seem to play a role in both CD and UC. They must now to be identified.
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  • 29
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    Child's nervous system 15 (1999), S. 676-680 
    ISSN: 1433-0350
    Keywords: Key words Craniosynostosis ; Genetics ; FGFR ; Msx2 ; Development ; Skull
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The genetic studies of syndromic craniosynostoses lead to the characterisation of genes that regulate the correct development of the bones of the skull. From these studies, it appears that FGF/FGFR signalling has a crucial role in this problem. Numerous mutations affecting the genes coding for FGFR1, 2 or 3 are responsible for these syndromes. It is interesting to note that some identical mutations produced various different phenotypes, suggesting that other genes modulate the phenotypic expressivity. The other involved genes in these syndromes code for such proteins as Msx2 or Twist that interact in the cellular pathways responsible for FGF action. From these genetic studies, it is now important to establish the role of these proteins during the development of the skull. Msx2 plays a repressive role in osteogenesis, whereas FGFRs act as promoting proteins. In the near future, it will be very important to improve our understanding of these phenomena in order to test specific treatments to prevent the development of such syndromes.
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  • 30
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    Journal of neurology 246 (1999), S. 69-72 
    ISSN: 1432-1459
    Keywords: Key words Alzheimer’s disease ; Genetics ; Genetic counseling ; Predictive testing ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alzheimer’s disease (AD) has a significant genetic background manifested as autosomal dominant inheritance in some early-onset families and as familial risk in late-onset cases. Three genes responsible for early-onset autosomal dominant AD have been identified, and one gene, apolipoprotein E, has been confirmed as a susceptibility gene for late-onset forms of the disorder. These findings raise the possibility of genetic testing, either for early diagnosis or prediction. For early-onset autosomal dominant AD genetic testing will have a limited but useful role in confirming diagnosis in established cases and in predictive counselling for relatives; a situation analogous to that for Huntington’s disease. For late-onset AD significant problems remain to be overcome before the advances in molecular genetics have a direct clinical application
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  • 31
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    Annals of oncology 10 (1999), S. 139-150 
    ISSN: 1569-8041
    Keywords: apoptosis ; chemotherapy ; clinical trials ; gene therapy ; p53
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nearly twenty years after the initial discovery of p53, we are now in an ideal position to exploit our vast knowledge of p53 biology in the creation of novel cancer therapies. Disruption of p53 function through mutation, or other means, occurs very frequently in human cancer. Loss of p53 function has been linked with unfavourable prognosis in a large number of tumour types, as indicated by more aggressive tumours, early metastasis and decreased survival rates. Many different avenues of research have converged upon p53 to highlight this protein as being one of the foremost cellular responders to stress, in particular to DNA damage. Huge advances have been made in understanding the complex role p53 plays in the regulation of apoptosis and cell cycle arrest. This review is not meant to be a comprehensive description of p53 biology, but rather serves to highlight current progress in the development of p53- oriented cancer therapies. These may be categorised into three basic strategies: gene replacement therapy using wild-type p53, restoration of p53 function by other means and, finally, targeting of the p53 dysfunction itself. Rapid progress is expected to be made regarding the identification of conventional pharmaceutical agents which either work in a p53-independent manner or act preferentially in p53 defective cells. Gene replacement therapy with wild-type p53 also holds considerable potential for obtaining clinically relevant results quickly. The other forms of cancer therapies based around p53 are much further behind in the developmental process, but may prove to more efficacious in the long run, especially in terms of specificity. As with many other fields, the innovation of successful p53-oriented cancer therapies is only limited by our understanding of p53 biology and the creative use of such knowledge.
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  • 32
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    Annals of oncology 10 (1999), S. 122-126 
    ISSN: 1569-8041
    Keywords: apoptosis ; biliary carcinogenesis ; cholangiocarcinoma ; genotoxicity ; risk factors ; therapeutic strategies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Carcinomas of the biliary tract are rare cancers developing from the epithelial or blast-like cells lining the bile ducts. A variety of known predisposing factors and recent experimental models of biliary carcinogenesis (e.g., infection with the liver fluke Opisthorchis viverrini, models of chemically induced carcinogenesis and experimental models of pancreaticobiliary maljunction) have elucidated different stages of this complex system of biliary tumorigenesis. Chronic inflammatory processes, generation of active oxygen radicals, altered cellular detoxification mechanisms, activation of oncogenes, functional loss of tumor-suppressor genes and dysregulation of cell proliferation and cell apoptotic mechanisms have been identified as important contributors in the development of cholangiocarcinomas. In this review, the known mechanisms involved in the carcinogenesis of biliary epithelium are addressed. We will divide the topic into four stages: 1) Predisposition and risk factors of biliary cancer, 2) Genotoxic events and alterations leading to specific DNA damage and mutation patterns. 3) Dysregulation of DNA repair mechanisms and apoptosis, permitting survival of mutated cells and 4) Morphological evolution from premalignant biliary lesions to cholangiocarcinoma. Finally, established and hypothetical future therapeutic strategies directed towards specific pathogenetic events during biliary carcinogenesis will be addressed.
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  • 33
    ISSN: 1569-8041
    Keywords: acute myelogenous leukemia ; apoptosis ; ara-CTP ; cytosine arabinoside ; HL-60 ; retinoic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Accumulation of the cytosine arabinoside (ara-C) metabolite ara-C-triphosphate (ara-CTP) in leukemic blast cells is considered to be the main determinant of ara-C cytotoxicity in vitro and in vivo. Retinoids such as all-trans-retinoic acid (ATRA) have been shown to increase the sensitivity of acute myelogenous leukemic (AML) blast cells to ara-C. To investigate the mechanism of this sensitisation, the hypothesis was tested that ATRA augments cellular ara-CTP levels in human-derived myelogenous leukemia HL-60 cells. Materials and methods: The effect of ATRA and 13-cis-retinoic acid on ara-CTP accumulation and ara-C-induced apoptosis was studied. Ara-CTP levels were measured by high-performance liquid chromatography (HPLC), cytotoxicity by the tetrazolium (MTT) assay, and apoptosis by occurrence of DNA fragmentation (gel electrophoresis), cell shrinkage and DNA loss (flow cytometry). Results: Pretreatment of HL-60 cells with ATRA (0.01–1 µM) caused a significant decrease in intracellular ara-CTP levels; e.g., incubation for 72 hours with ATRA 1 µM prior to one hour ara-C 10 µM reduced ara-CTP levels to 41% ± 4% of control. Similar results were obtained after preincubation with 13-cis-retinoic acid. In spite of decreased ara-CTP levels, the cytotoxicity of the combination was supraadditive and ATRA augmented ara-C-induced apoptosis. Conclusions: At therapeutically relevant concentrations ATRA increased ara-C cytotoxicity and ara-C induced apoptosis but this augmentation is not the corollary of elevated ara-CTP levels. The feasibility of ara-C treatment optimisation via strategies other than those involving elevation of ara-CTP levels should be investigated further.
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  • 34
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    Molecular and cellular biochemistry 196 (1999), S. 13-21 
    ISSN: 1573-4919
    Keywords: apoptosis ; DNA fragmentation ; GSHPx-1 knockout mice ; GSHPx-1 transgenic mice ; ischemia/repurfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Apoptosis, a genetically controlled programmed cell death, has been found to play a role in ischemic reperfusion injury in several animal species including rats and rabbits. To examine whether this is also true for other animals, an isolated perfused mouse heart was subjected to 30 min of ischemia followed by 2 h of reperfusion. Experiments were terminated before ischemia (baseline), after ischemia, and at 30, 60, 90 and 120 min of reperfusion. At the end of each experiment, hearts were processed for the evaluation of apoptosis and DNA laddering. The in situ end labeling (ISEL) technique was used to detect apoptotic cardiomyocyte nuclei while DNA laddering was evaluated by subjecting the DNA obtained from the cardiomyocytes to 1.8% agarose gel electrophoresis followed by photographing under UV illumination. The results of our study revealed that apoptotic cells appear only after 60 min of reperfusion as demonstrated by the intense fluorescence of the immunostained genomic DNA when observed under fluorescence microscopy. None of the ischemic hearts showed any evidence of apoptosis. These results were corroborated with the findings of DNA fragmentation showing increased ladders of DNA bands in the same reperfused hearts representing integer multiples of the internucleosomal DNA length (about 180 bp). Since our previous studies showed a role of glutathione peroxidase (GSHPx) in apoptotic cell death, we performed identical experiments using isolated hearts from GSHPx-l knockout mice and transgenic mice overexpressing GSHPx-l. GSHPx-l knockout mice showed evidence of apoptotic cell death even after 30 min of reperfusion. Significant number of apoptotic cells were found in the cardiomyocytes as compared to non-transgenic control animals. To the contrary, very few apoptotic cells were found in the hearts of the transgenic mice overexpressing GSHPx-l. Hearts of GSHPx-l knockout mice were more susceptible to ischemia/reperfusion injury while transgenic mice overexpressing GSHPx- 1 were less susceptible to ischemia reperfusion injury compared to non-transgenic control animals. The results of this study clearly demonstrate a role of GSHPx in ischemia/reperfusion-induced apoptosis in mouse heart.
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  • 35
    ISSN: 1573-4919
    Keywords: MKP-1 ; Fas ligand ; Fas ; apoptosis ; prostate cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Recent studies have suggested that MAP kinase phosphatase 1 (MKP-1) is overexpressed in prostate cancer. To evaluate the role of MKP-1 in regulating cell death and tumor growth in prostate cancer, MKP-1 was conditionally overexpressed in the human prostate cancer cell line DU145. Overexpression of MKP-1 in DU145 cells blocked activation of stress-activated protein kinase (SAPK/JNK). MKP-1 overexpression in DU-145 cells was also found to inhibit Fas ligand (FasL)-induced apoptosis, as well as block the activation of caspases by Fas engagement. In addition, MKP-1 blocked the activation of apoptosis by transfected MEKK-1 and ASK-1, presumably through its inhibition of the SAPK/JNK family of enzymes. MKP-1 blocked the ability of FasL to induce loss of mitochondrial transmembrane potential (Δγm), suggesting that MKP-1 acts upstream of mitochondrial pro-apoptotic events induced by FasL and that the SAPK/JNK pathway may form the signaling link between Fas receptor and mitochondrial dysfunction. Thus, MKP-1 overexpression in prostate cancer may play a role in promoting prostate carcinogenesis by inhibiting FasL-induced cell death.
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  • 36
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    Molecular and cellular biochemistry 199 (1999), S. 125-137 
    ISSN: 1573-4919
    Keywords: apoptosis ; ADP-ribosylation ; caspases ; PARP ; PARG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Poly(ADP-ribosylation) is a post-translational modification playing a relevant role in DNA damage recovery, DNA replication and viral integration. Several reports also suggest a modulation of this process during cell death by apoptosis. The aim of this review is to discuss the possible involvement of poly(ADP-ribosylation) during apoptosis, by dealing with general considerations on apoptosis, and further examining the correlation between NAD consumption and cell death, the regulation of poly(ADP-ribose) metabolism in apoptotic cells, the effect of poly(ADP-ribose) polymerase inhibition on cell death occurrence and the use of enzyme cleavage as a marker of apoptosis. Finally, the future prospects of the research in this area will be addressed.
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  • 37
    ISSN: 1573-4919
    Keywords: DNA binding protein ; NAD metabolism ; cellular response to DNA damage ; γ-rays ; alkylating agents ; genomic instability ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract A dual approach to the study of poly (ADP-ribose)polymerase (PARP) in terms of its structure and function has been developed in our laboratory. Random mutagenesis of the DNA binding domain and catalytic domain of the human PARP, has allowed us to identify residues that are crucial for its enzymatic activity. In parallel PARP knock-out mice were generated by inactivation of both alleles by gene targeting. We showed that: (i) they are exquisitely sensitive to γ-irradiation, (ii) they died rapidly from acute radiation toxicity to the small intestine, (iii) they displayed a high genomic instability to γ-irradiation and MNU injection and, (iv) bone marrow cells rapidly underwent apoptosis following MNU treatment, demonstrating that PARP is a survival factor playing an essential and positive role during DNA damage recovery and survival.
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  • 38
    ISSN: 1573-4919
    Keywords: PARP ; poly(ADP-ribosyl)ation ; apoptosis ; DNA replication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract We have focused on the roles of PARP and poly(ADP-ribosyl)ation early in apoptosis, as well as during the early stages of differentiation-linked DNA replication. In both nuclear processes, a transient burst of PAR synthesis and PARP expression occurs early, prior to internucleosomal DNA cleavage before commitment to apoptosis as well as at the round of DNA replication prior to the onset of terminal differentiation. In intact human osteosarcoma cells undergoing spontaneous apoptosis, both PARP and PAR decreased after this early peak, concomitant with the inactivation and cleavage of PARP by caspase-3 and the onset of substantial DNA and nuclear fragmentation. Whereas 3T3-L1, osteosarcoma cells, and immortalized PARP +/+ fibroblasts exhibited this early burst of PAR synthesis during Fas-mediated apoptosis, neither PARP-depleted 3T3-L1 PARP-antisense cells nor PARP -/- fibroblasts showed this response. Consequently, whereas control cells progressed into apoptosis, as indicated by induction of caspase-3-like PARP-cleavage activity, PARP-antisense cells and PARP -/- fibroblasts did not, indicating a requirement for PARP and poly(ADP-ribosyl)ation of nuclear proteins at an early reversible stage of apoptosis. In parallel experiments, a transient increase in PARP expression and activity were also noted in 3T3-L1 preadipocytes 24 h after induction of differentiation, a stage at which ~95% of the cells were in S-phase, but not in PARP-depleted antisense cells, which were consequently unable to complete the round of DNA replication required for differentiation. PARP, a component of the multiprotein DNA replication complex (MRC) that catalyzes viral DNA replication in vitro, poly(ADP-ribosyl)ates 15 of ~40 MRC proteins, including DNA pol α, DNA topo I, and PCNA. Depletion of endogenous PARP by antisense RNA expression in 3T3-L1 cells results in MRCs devoid of any DNA pol α and DNA pol δ activities. Surprisingly, there was no new expression of PCNA and DNA pol α, as well as the transcription factor E2F-1 in PARP-antisense cells during entry into S-phase, suggesting that PARP may play a role in the expression of these proteins, perhaps by interacting with a site in the promoters for these genes.
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  • 39
    ISSN: 1573-4919
    Keywords: breast cancer cells ; anti-apoptotic genes ; apoptosis ; progesterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Progesterone inhibits the proliferation of normal breast epithelial cells in vivo, as well as breast cancer cells in vitro. But the biologic mechanism of this inhibition remains to be determined. We explored the possibility that an antiproliferative activity of progesterone in breast cancer cell lines is due to its ability to induce apoptosis. Since p53, bcl-2 and survivin genetically control the apoptotic process, we investigated whether or not these genes could be involved in the progesterone-induced apoptosis. We found a maximal 90% inhibition of cell proliferation with T47-D breast cancer cells after exposure to 10 μM progesterone for 72 h. Control progesterone receptor negative MDA-231 cancer cells were unresponsive to 10 μM progesterone. The earliest sign of apoptosis is translocation of phosphatidylserine from the inner to the outer leaflet of the plasma membrane and can be monitored by the calcium-dependent binding of annexin V in conjunction with flow cytometry. After 24 h of exposure to 10 μM progesterone, cytofluorometric analysis of T47-D breast cancer cells indicated 43% were annexin V-positive and had undergone apoptosis and no cells showed signs of cellular necrosis (propidium iodide negative). After 72 h of exposure to 10 μM progesterone, 48% of the cells had undergone apoptosis and 40% were annexin V positive/propidium iodide positive indicating signs of necrosis. Control untreated cancer cells did not undergo apoptosis. Evidence proving apoptosis was also demonstrated by fragmentation of nuclear DNA into multiples of oligonucleosomal fragments. After 24 h of exposure of T47-D cells to either 1 or 10 μM progesterone, we observed a marked down-regulation of protooncogene bcl-2 protein and mRNA levels. mRNA levels of survivin and the metastatic variant CD44 v7-v10 were also downregulated. Progesterone increased p53 mRNA levels. These results demonstrate that progesterone at relative high physiological concentrations, but comparable to those seen in plasma during the third trimester of human pregnancy, exhibited a strong antiproliferative effect on breast cancer cells and induced apoptosis.
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  • 40
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    Molecular and cellular biochemistry 200 (1999), S. 51-57 
    ISSN: 1573-4919
    Keywords: smokeless tobacco ; apoptosis ; nitric oxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Smokeless tobacco usage is, a growing public health concern in the United States. Lesions of the oral cavity have been clearly linked to smokeless tobacco use. The objective of this study was to determine the biochemical effects of smokeless tobacco extract (STE) exposure upon hamster cheek pouch cell (HCPC-1) cultures. HCPC-1 cells were exposed to a 5 -fold dose-range of STE (0.5, 1.0 and 2.5%) over a time-course of 24-96 h. Following each exposure we measured various biochemical parameters of cell proliferation and cell death. Cell viability, cell cycle progression and S-phase DNA synthesis were measured as markers of cell proliferation. We measured lactate dehydrogenase leakage as a marker of cell membrane damage and cell death due to necrosis. No significant alterations were observed in cell cycle progression and cell proliferation as a result of exposure to STE. LDH measured colorimetrically indicated no significant effect with the lower doses (0.5, 1.0 and 2.5% STE). Apoptosis measured as the A0 peak and by the TUNEL procedure revealed that STE caused significant rates of apoptosis. Maximal apoptosis was noted between 48-96 h. In order to probe the mechanism further we measured the levels of nitrites as an indicator of nitric oxide (NO) in the media. NO levels were significantly elevated at the doses that caused an induction of apoptosis. The results from this study indicate that STE causes a dose-dependent induction of apoptosis and that this is mediated by nitric oxide.
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  • 41
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    Molecular and cellular biochemistry 193 (1999), S. 37-42 
    ISSN: 1573-4919
    Keywords: Rho ; GTPase ; toxins ; Clostridium ; signal transduction ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The Rho family small GTPases are members of the Ras superfamily of small GTPases. Rho proteins were first determined to act as key regulators of many types of actin cytoskeletal-dependent cellular functions. Recent work by several investigators indicates that Rho GTPases are also critical modulators of several important intracellular and nuclear signal transduction pathways. Certain clostridial toxins and exoenzymes covalently modify, and thereby inactivate, specific types of Rho family GTPases. As such, these microbial enzymes have proven invaluable in helping to identify structural and functional attributes of Rho GTPases.
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  • 42
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    Molecular and cellular biochemistry 193 (1999), S. 103-108 
    ISSN: 1573-4919
    Keywords: Poly(ADP-ribose) polymerase ; Drosophila melanogaster ; alternative splicing ; apoptosis ; DNA repair ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Poly(ADP-ribose) polymerase (PARP) is conserved in eukaryotes. To analyze the function of PARP, we isolated and characterized the gene for PARP in Drosophila melanogaster. The PARP gene consisted of six translatable exons and spanned more than 50 kb. The DNA binding domain is encoded by exons 1-4. Although the consensus cleavage site of CED-3 like protease during apoptosis is conserved from human to Xenopus laevis PARPs, it is neither conserved in the corresponding region of Drosophila nor Sarcophaga peregrina. There are two cDNAs species in Drosophila. One cDNA could encode the full length PARP protein (PARP I), while the other is a truncated cDNA which could encode a partial-length PARP protein (PARP II), which lacks the automodification domain and is possibly produced by alternative splicing. The expression of these two forms of PARP in E. coli demonstrated that while PARP II has the catalytic NAD-binding domain and DNA-binding domain it is enzymatically inactive. On the other hand PARP I is active. A deletion mutant of PARP gene could grow to the end of embryogenesis but did not grow to the adult fly. These results suggest that the PARP gene plays an important function during the development of Drosophila.
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  • 43
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    Molecular and cellular biochemistry 193 (1999), S. 119-125 
    ISSN: 1573-4919
    Keywords: benzamides ; nicotinamides ; apoptosis ; inflammation ; NF-kB ; DNA repair
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Our laboratory has concentrated on the possible regulation the benzamides and nicotinamides may have on the processes of DNA repair and apoptosis. Recent reports [14-16] have suggested that both apoptosis and inflammation are regulated by the transcription factor NF-kB. We have initiated studies regarding the hypothesis that the benzamides and nicotinamides could inhibit the production of tumor necrosis factor alpha (TNFalpha) and the inflammatory response as well as induce apoptosis via inhibition of NF-kB. Our data have shown that nicotinamide and two N-substituted benzamides, metoclopramide (MCA) and 3-chloroprocainamide (3-CPA), gave dose dependent inhibition of lipopolysacharide induced TNFalpha in the mouse within the dose range of 10-500 mg/kg. Moreover, lung edema was prevented in the rat by 3 ï 50 mg/kg doses of 3-CPA or MCA, and 100-200 μM doses of MCA could also inhibit NF-kB in Hela cells. Taken together these data strongly support the notion that benzamides and nicotinamides have potent anti-inflammatory and antitumor properties, because their primary mechanism of action is regulated by inhibition at the gene transcription level of NF-kB, which in turn inhibits TNFalpha and induces apoptosis.
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  • 44
    ISSN: 1573-4919
    Keywords: antisense oligonucleotide ; apoptosis ; cAMP-dependent protein kinase ; cancer cells ; growth inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The enhanced expression of the RIα subunit of cyclic AMP-dependent protein kinase type 1 (PKA-I) has been correlated with cancer cell growth. We have investigated the effects of sequence-specific inhibition of RIα gene expression on the growth of MCF-7 human breast cancer cells. We report that RIα antisense treatment results in a reduction in RIα expression at both mRNA and protein levels and inhibition of cell growth. The growth inhibition was accompanied by changes in cell morphology, cleavage of poly(ADP-ribose) polymerase (PARP) and appearance of apoptotic nuclei. In addition, bcl-2 protein level was reduced and p53 expression increased in growth arrested cells. Interestingly, RIα antisense inhibited cell viability and induced apoptosis in the absence of p53, suggesting that these actions of RIα antisense are exerted independent of p53. In contrast, two- and four-base mismatched control oligonucleotides had no effect on either cell growth or morphology. These results demonstrate that the RIα antisense, which efficiently depletes the growth stimulatory molecule RIα, induces cell differentiation and apoptosis, providing a new approach to combat breast cancer cell growth.
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  • 45
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    Molecular and cellular biochemistry 197 (1999), S. 97-108 
    ISSN: 1573-4919
    Keywords: neutrophil ; PKC ; TNF-α ; apoptosis ; DNA fragmentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract In the present study we investigated the TNF-α induced signal transduction mechanism in human neutrophil. Exogenously added TNF-α affects both PKC activity and its translocation from cytosol to the membrane. Endogenous protein phosphorylation pattern is inhibited in TNF-α induced neutrophil in Ca-dependent and Ca-independent manner, including a major 47 and 66 kDa cytosolic proteins, which may be implicated in superoxide anion generation. However TNF-α dose dependently enhances the expression of ζ-PKC isotype but not the β-PKC. Morphology and cell cytotoxicity are studied in TNF-α treated neutrophil to understand the TNF-α induced cell death or apoptosis and these experiment is further confirmed by DNA fragmentation analysis. These results clearly demonstrate that TNF-α induces cellular death of human neutrophil at least in part by enhanced expression of Ca-independent ζ-PKC. These observations provide an insight towards understanding the function of ζ-PKC in apoptotic pathway.
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  • 46
    ISSN: 1573-4919
    Keywords: rotenone ; apoptosis ; oncogenes ; liver cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Rotenone decreases the incidence of hepatocellular carcinoma and lowers rates of hepatocellular proliferation. In an effort to delineate mechanisms involved, the in vivo effect of rotenone on liver mitochondrial metabolism, apoptotic machinery as well as elements of the hepatic signal transduction pathways were investigated. Mitochondria from livers of male B6C3F1 mice fed a standard diet containing 600 ppm rotenone for 7 days were uncoupled or inhibited when succinate or glutamate plus malate were used as the substrate, respectively. These livers also showed a significant increase in apoptosis compared with control livers. Furthermore, rotenone increased the expression of c-myc mRNA to 5-fold of control values within 3 days, an effect which was still observed (3-fold) after 7 days. Levels of p53 mRNA were also increased 3-fold after 1 day, but declined to control levels by 7 days. Rotenone also caused a transient, yet marked increase in liver particulate glyceraldehyde phosphate dehydrogenase (GAPDH) protein expression, while it did not alter the expression of the cytosolic form of the enzyme. Conversely, mRNA of the proto-oncogene H-ras showed a decline of 35% after 3 days of rotenone treatment, and remained diminished for the duration of the experiment. These data suggest that rotenone may act as an anticancer agent by diminishing mitochondrial bioenergetics which prevents basal hepatocyte proliferation and lowers the threshold for liver cells with DNA damage to undergo apoptosis.
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  • 47
    ISSN: 1573-4943
    Keywords: Two-dimensional electrophoresis ; MALDI-MS ; apoptosis ; RNA polymerase B transcription factor 3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Apoptosis or programmed cell death is essential in the process of controlling lymphocyte growth and selection. We identified RNA polymerase B transcription factor 3 (BTF3), which is associated with anti-IgM antibody-mediated apoptosis, using a subclone of the human Burkitt lymphoma cell line BL60. To identify the transcription factor BTF3, which is expressed only in minor amounts, we used preparative high-resolution two-dimensional gel electrophoresis (2DE) employing carrier ampholytes for isoelectric focusing. Comparison of the 2DE protein patterns from apoptotic and nonapoptotic cells showed BTF3 as a predominantly altered protein spot. The characterization of the differentially expressed transcription factor and 13 marker proteins described in this study were performed by internal Edman microsequencing and/or by peptide mass fingerprinting using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The proteome analysis was significantly improved by performing the newly developed preparative high-resolution two-dimensional gels employing high protein concentrations.
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  • 48
    ISSN: 1432-5233
    Keywords: Key words Mitochondrial DNA ; Genetics ; Maternally inherited diabetes mellitus ; Deafness ; np 3243 mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Mitochondrial DNA (mtDNA) gene defects may play a role in the development of maternally inherited diabetes mellitus and deafness (MIDD). A family from Southern Italy who showed maternal transmission of type 2 diabetes mellitus with three individuals affected is described. A 10.4 kb deletion and mutations at nucleotide positions (np) 3243, 7445 and 11778 in the mtDNA of six relatives were sought. The mitochondrial np 3243 mutation of the tRNA Leu (UUR) gene was identified in a boy affected by optic atrophy and mental retardation, as well as in his diabetic mother. No other mutations or deletions were found. Our study points out the variable phenotypic expression of the np 3243 mtDNA mutation. This may suggest the presence of other mitochondrial or nuclear mutations required to modulate the phenotype. A clinical and metabolic follow-up of all family members was necessary to understand the role of the np 3243 mutation, especially in one child affected by optic atrophy and mental retardation. Further studies will be aimed at investigating the prevalence of mutations and deletions of mtDNA in type 2 diabetes mellitus.
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  • 49
    ISSN: 1432-2242
    Keywords: Key words Passiflora ; Self-incompatibility ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The self-incompatibility in yellow passion fruit was previously described as homomorphic sporophytic with monofactorial inheritance. Five progenies were obtained by bud-selfing. The plants of these progenies were selfed, reciprocally crossed within each progeny and crossed with known incompatible phenotypes to identify their phenotypic group. Fruit set was evaluated at the 7th day after pollination. Two progenies consisted of two self-incompatible groups, the other three formed three suck groups. The groups were identified as S1, S2, S3, S4, S5 and S6. The results provide evidence that the self-incompatibility of passion fruit is controlled by two loci, the S-gene and another, whose expression needs to be investigated.
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  • 50
    ISSN: 1432-2242
    Keywords: Key words Simple sequence repeat (SSR) ; Microsatellites ; Molecular markers ; Genetics ; Fingerprinting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We report the sequences of 17 primer pairs of microsatellite loci, which we have cloned and sequenced from two genomic libraries of peach [Prunus persica (L) Batsch] ‘Redhaven’, enriched for AC/GT and AG/CT repeats respectively. For ten of these microsatellite loci we were able to demonstrate Mendelian inheritance in a segregating back-cross population; the remainder did not segregate. The polymorphism of the microsatellites was evaluated in a panel of ten peach genotypes, including true-to-type peaches, nectarines and one canning-peach. Fifteen microsatellites (88%) were polymorphic showing 2–4 alleles each. The mean heterozygosity, averaged over all loci, was 0.32 and significantly higher than that reported in the literature for isozymes and molecular markers, such as RFLPs and RAPDs. We have also assayed the cross-species transportability and found that ten microsatellite (59%) gave apparently correct amplification in all Prunus species surveyed, namely P. domestica (European plum), P. salicina (Japanese plum), P. armeniaca (apricot), P. dulcis (almond), P. persica var. vulgaris (peach), P. persica var. laevis (nectarine), P. avium (sweet cherry) and P. cerasus (sour cherry), with three of them also being amplified in Malus (apple). The remaining microsatellites gave less-extensive amplification. Because of their appreciable polymorphism and wide cross-species transportability, most of these new markers can be integrated into the linkage maps which are currently being constructed in peach, as well as in other stone fruit crops, such as almond, apricot, cherry and plum.
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  • 51
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    Theoretical and applied genetics 99 (1999), S. 800-810 
    ISSN: 1432-2242
    Keywords: Key words Almond ; Compatibility ; Genetics ; Prunus dulcis ; Ribonucleases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Six almond progenies, each the product of a cross between a self-compatible and a self-incompatible parent, were analysed for stylar ribonucleases. Proteins were extracted and separated using non-equilibrium pH gradient electrofocusing (NEPHGE), and the gels were stained for ribonuclease activity. Most seedlings showed either two principal bands, interpreted as corresponding to two incompatibility alleles, or a single band. The seedlings were also bagged in the field at flowering time to determine fruit set after selfing, and some were also examined for the growth of pollen-tubes in selfed styles using UV fluorescence microscopy. With very few exceptions, those seedlings showing single-banded zymograms were found to be self-compatible according to field and microscope studies, and those with two bands were found to be self-incompatible. We conclude that the allele for self-compatibility in almond does not code for ribonuclease activity and that the ribonuclease isoenzyme assay is a convenient technique for predicting self-compatibility in segregating progenies. A novel band in two derivatives of ’Ferrastar’ was ascribed to a new incompatibility allele, S 10 .
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  • 52
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    Behavioral ecology and sociobiology 46 (1999), S. 171-179 
    ISSN: 1432-0762
    Keywords: Key words Honeybee ; Apis mellifera ; Division of labor ; Genetics ; Pollen foraging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A fundamental requirement of task regulation in social groups is that it must allow colony flexibility. We tested assumptions of three task regulation models for how honeybee colonies respond to graded changes in need for a specific task, pollen foraging. We gradually changed colony pollen stores and measured behavioral and genotypic changes in the foraging population. Colonies did not respond in a graded manner, but in six of seven cases showed a stepwise change in foraging activity as pollen storage levels moved beyond a set point. Changes in colony performance resulted from changes in recruitment of new foragers to pollen collection, rather than from changes in individual foraging effort. Where we were able to track genotypic variation, increases in pollen foraging were accompanied by a corresponding increase in the genotypic diversity of pollen foragers. Our data support previous findings that genotypic variation plays an important role in task regulation. However, the stepwise change in colony behavior suggests that colony foraging flexibility is best explained by an integrated model incorporating genotypic variation in task choice, but in which colony response is amplified by social interactions.
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  • 53
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    Investigational new drugs 17 (1999), S. 227-240 
    ISSN: 1573-0646
    Keywords: apoptosis ; protein kinase C ; sphingoid bases ; safingol ; diglyceride ; bryostatin 1 ; staurosporine ; 7-hydroxy staurosporine (UCN-01) ; 4′-N-benzoyl staurosporine (CGP-41251) ; calphostin C (UCN-1028c)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Neoplastic cell survival is governed by a balance between pro-apoptotic and anti-apoptotic signals. Noteworthy among several anti-apoptotic signaling elements is the protein kinase C (PKC) isoenzyme family, which mediates a central cytoprotective effect in the regulation of cell survival. Activation of PKC, and subsequent recruitment of numerous downstream elements such as the mitogen-activated protein kinase (MAPK) cascade, opposes initiation of the apoptotic cell death program by diverse cytotoxic stimuli. The understanding that the lethal actions of numerous antineoplastic agents are, in many instances, antagonized by cytoprotective signaling systems has been an important stimulus for the development of novel antineoplastic strategies. In this regard, inhibition of PKC, which has been shown to initiate apoptosis in a variety of malignant cell types, has recently been the focus of intense interest. Furthermore, there is accumulating evidence that selective targeting of PKC may prove useful in improving the therapeutic efficacy of established antineoplastic agents. Such chemosensitizing strategies can involve either (a) direct inhibition of PKC (e.g., following acute treatment with relatively specific inhibitors such as the synthetic sphingoid base analog safingol, or the novel staurosporine derivatives UCN-01 and CGP-41251) or (b) down-regulation (e.g., following chronic treatment with the non-tumor-promoting PKC activator bryostatin 1). In preclinical model systems, suppression of the cytoprotective function(s) of PKC potentiates the activity of cytotoxic agents (e.g., cytarabine) as well as ionizing radiation, and efforts to translate these findings into the clinical arena in humans are currently underway. Although the PKC-driven cytoprotective signaling systems affected by these treatments have not been definitively characterized, interference with PKC activity has been associated with loss of the mitogen-activated protein kinase (MAPK) response. Accordingly, recent pre-clinical studies have demonstrated that pharmacological disruption of the primary MEK-ERK module can mimic the chemopotentiating and radiopotentiating actions of PKC inhibition and/or down-regulation.
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  • 54
    ISSN: 1573-0646
    Keywords: UCN-01 ; IL-2 receptor ; Fas ; Fas-ligand ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract 7-hydroxystaurosporine (UCN-01) is a new anticancer agentwhich exerts an inhibitory effect on cell cycle check points andis currently under phase I clinical trials in US and Japan.Preliminary clinical data indicated that UCN-01 remained inplasma at high concentrations for long periods of time. Thisunavoidable high plasma drug exposure is likely to lead tohematological toxicities in patients. In the present study,cultured human peripheral blood lymphocytes (PBLs) were used toevaluate the possible hematological toxicities of UCN-01treatment. UCN-01 induces apoptosis, and the induction ofapoptosis-related surface markers were also examined toinvestigate the involvement of these molecules in UCN-01-inducedapoptosis in PBLs. in vitroviability of PBLs wasdecreased by high dose of UCN-01 (25 μM, 3-day exposure). Thiseffect of UCN-01 was significantly suppressed by the presence ofhuman serum, suggesting that some specific inhibitory factor(s)in human serum may antagonize the lympholytic effect of UCN-01.The percentage of annexin V-positive PI-negative cells increasedwith exposure to UCN-01 in a time- and dose-dependent manner; byup to 30.3% after exposure to 25 μM UCN-01 for 3 days.At the same time, the expression of both interleukin-2 receptor(IL-2R, CD25) and Fas (CD95), analyzed by flow cytometry, wasinduced. Con A-stimulated PBLs were more sensitive toUCN-01-induced apoptosis than non-stimulated lymphocytes andUCN-01 increased the sFas-L released into culture medium from conA-stimulated PBLs. Therefore, lymphocyte depletion mediated byactivation-induced apoptosis is likely to occur in patientstreated with UCN-01 at high doses.
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  • 55
    ISSN: 1573-0778
    Keywords: apoptosis ; Bcl-2 ; fixed-bed ; hollow fibre ; hybridoma ; perfusion ; protein-free medium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Apoptosis is an active, genetically determined death mechanism which can be induced by a wide range of physiological factors and by mild stress. It is the predominant form of cell death during the production of antibodies from murine hybridoma cell lines. A number of studies have now demonstrated that the suppression of this death pathway, by means of over-expression of survival genes such as bcl-2, results in improved cellular robustness and antibody productivity during batch culture. In the present study, the influence of bcl-2 expression on hybridoma productivity in two high density perfusion bioreactor systems was investigated. In the first system, a fixed-bed reactor, the DNA content in the spent medium was 25% higher in the control (TB/C3-pEF) culture than that found in the bcl-2 transfected (TB/C3-bcl2) cultures at all perfusion rates. This is indicative of a higher level of cell death in the control cell line. The average antibody concentration for the TB/C3-pEF cell line was 14.9 mg L-1 at perfusion rates of 2.6 and 5.2 d-1. However, for the TB/C3-bcl2 cell line it was 33 mg L-1 at dilution rates of 2 and 4 d-1. A substantial increase in antibody concentration was also found in the Integra Tecnomouse hollow fibre reactor. The antibody titre in the TB/C3-bcl2 cassette was nearly 100% higher than that in the TB/C3-pEF cassette during the cultivation period which lasted 6 weeks. Clearly, these results demonstrate the positive impact of bcl-2 over-expression on production of antibody in hybridoma perfusion cultures.
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  • 56
    ISSN: 1573-0778
    Keywords: antibody productivity ; apoptosis ; BAG-1 ; Bcl-2 ; cell survival ; hybridoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Human bcl-2 and bag-1 DNA were introduced into mouse hybridoma 2E3- O cells and expressed. The expression of bcl-2 in BCMGneo-bcl2 transfectants was confirmed by ELISA and that of bag-1 in pZeo-bag1 was confirmed by western blotting. In batch cultures, the over-expression of bcl-2 prolonged the culture period by 2 days and co-expression of bcl-2 and bag-1 prolonged the culture period by 3 days. The delayed increase in the dead cell number in culture of the bcl-2 and bag-1 cotransfectant indicated the additional antiapoptosis effect of bcl-2 and bag-1 cotransfection in comparison with the bcl-2 only transfection. The bcl-2 transfectants (2E3O-Bcl2) produced antibody twofold per batch culture in comparison with 2E3-O cells transfected with BCMGSneo (2E3O-Mock). Enhancement of this MoAb production was due to the improved survival of the cells and was not due to stimulation of antibody production rate per cell by Bcl-2 expression. And the bcl-2 and bag-1 co-transfectant (2E3O-Bcl2-BAG1) produced antibody approximately fourfold of 2E3O-Mock per batch culture. Enhancement of this MoAb production was due to the improved survival of the cells and was partly due to stimulation of MoAb production rate per cell in the non-growing phase by the cotransfection. The method to engineer hybridoma cells genetically with bcl-2 and bag-1 for increasing viability and productivity would be widely applied for improving antibody productivity of hybridoma cultures.
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  • 57
    ISSN: 1573-0778
    Keywords: annexin V ; Apo-2 ligand ; apoptosis ; Cytostar-T® scintillating microplates ; flow cytometry ; lymphotoxin (LT)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The translocation of phospholipids across the plasma membrane has been widely documented as one of the earliest measurable biochemical events of apoptosis. Using fluorescently labelled annexin V, which preferentially binds phosphatidylserine (PS) in the presence of Ca2+, the externalization of PS can be measured and apoptosis quantified using flow cytometry. Conventional detection methods utilizing annexin V, while faster than in situ DNA end-labelling or DNA laddering, require extensive sample preparation which may compromise samples and makes rapid, high volume screening prohibitive. This paper describes a novel assay for the measurement of apoptosis based upon binding of radiolabelled annexin V to apoptotic cells attached to the growth surface of a 96-well scintillating microplate (Cytostar-T®). We compared measurements of apoptosis made by flow cytometry to those obtained with the scintillating microplate in three model systems, treatment of: mouse connective tissue (L-M) cells with lymphotoxin (LT), human lung carcinoma (H460) cells with Apo-2 ligand and human umbilical vein endothelial (HUVE) cells with staurosporine. In this assay, we compare both direct and indirect labelling methods by utilizing either iodinated annexin V or biotinylated annexin V/[35S] streptavidin to radiolabel apoptotic cells. The signal detected is a direct consequence of the binding of annexin V to externalized PS on apoptotic cells and the proximity of the label to the base of the plate. Using this method, separation of bound and unbound radiolabel signal occurs directly within the well resulting in a sensitive assay that requires minimal manipulation and can accomodate a large number of samples.
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  • 58
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    Cardiovascular drugs and therapy 13 (1999), S. 289-294 
    ISSN: 1573-7241
    Keywords: heart failure ; apoptosis ; protein kinases ; caspases ; DNA damage ; cardiomyocytes ; β-blocks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Apoptosis as defined by contemporary science describes a form of cell death that involves discrete genetic and molecular programs, de novo protein expression and unique cellular phenotype. Evidence for the existence of apoptosis in the human heart has been reported in various cardiac diseases, including ischemic and non-ischemic heart failure, myocardial infarction and arrhythmias. Among the most potent stimuli that elicit cardiomyocyte apoptosis are: oxygen radicals (including NO), cytokines, (FAS/TNFα family of cytokines) and growth factors/energy deprivation. Several complex signal transduction pathways have been implicated in execution of cardiomyocyte apoptosis, including: Fas/TNFα receptors signaling, stress or mitogen activated protein kinases (SAPK/MAPK), sphingolipids metabolites (ceramide), G-protein coupled receptor (GPCR) signaling (Gαi, Gαq) and NFkB activation. Apoptosis of cardiac myocytes may contribute to progressive pump-failure, arrhythmias and cardiac remodeling. The recognition of numerous molecular targets associated with cardiomyocyte apoptosis that are amenable for pharmacologic manipulation, may provide novel therapeutic strategies for diverse cardiac ailments, as recently suggested by pharmacologic studies in experimental animals.
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  • 59
    ISSN: 1573-7373
    Keywords: apoptosis ; cell death ; C6 glioma ; nerve growth factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nerve growth factor (NGF) plays an important physiological role in differentiation and survival of various types of neurons. Glial cells and glial tumor cells synthesize multiple neurotrophic factors including NGF and secrete them into the surrounding environment; however, the mechanisms of NGF and the significance of NGF receptors have not been studied in detail. The C6 glioma cell line can synthesize NGF, respond to exogenous application of NGF and stimulate the expression of NGF receptor in an autocrine manner. In order to determine the significance of such an NGF autocrine system, the effects of exposure to exogenous NGF and deprivation of endogenous NGF were examined in a C6 glioma cell line in vitro. Exogenous NGF significantly inhibited maintenance of the cell number and thymidine incorporation. Morphological changes, including the formation of growth cones, outgrowth of processes and cellular hypertrophy, were observed, concurrently, indicating that exogenous NGF stimulated differentiation and thereby inhibited proliferation of the cells. Deprivation of endogenous NGF with anti-NGF antibody elicited a rapid decrease in cell number and thymidine incorporation, and led almost all of the cells to death within 8 days. The protein synthesis inhibitor, cycloheximide, strongly inhibited the death of NGF-deprived cells, suggesting the involvement of an active process requiring synthesis of suicide proteins. These findings imply that the NGF autocrine system plays a significant role in regulating the differentiation and survival of C6 glioma cells, similarly to neuronal cells.
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  • 60
    ISSN: 1573-7373
    Keywords: glutamate ; glioblastoma ; apoptosis ; Bcl-2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Glutamate has been shown to function as a toxic agent in neuronal and glial cells, as well as an excitatory neurotransmitter throughout the central nervous system. In the present study, we examined the effect of increasing glutamate concentration on the induction of apoptosis in the two human glioblastoma cell lines GB-4 and GB-12. Glutamate exposure caused cell death of GB-4 and GB-12 in a dose-dependent manner. The cells were found to die via apoptosis in response to glutamate based on the following criteria: propidium iodide (PI) staining, H–E staining, electron microscopic analysis, and the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. The glutamate-induced apoptosis appears to involve the modulation of Bcl-2 family gene products such as Bcl-2, Bcl-xL, and Bax-α. Both Bcl-2 and Bcl-xL were down-regulated by glutamate at 24 h and further at 48 h. The apoptosis-promoting product p21 Bax-α was also down-regulated in GB-12 but slightly up-regulated in GB-4, accompanied by generation of variant form of p18 Bax-α in both cell lines. These findings suggest that glutamate toxicity results in cellular death via an apoptotic mechanism which appears to involve the Bcl-2/Bax-α molecular complex.
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  • 61
    ISSN: 1573-7365
    Keywords: Cerebral ischemia ; focal ischemia ; mutant mice ; bcl-2 ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neuronal death after brain ischemia is mainly due to necrosis but there is also evidence for involvement of apoptosis. To test the importance of apoptosis, we investigated the effect of targeted disruption of the apoptosis-suppressive gene bcl-2 on the severity of ischemic brain injury. Transient focal ischemia for 1 hour was induced by occlusion of the middle cerebral artery in homozygous (n=7) and heterozygous (n = 6) bcl-2 knockout mice as well as in their wildtype littermates (n=5). Bcl-2 ablation did not influence cerebral blood flow but it significantly increased infarct size and neurological deficit score at 1 day after reperfusion in a gene-dose dependent manner. The exacerbation of tissue damage in the absence of Bcl-2 underscores the importance of apoptotic pathways for the manifestation of ischemic injury after transient vascular occlusion.
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  • 62
    ISSN: 1573-7373
    Keywords: glioma ; immunohistochemistry ; MIB-1 ; apoptosis ; TUNEL
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract With the introduction of new (immuno-)histochemical techniques it is now possible to assess rates of proliferation and apoptosis in brain gliomas using archival paraffin embedded material. As proliferation and apoptosis are related to tumour growth rate quantification of these processes has prognostic value and is related to tumour grading. In this study we assessed the proliferation rate by measuring the Ki-67 labelling index using the MIB-1 antibody (MIB-LI) and the apoptotic rate using the in situ labelling of DNA strand breaks with TUNEL (TUNEL-LI) in 315 supratentorial gliomas. MIB-LI and TUNEL-LI in astrocytomas (A) where significantly lower compared to anaplastic astrocytomas (AA), glioblastomas (GBM) and oligodendroglial tumours [oligodendrogliomas (O) and anaplastic oligodendrogliomas (AO)]. MIB-LI and TUNEL-LI were significantly lower in AA compared to GBM. In astrocytic tumours MIB-LI and TUNEL-LI appeared to be correlated. As the distinction between A and AA is of clinical value but can be difficult histomorphologically we analysed the prognostic value of MIB-LI and TUNEL-LI in gliomas with particular emphasis on A and AA. MIB-LI below 10% was of prognostic value in A and AA, O and AO but not in GBM on univariate survival analysis. TUNEL-LI was of no prognostic value. With multivariate survival analysis MIB-LI lost prognostic significance in O and AO. Astrocytomas with a gemistocytic component (AG) are similar to A with respect to survival and MIB-LI and TUNEL-LI. MIB-LI is of independent prognostic value in A and AA. Assessment of MIB-LI in A and AA can be used as an aid in distinguishing A and AA.
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  • 63
    ISSN: 1573-7373
    Keywords: apoptosis ; astrocytoma ; glioma ; growth inhibition ; protein kinase C ; signal transduction ; UCN-01
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recent studies in our laboratory have shown that UCN-01 (7-hydroxystaurosporine), which is a derivative of the non-selective protein kinase inhibitor staurosporine that exhibits relative selectivity for protein kinase C (PKC), is a potent inhibitor of glioma growth in in vitro and in vivo models. This agent exhibits both cytotoxic and cytostatic effects, depending on the time period of drug exposure. In the present study, we examined whether UCN-01-induced cytotoxicity correlated with the induction of apoptosis, and characterized further the time course of this process as a prelude to application of UCN-01 in clinical trials. We first demonstrated that the cytotoxic effects of UCN-01 were associated with the induction of morphological features of apoptosis. Secondly. we identified electrophoretic features of apoptosis semiquantitatively at a series of time points using field inversion gel electrophoresis. These studies showed a peak in the induction of high-molecular-weight DNA fragmentation after 3–6 days of drug treatment. Thirdly, we measured the percentage of cells undergoing apoptosis at various time points using a terminal transferase-catalyzed in situ end-labeling technique, which confirmed a time- and concentration-dependent increase in apoptotic cell numbers. This correlated with a progressive decrease in the percentage of cells that were viable as assessed by trypan blue exclusion. Cell killing peaked within 2–4 days after beginning UCN-01 treatment, but continued at a lower level in the ensuing days. Taken together, these studies demonstrated that extended periods of exposure to UCN-01 are needed for optimal manifestation of cytotoxic effects against glioma cells, a factor that must be taken into consideration in the design of future clinical trials with this agent for malignant gliomas.
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  • 64
    ISSN: 1573-7373
    Keywords: germinoma ; spontaneous regression ; multiple intracranial ; germ cell tumor ; immunological mechanism ; apoptosis ; MIB-1 index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of multiple intracranial germ cell tumor in which a pineal tumor regressed spontaneously after resection of the cerebellar mass is reported. Immunohistochemical staining of the cerebellar mass showed that most of the infiltrating lymphocytes were positive for CD3 and CD8. The anti-Ki-67 monoclonal antibody MIB-1 staining of the resected tumor revealed a high MIB-1 positivity ratio (36.1%) among the large tumor cells, and TUNEL staining demonstrated that positivity in up to 6% of the tumor cells. Possible mechanisms responsible for this spontaneous regression including immunological responses and apoptosis induced by T lymphocytes are discussed.
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  • 65
    ISSN: 1573-7373
    Keywords: apoptosis ; cell cycle ; cell death ; medulloblastoma ; T cells ; tumour necrosis factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied the effect of the treatment of a medulloblastoma cell line by human T cells derived soluble factors. Medulloblastoma is one of the more common aggressive solid neoplasms in children for which there is no adequate therapy. Cell lines established from such tumours may be helpful to test the effect of various molecules on cell proliferation. Previous studies have suggested that T cell-derived factors may be toxic for the medulloblastoma cell line Dev. Cytokines were thought to mediate this effect. In this paper, we described changes in morphology, survival and cell cycle induced in Dev cells cocultured with human T cell lines chronically infected with a retrovirus (HTLV-I) and known to secrete high level of cytokines TNFα, IL1α and IL6. Such cocultures resulted in the death of a part of Dev cells and in decreased proliferation of surviving cells, associated with morphological changes and increase in vimentin expression. Treatment with conditioned medium from infected Dev cells, containing virus induced cytokines, triggered the same effect. Reduction of these effects by TNFα deprivation of conditioned medium suggested that this cytokine may be implicated. Direct treatment of Dev cells with recombinant cytokines indicated that TNFα, but not IL1 or IL6, is associated with Dev cell alterations. TNFα was shown to induce the death of Dev cells by an apoptotic pathway. Furthermore, TNFα had a bimodal effect on the cell cycle of surviving Dev cells. These differential effects of such cytokines on medulloblastoma cells could be therefore of interest for immunotherapy of these tumours.
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  • 66
    ISSN: 1573-7373
    Keywords: adenoviral gene transfer ; p53 ; apoptosis ; experimental malignant gliomas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Adenoviral-mediated gene transfer for the treatment of experimental intrinsic malignant brain neoplasms holds promise. The role, however, of intracellular, adenoviral-mediated p53 expression to inhibit growth of experimental human intracranial malignant gliomas remains largely unexplored. Using the AdCMV.p53 vector we measured the in vitro expression of p53 and the resultant effect upon U251 human malignant glioma cellular proliferation. We further measured the survival of nude mice after intracranial injection of the infected vs. control U251 cells. The growth of the infected U251 cells was inhibited when compared to both the uninfected cells and cells infected with the control vector (AdCMV.Null). Agarose gel electrophoresis confirmed the AdCMV.p53-dependent cellular apoptosis. Nude mice having intracranial injections of the U251 cells infected with the control (AdCMV.Null) vector showed diminished survival. In contrast, mice having intracranial injections of the cells infected with the AdCMV.p53 vector showed 100% survivorship measured 100 days after treatment. Gene therapy via the AdCMV.p53 viral vector holds promise for the clinical treatment of human malignant gliomas.
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  • 67
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    Journal of neuro-oncology 41 (1999), S. 159-166 
    ISSN: 1573-7373
    Keywords: neuroblastoma ; chemotherapy ; apoptosis ; dopamine receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract While neuroscientists are often involved in the assessment and care of patients with central nervous system tumors, they are only rarely involved in the case of peripheral nervous system neoplasia. Neuroblastoma is a childhood tumor of the primitive sympathetic nervous system. It is at once one of the most common and one of the most deadly tumors of childhood. The prognosis for children with this tumor has not changed in the past two decades. Clearly, a fresh approach to neuroblastoma is needed. The neuroscientist has much to add to our understanding and treatment of neuroblastoma and its sequelae. Conversely, neuroblastoma has much to teach us regarding the normal development of the neural crest and the aberrant loss of neurons in this lineage. A neuroscientist's approach to neuroblastoma, its biology and clinical features, is presented herein.
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  • 68
    ISSN: 1573-7373
    Keywords: apoptosis ; chemotherapy ; human cell lines ; lovastatin ; medulloblastoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Medulloblastoma is a malignant paediatric central nervous system tumor with a poor prognosis, stimulating the evaluation of improved treatment strategies. Lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, is currently used to treat patients with hypercholesterolemia. This compound also inhibits the production of non-steroidal mevalonate derivatives that are implicated in the control of cellular proliferation, and can induce cell-cycle arrest in vitro. We recently showed that lovastatin inhibited growth and promoted apoptosis of neuroblastoma, the peripheral nervous system ‘cousin’ of medulloblastoma. Therefore the potential of lovastatin as a possible anticancer drug against medulloblastoma was evaluated in vitro. Four medulloblastoma cell lines, Daoy, UW228, D341 Med and D283 Med, were treated with 1–40 µM of lovastatin in vitro. Analysis of cell morphologic changes, cell viability, DNA fragmentation and flow cytometry in all four cell lines showed growth inhibition and induction of apoptosis with lovastatin treatment. As little as 10 µM of lovastatin was sufficient to cause a marked reduction in cell numbers, and more than 20 µM of lovastatin induced 〉90% cells to undergo apoptosis, after intervals ranging between 36 and 96 h, depending on the cell line. Lovastatin induced apoptosis in these cell lines was concomitant with cell cycle arrest in G1. The attached cell lines UW228 and Daoy were more sensitive to lovastatin than D283 Med and D341 Med. Daoy cells which survived several cycles of lovastatin treatment could still be induced to undergo apoptosis after longer treatment times. The efficient induction of apoptosis by lovastatin favours this drug as a potential new avenue of therapeutic intervention for medulloablastoma.
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  • 69
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    Journal of neuro-oncology 43 (1999), S. 237-239 
    ISSN: 1573-7373
    Keywords: primary CNS lymphoma ; glucocorticoids ; cerebral edema ; apoptosis ; bcl-2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Glucocorticoid therapy may result in the rapid resolution of cerebral mass lesions in patients with primary CNS lymphoma. Since glucocorticoids will obscure the histological diagnosis of primary CNS lymphoma upon biopsy, steroids should be withheld if primary CNS lymphoma is a likely diagnosis by neuroradiological criteria. The lympholytic effect of glucocorticoids is mediated by cytoplasmic steroid receptors which are translocated to the nucleus and signal apoptosis. Glucocorticoid-induced apoptosis of lymphoid cells does not require wild-type p53 activity, seems not to depend on caspase activation, but is attenuated by the bcl-2 protooncogene product. Long-term glucocorticoid therapy of primary CNS lymphoma is not recommended because relapse is probably inevitable and because of the prominent side effects of long-term glucocorticoid treatment. Further, long-term glucocorticoid treatment is contraindicated in immunocompromised patients with primary CNS lymphoma.
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  • 70
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    Journal of neurocytology 28 (1999), S. 149-159 
    ISSN: 1573-7381
    Keywords: prion disease ; transmissible spongiform encephalopathy ; cell culture ; toxicity ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aetiological agent of prion disease is proposed to be an aberrant isoform of the cell surface glycoprotein known as the prion protein (PrPc). This pathological isoform (PrPSc) is abnormally deposited in the extracellular space of diseased CNS. Neurodegeneration in these disease has been shown to be associated with accumulation of PrPSc in affected tissue. To investigate the possible uptake mechanisms that may be required for PrPSc-induced neurodegeneration we studied the cellular trafficking of the neurotoxic fragment, PrP106-126. We were able to detect, by fluorescence microscopy, PrP106-126 inclusions in murine neurones, astrocytes and microglia in vitro. These inclusions were abundant after 24 hour exposure and still present 48h post-exposure. Shorter exposure times yielded only occasional cells with inclusions. Large extracellular aggregates of PrP106-126 could also be detected, which appeared in a time dependent manner. The appearance of inclusions or aggregates was not dependent on PrPc expression as determined by exposure of peptides from PrP-null mice. Using transmission electron microscopy and gold particle detection, positively labelled osmiophilic inclusions of peptide could be detected in the cytoplasm of exposed cells. These results demonstrate that cultured cells are capable of sequestering PrP106-126 and may indicate uptake pathways for PrPSc in various cell types. Toxicity of PrP106-126 may thus be mediated via a sequestration pathway that is not effective for this peptide in PrP-null cells.
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  • 71
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    Bioscience reports 19 (1999), S. 345-354 
    ISSN: 1573-4935
    Keywords: Glycolipid ; apoptosis ; intracellular traffic ; multidrug resistance ; ovarian carcinoma ; astrocytoma ; post transplant lymphoproliferative disease ; bone marrow purging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Verotoxin (VT) is involved in the etiology of both hemorrhagic colitis and the hemolytic uremic syndrome which are microvasculopathies of the colon and pediatric renal glomerulus respectively. Thus, VT can be considered a vasotoxin. Cell sensitivity in vitro varies according to the receptor glycolipid (globotriaosyl ceramide-Gb3) expression and also to intracellular trafficking of the receptor/toxin complex, such that in highly sensitive cells, the toxin is targeted to the endoplasmic reticulum and nuclear envelope. Such cells include tumor cells which have become drug resistant. Thus Gb3 is upregulated in certain tumors and when such tumor cells become drug resistant, their sensitivity to verotoxin increases. This may be due to a direct role of the MDR1 drug efflux pump in glycolipid biosynthesis. In addition to the tumor tissue, the toxin receptor may also be expressed in the tumor neovasculature suggesting that activated endothelial cells may be verotoxin sensitive. Thus VT may have both a direct and indirect antineoplastic potential. VT has proved highly effective in a xenograft cancer model and the possible therapeutic use of VT is discussed.
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  • 72
    ISSN: 1573-4935
    Keywords: ceramide glycanase ; cancer cells ; glycosphingolipid ; sphingosine ; ceramide ; apoptosis ; PPMP ; PDMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ceramide glycanase (CGase) activities have been detected in different human tumor cells (colon, carcinoma Colo-205; neuroblastoma, IMR-32; breast cancer lines, SKBr3 and MCF7). However, the level of enzymatic activity is lower in these cells compared to that present in other mammalian tissues reported before (Basu, M., Kelly, P., Girzadas, M. A., Li, Z., and Basu, S. Methods Enzymol. (in press)). The majority of CGase activity was found in the 100,000g soluble supernatant fraction isolated from all these cell lines and tissues. Using the soluble enzyme, the requirement for optimum CGase activity was found to be consistent with previous observations found for rat and rabbit tissues (Basu, M., Dastgheib, S., Girzadas, M. A., O'Donnell, P. H., Westervelt, C. W., Li, Z., Inokuchi, J. I., and Basu, S. (1998) Acta Pol. Biochim. 42:327). The CGase activities from both Colo-205 and IMR-32 cells are optimum at a protein to detergent ratio of one. All the mammalian CGases, including human cancer cells, show an optimum pH between 5.5 and 5.8 in sodium acetate buffer. The CGase activities from cancer cells are found to be cation-independent; however, mercury, zinc, and copper ions seem to inhibit the enzyme activity substantially in both tumor cells lines. The mercury ion inhibition of CGase activities from all different sources indicates a possible structural homology in the CGase proteins. Radiolabeled substrates, labeled at the sphingosine double bond or at the 3-position of sphingosine without modifying double bond of sphingosine were used in this investigation. Both were active substrates with all enzyme preparations isolated from different cancer cells (apparent Km, 500 μM for nLcOse5[3H-DT]Cer and 350 μM for GgOse4[sph-3-3H]Cer with Colo-205 enzyme). Structural analogues of ceramide and sphingosine (L-PPMP, L-PDMP, alkylamines, and Tamoxifen) inhibited cancer cell CGase activities in vitro.
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  • 73
    ISSN: 1573-7403
    Keywords: apoptosis ; corticotroph adenomas ; heat shock proteins ; p53
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The pathogenesis of corticotroph adenomas is unknown. In a recent study accumulation of p53 protein was detected by immunohistochemistry in a substantial proportion of pituitary corticotroph adenomas, and it has been suggested that it may be causally related to their development. However, other immunohistochemical studies have not confirmed the high incidence of p53 accumulation in this tumor type. Therefore, in the present study, p53 protein accumulation was re-examined in a series of 31 cases of corticotroph adenomas, using different sets of well validated anti-p53 antibodies. Furthermore, in view of the known association of p53 protein with apoptosis, and the known property of p53 to form complexes with heat shock proteins (HSPs), the relationship of p53 accumulation in corticotroph adenomas with apoptosis and HSP-70 was also investigated. Tumor samples staining positively for ACTH from patients with Cushing's disease or Nelson's syndrome were studied. Accumulation of p53 protein was tested by the standard ABC method using two different sets of clone Pab1801 and DO-7 monoclonal antibodies, applied after incubation of sections in a microwave oven. Using the DO-7 antibody, nuclear accumulation of p53 protein was detected in a total of 15 cases, with cytoplasmic staining observed in only 3 tumors. In contrast, using the Pab1801 antibody nuclear staining was observed in only 5 adenomas, with 11 adenomas demonstrating focal cytoplasmic immunoreactivity. Parallel sections of all corticotroph tumors demonstrating cytoplasmic accumulation of p53 protein were tested for the immunohistochemical presence of heat shock protein HSP-70. A striking similar distribution pattern of these two proteins was observed. Apoptosis, identified by the in situ end labeling technique, was detected in a total of 15 out of 28 corticotroph adenomas tested. Calculation of the apoptotic labeling index (ALI) by image analysis showed a significantly lower ALI in those corticotroph adenomas demonstrating nuclear p53 accumulation compared to those with no nuclear p53 immunostaining (p〈0.05). There was no significant difference in the ALI between cytoplasmic p53 positive and negative tumors. It is concluded that depending on the antibody used there is a significant variation of p53 protein detection in corticotroph adenomas. Overall, a significant proportion of corticotroph adenomas studied expressed the p53 protein, which depending on the antibody used, was located either in the nucleus and/or the cytoplasm of tumorous corticotroph cells. Cytoplasmic accumulation of p53, as shown by our colocalization studies with HSP-70, may be due to p53/HSP-70 complex formation. Although such a complex-mediated cytoplasmic exclusion of p53 has no significant effect on apoptosis, nuclear accumulation of p53 protein is associated with a significantly lower apoptotic index indicating a failure of p53 protein to exert its apoptotic action in at least a subset of this tumor type.
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  • 74
    ISSN: 1573-675X
    Keywords: Adenosine ; apoptosis ; necrosis ; physiopathological implications.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Adenosine modulates the proliferation, survival and apoptosis of many different cell types, ranging from epithelial, endothelial and smooth muscle cells, to cells of the immune and neural lineages. In this review, we critically discuss the available in vitro and in vivo data which support a role for adenosine in both development-associated apoptosis, and in diseases characterized by either pathologically increased cell death (e.g., ischemia, trauma and aging-associated neurodegeneration) or abnormally reduced spontaneous apoptosis (e.g., cancer). Particular emphasis is given to the possible role of extracellular adenosine receptors, since these may represent novel and attractive molecular targets for the pharmacological modulation of apoptosis. In some instances, adenosine-induced cell death has been demonstrated to require entry of the nucleoside inside cells; however, in many other cases, activation of specific adenosine extracellular receptors has been demonstrated. Of the four G protein-coupled adenosine receptors so far identified, the A2A and the A3 receptors have been specifically implicated in modulation of cell death. For the A3 receptor, results obtained by exposing both cardiomyocytes and brain astrocytes to graded concentrations of selective agonists suggest induction of both cell protection and cell death. Such opposite effects, which likely depend on the degree of receptor activation, may have important therapeutic implications in the pharmacological modulation of cardiac and brain ischemia. For the A2A receptor, recent intriguing data suggest a specific role in immune cell death and immunosuppression, which may be relevant to both adenosine-deaminase-immunodeficiency syndrome (a pathology characterized by accumulation of adenosine to toxic levels) and in tumors where induction of apoptosis via activation of specific extracellular receptors may be desirable. Finally, preliminary data suggest that, in a similar way to the adenosine-deaminase-immunodeficiency syndrome, the abnormal accumulation of adenosine in degenerative muscular diseases may contribute to muscle cell death. Although the role of adenosine receptors in this effect still remains to be determined, these data suggest that adenosine-induced apoptosis may also represent a novel pathogenic pathway in muscular dystrophies.
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  • 75
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    Apoptosis 4 (1999), S. 317-319 
    ISSN: 1573-675X
    Keywords: Anti-tumor therapy ; Apoptin® ; apoptosis ; Bcl-2 ; p53.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Apoptin, a protein encoded by an avian virus, induces apoptosis in various cultured human tumorigenic and/ or transformed cell lines, e.g. derived from breast and lung tumor, leukemia, lymphoma, osteosarcoma melanoma, cholangiocarcinoma, and hepatoma. In such cells, Apoptin induces p53-independent apoptosis, and the proto-oncogene Bcl-2 can accelerate this effect. The latter is surprising for, in general, Bcl-2 is known to inhibit e.g., p53-induced apoptosis. On the other hand, in normal non-transformed human cells, Apoptin is unable to induce apoptosis, even when Bcl-2 is over-expressed. In animal models Apoptin-induced apoptosis appears to be a safe and efficient anti-tumor agent. These data, in continuation with the observations that Apoptin is specifically stimulated by Bcl-2 in tumor cells, does not need p53, and is not inhibited by Bcr-Abl in these cells, imply that Apoptin is a potential anti-tumor therapy.
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  • 76
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    Apoptosis 4 (1999), S. 229-234 
    ISSN: 1573-675X
    Keywords: Adenovirus ; apoptosis ; Bcl-2 ; p53 ; Rb ; ventricular myocytes.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Apoptosis or programmed cell death is an important physiologic event crucial for the selective removal of damaged or unwanted cells from body tissues. In the cardiovascular system, apoptosis has been observed in the vasculature and myocardium. Untimely or inappropriate myocardial cell loss through an apoptotic process may contribute to ventricular remodeling and the ultimate demise of ventricular function following injury. Therapeutic interventions designed to modulate or prevent myocardial apoptotic cell loss may therefore prove beneficial in maintaining cardiac function. Incite into the molecular mechanisms that govern apoptosis in mammalian cells has led to the identification of several key factors that promote or prevent the apoptotic process. In this report, we discuss putative regulators of cardiac cell apoptosis with specific reference to the tumor suppressor proteins, p53 and Rb. The interplay between these factors, as well as the anti-apoptotic molecules related to the Bcl-2 the family are discussed in the context of the heart under normal and disease conditions.
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  • 77
    ISSN: 1573-675X
    Keywords: Anti-microtubule agents ; apoptosis ; doxorubicin ; neuroblastoma ; tau ; taxoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Paclitaxel and docetaxel are potent anti-microtubule and antimitotic agents that induce apoptosis in bone marrow-derived cells and epithelial cells. This study examined apoptosis induced by anti-microtubule agents in the neuroblastoma SK-N-SH cell line with a special focus on tau protein which is one of the main Microtubule-Associated- Proteins (MAPs) in neuronal cells. In time, treatment with 1 μM paclitaxel successively induced formation of bundles, then pseudo-asters concomitantly with mitotic block and phosphorylation of bcl-2 (48 h), then phosphorylation of tau and externalization of phosphatidylserine at the early phase of apoptosis (72 h) and finally DNA fragmentation (96 h). Similar results were obtained with 0.5 μM vinorelbine. Paclitaxel induced a lower increase in tau phosphorylation in differentiated SK-N-SH/RA+ cells which are less sensitive to apoptosis. Moreover, doxorubicin whose mechanism of action is independent of microtubules also induced immunostaining of tau at 72 h treatment. In conclusion, our results on neuroblastoma cells show that overexpression of hyperphosphorylated tau is involved in the apoptotic process induced by anti-microtubule agents and may be extended to others cytostatic drugs. Thus, tau protein may play a role in the cellular events observed in neuroblastoma cells undergoing apoptosis.
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  • 78
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    Apoptosis 4 (1999), S. 71-80 
    ISSN: 1573-675X
    Keywords: abl ; apoptosis ; interleukin-3 ; oncogenes ; ras.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Growth factors promote cell survival and proliferation. Homeostasis is maintained by programmed cell death which occurs when the growth stimulus is withdrawn, in response to negative growth regulators such as interferons, TNF-α and CD95 ligand, or following differentiation. Although acutely-transforming oncogenes often overcome the need for growth factors, growth regulatory cytokines can influence proliferative responses of transformed cells. In this study we investigated the effects of IL-3 on the proliferative responses of parental bone marrow-derived 32D cells and cells transformed with ras and abl oncogenes. We show that treatment of ras-transformed 32D cells with IL-3 reduced proliferative responses and decreased colony-forming ability. These effects were exacerbated in the absence of serum and associated with inhibition of tyrosine kinase activity, down-regulation of RAS and MYC expression, and induction of apoptosis as indicated by DNA fragmentation. In contrast, treatment of parental 32D cells with IL-3, which is obligatory for cell survival and proliferation, increased tyrosine kinase activity, upregulated MYC and RAS expression and maintained DNA integrity. With abl-transformed cells, proliferation and colony-forming ability were also inhibited by IL-3. Tyrosine kinase activity and MYC expression were reduced, but early apoptosis was not evident. Calcium uptake however, was stimulated by IL-3 in both parental and oncogene-transformed cells. These results suggest that threshold levels of tyrosine kinase activity are necessary for cell survival and proliferation and that with ras-transformed cells, IL-3 treatment may result in this threshold being breached. We conclude that in some situations, growth-promoting cytokines can inhibit proliferation of transformed cells and induce cell death by apoptosis.
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  • 79
    ISSN: 1573-675X
    Keywords: ameloblasts ; amelogenesis ; apoptosis ; insulin-like growth factor.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Enamel-producing cells (ameloblasts) pass through several phenotypic and functional stages during enamel formation. In the transition between secretory and maturation stages, about one quarter of the ameloblasts suddenly undergo apoptosis. We have studied this phenomenon using the continuously erupting rat incisor model. A special feature of this model is that all stages of ameloblast differentiation are presented within a single longitudinal section of the developing tooth. This permits investigation of the temporal sequence of gene and growth factor receptor expression during ameloblast differentiation and apoptosis. We describe the light and electron microscopic morphology of ameloblast apoptosis and the pattern of insulin-like growth factor-1 receptor expression by ameloblasts in the continuously erupting rat incisor model. In the developing rat incisor, ameloblast apoptosis is associated with downregulated expression of the insulin-like growth factor-1 receptor. These data are consistent with the hypothesis that ameloblasts are “hard wired” for apoptosis and that insulin-like growth factor-1 receptor expression is required to block the default apoptotic pathway. Possible mechanisms of insulin-like growth factor-1 inhibition of ameloblast apoptosis are presented. The rat incisor model may be useful in studies of physiological apoptosis as it presents apoptosis in a predictable pattern in adult tissues.
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  • 80
    ISSN: 1573-675X
    Keywords: AKR lymphoma malignancy variants ; apoptosis ; apoptosis-related gene expression ; tumor progression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Resistance to apoptosis may be related to tumor progression, due to the implications it might have on both tumor mass and genetic instability. We compared the tendency to spontaneous apoptosis and the proliferative capacity of metastatic growths of several AKR lymphoma variants (TAU-45, TAU-47, TAU-44, TAU-33, TAU-42 and TAU-46, in the order of increasing metastatic potential). We further compared the expression of several apoptosis-related genes. Cell proliferative capacity did not appear to determine malignant behavior since, on the whole, a decrease in S + G2M fraction was observed with increasing malignancy. Sensitivity to apoptotic cell death decreased with increasing malignancy when comparing the TAU-45, TAU-47, TAU-44 and TAU-33 variants, suggesting a role of reduced apoptosis in this T-cell lymphoma. An increase in Bcl-2 content with increasing aggressiveness among these variants, implicates this protein in this tumor progression-related resistance to apoptosis. However, the two variants of highest malignancy, TAU-42 and TAU-46, did not follow the same trend, since they displayed a relatively high content in apoptotic cells and a low Bcl-2 content. Fas receptor expression did not correlate with tendency to apoptosis, indicating that malignant behavior in the AKR lymphoma does not depend on CD95/Fas/APO1 downregulation. Overexpression of p53 was observed only in one of the variants of lowest malignancy.
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  • 81
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    Apoptosis 4 (1999), S. 419-427 
    ISSN: 1573-675X
    Keywords: Anti-oxidant defence ; apoptosis ; ether lipids ; glutathione ; ionising radiation ; stress.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have investigated the mechanisms of induction of apoptosis by the antineoplastic ether lipid ET-18-OCH3 (ALP) in sensitive S49wt mouse lymphoma cells and ALP-resistant S49ar variants, both with wild-type p53, and in related L1210 cells with mutated p53. Ether lipid-resistant S49ar cells were cross-resistant to extracellular stress factors (cold shock, heat shock, H2O2, dimethylsulfoxide) and to radiation-induced apoptosis but not to physiological apoptotic signals (dexamethasone, growth factor deprivation, thapsigargin, C2-ceramide) and expressed similar levels of the apoptosis-regulating proteins Bcl-2, Bcl-X, Bax, Bad and Bak as did the parent S49wt cells. The uptake of [3H]-ALP was strongly reduced in the stress-resistant cells but this was not associated with significant differences in membrane cholesterol:phospholipid content nor in membrane microviscosity. In S49ar cells the activity of the antioxidant enzyme glutathione peroxidase (GSH-Px) was increased 4-fold and depletion of glutathione with the drug L-buthionine-S-R-sulfoximine (L-BSO) lowered the resistance of S49ar cells to ALP, stress factors and ionising radiation. The results indicate that ether lipids induce apoptosis by imposing a special form of physico-chemical stress, mediated by reactive oxygen species but independent of p53 status. The capacity of glutathione-dependent anti-oxidant defence appeared an important and shared determinant of the sensitivity to ether lipids, several types of extracellular stress and ionising radiation.
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  • 82
    ISSN: 1573-675X
    Keywords: Annexin V ; apoptosis ; flow cytometry ; intracellular Ca2+ ; intracellular pH ; mitochondrial membrane potential.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The sequential occurrence of plasma and mitochondrial membrane alterations, intra-cellular pH shifts and changes in intracellular Ca2+ concentration after induction of cell death was monitored by flow cytometry in Jurkat and HSB2-cells. Cell death was induced by treatment with anti-Fas antibodies or by irradiation. Phosphatidylserine (PS) exposure and plasma membrane integrity were measured with FITC-Annexin V adhesion and by Propidium Iodide exclusion. Transition of the mitochondrial membrane potential was monitored by the occurrence of decay of DiOC6 fluorescence. Intracellular pH shifts were monitored by changes in the ratio of fluorescence at 575 nm and at 635 nm of SNARF-1-AM. Fluctuations in intracellular Ca2+ concentration were established by changes in Fura red quenching. The Jurkat cells were sensitive to anti-Fas treatment, while HSB-2 cells were not. HSB-2 cells appeared more sensitive to radiation damage than Jurkat cells. In all experiments the transition of mitochondrial membrane potential occurred first, almost immediately followed by PS exposure. Fluctuations in intracellular Ca2+ concentration occurred later and were less outspoken. A decrease in intracellular pH occurred not earlier than 24 hours after anti-Fas treatment. Chelation of intracellular Ca2+ concentration with BAPTA-AM had no effect on the time sequence of cell death related events.
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  • 83
    ISSN: 1573-904X
    Keywords: MAPK ; caspases ; chemopreventive agents ; phase II drug metabolizing enzymes ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In therapeutic response to drugs, the plasma concentration range leads to the establishment of a safe and effective dosage regimen. Our hypothesis is that by studying drug concentration-dependent effect on signal transduction mechanisms, a better understanding of the beneficial pharmacodynamic and adverse toxicodynamic responses elicited by the drug may be achieved. Using two classes of chemopreventive compounds (phenolic antioxidants and isothiocyanates), we illustrate the potential utility of two signal transduction pathways elicited by these agents to predict the pharmacodynamic effect (induction of Phase II drug metabolizing enzymes) and the potential toxicodynamic response (stimulation of caspase activity and cytotoxic cell death). At lower concentration, phenolic antioxidants and isothiocyanates activate mitogen-activated protein kinase (MAPK; extracellular signal-regulated protein kinase 2, ERK2; and c-Jun N-terminal kinase 1, JNK1) in a concentration-and time-dependent manner. The activation of MAPK by these compounds may lead to the induction of cell survival/protection genes such as c-jun, c-fos, or Phase II drug metabolizing enzymes. However, at higher concentrations, these agents activate another signaling molecule, ICE/Ced3 cysteine protease enzymes (caspases) leading to apoptotic cell death. The activation of these pathways may dictate the fate of the cells/tissues upon exposure to drugs or chemicals. At lower concentrations, these compounds activate MAPK leading to the induction of Phase II genes, which may protect the cells/tissues against toxic insults and therefore may enhance cell survival. On the other hand, at higher concentrations, these agents may activate the caspases, which may lead to apoptotic cell death, and have toxicity. Understanding the activation of these and other signal transduction events elicited by various drugs and chemicals may yield insights into the regulation of gene expression of drug metabolizing enzymes and cytotoxicity. Thus, the study of signaling events in cell survival (hemeostasis) and cell death (cytotoxicity) may have practical application during pharmaceutical drug development.
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  • 84
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    Plant growth regulation 27 (1999), S. 119-123 
    ISSN: 1573-5087
    Keywords: apoptosis ; carrot protoplast ; DNA ladder ; ethrel ; ethylene ; nucleus condensation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In recent years, apoptosis has been reported to exist in plants during normal development and in response to stress. However, little is known about the relation of hormones to this form of programmed cell death. Here, we report examination of characteristics of apoptosis in carrot protoplasts induced by ethylene evolved from ethrel (2-chloroethylphosphonic acid). Nucleus condensation and DNA ladders were observed, and neutral comet assay, which detects DNA cleavage, also provided evidence that ethrel treatment resulted in nuclear DNA fragmentation. Strikingly, a close correlation between the incidence of DNA comets and the percentage of apoptotic protoplasts was shown in ethrel-treated carrot protoplasts. In conclusion, this study demonstrated that ethylene is an active inducer of apoptosis in carrot protoplasts, and that ethylene-induced plant cell death showed characteristics similar to those of apoptosis in animals.
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  • 85
    ISSN: 1573-6903
    Keywords: Ethanol ; apoptosis ; gangliosides ; LIGA20 ; cerebellar granule cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ethanol significantly enhances cell death of differentiated rat cerebellar granule neurons on culture in a serum-free medium containing a depolarizing concentration of KCl (25 mM), 5 μM MK-801 (an NMDA receptor antagonist), and 20–200 mM ethanol for 1–4 days. Cell death augmented by ethanol was concentration- and time-dependent with neurons displaying hallmark apoptotic morphology and DNA fragmentation that correlated with the activation of cytosolic caspase-3. Inclusion of 5 μM MK-801 or 100 μM glycine in culture media did not alter rates of cell death indicating ethanol toxicity is mediated via an NMDA receptor-independent pathway. Preincubation with 50 μM gangliosides GM1, GD1a, GD1b or GT1b for 2 h, or preincubation with 10 μM LIGA20 (a semisynthetic GM1 with N-dichloroacetylsphingosine) for 10 min, attenuated caspase-3 activity and ethanol-induced cell death. Data show native gangliosides and a synthetic derivative are potently neuroprotective in this model of ethanol toxicity, and potentially serve as useful probes to further unravel the mechanisms relevant to neuronal apoptosis.
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  • 86
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    Journal of bioenergetics and biomembranes 31 (1999), S. 291-304 
    ISSN: 1573-6881
    Keywords: Cell death ; aging ; necrosis ; apoptosis ; mitochondria ; oxidative phosphorylation ; electron transport chain ; ATP synthase ; cytochrome c ; mitochondrial DNA ; reactive oxygen species (ROS)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Traditionally, mitochondria have been viewed as the “powerhouse” of the cell, i.e., the site of theoxidative phosphorylation machinery involved in ATP production. Consequently, much of theresearch conducted on mitochondria over the past 4 decades has focused on elucidating both thosemolecular events involved in ATP synthesis by oxidative phosphorylation and those involved inthe biogenesis of the oxidative phosphorylation machinery. While monumental achievements havebeen made, and continue to be made, in the study of these remarkable but extremely complexprocesses essential for the life of most animal cells, it has been only in recent years that a largebody of biological and biomedical scientists have come to recognize that mitochondria participatein other important processes. Two of these are cell death and aging which, not surprisingly, are relatedprocesses both involving, in part, the oxidative phosphorylation machinery. This new awareness hassparked a new and growing area of mitochondrial research, that has become of great interest to awide variety of scientists ranging from those involved in elucidating the role of mitochondria incell death and aging to those interested in either suppressing or facilitating these processes as itrelates to identifying new therapies or drugs for human disease. It is the purpose of this briefintroductory review to provide an overview of those mitochondrial events involved in the life anddeath of animal cells and to indicate how these events might relate to the human aging process.Much more is known, much remains controversial, and even more remains to be learned as indicatedin the excellent set of minireviews that follow.
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  • 87
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    Journal of bioenergetics and biomembranes 31 (1999), S. 321-326 
    ISSN: 1573-6881
    Keywords: Mitochondria ; apoptosis ; caspases ; cytochrome c ; Fas ; bcl-2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract In the past few years, it has become widely appreciated that apoptotic cell death generallyinvolves activation of a family of proteases, the caspases, which undermine the integrity ofthe cell by cleavage of critical intracellular substrates. Caspases, which are synthesized asinactive zymogens, are themselves caspase substrates and this cleavage leads to their activation.Hence, the potential exists for cascades of caspases leading to cell death. However, it has beenrecently recognized that another, perhaps more prominent route to caspase activation, involvesthe mitochondria. Upon receipt of apoptotic stimuli, either externally or internally generated,cells initiate signaling pathways which converge upon the mitochondria to promote release ofcytochrome C to the cytoplasm; cytochrome c, thus released, acts as a potent cofactor incaspase activation. Even cell surface “death receptors” such as Fas, which can trigger directcaspase activation (and potentially a caspase cascade), appear to utilize mitochondria as partof an amplification mechanism; it has been recently demonstrated that activated caspases cancleave key substrates to trigger mitochondrial release of cytochrome c, thereby inducing furthercaspase activation and amplifying the apoptotic signal. Therefore, mitochondria play a centralrole in apoptotic cell death, serving as a repository for cytochrome c.
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  • 88
    ISSN: 1573-6881
    Keywords: Energy expenditure ; reactive oxygen species ; cellular viability ; apoptosis ; necrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Uncoupling proteins, a subgroup of the mitochondrial anion transporter superfamily, have beenidentified in prokaryotes, plants, and mammalian cells. Evolutionary conservation of thesemolecules reflects their importance as regulators of two critical mitochondrial functions, i.e.,ATP synthesis and the production of reactive oxygen species (ROS). Although the amino acidsequences of the three mammalian uncoupling proteins, UCP1, UCP2 and UCP3, are verysimilar, each homolog is the product of a unique gene and important differences have beendemonstrated in their tissue-specific expression and regulation. UCP1 and UCP3 appear to bekey regulators of energy expenditure, and hence, nonshivering thermogenesis, either in brownadipose tissue (UCP1) or skeletal muscle (UCP3). UCP2 is expressed more ubiquitously,although generally at low levels, in many tissues. There is conflicting evidence about itsimportance as a regulator of resting metabolic rate. However, evidence suggests that thishomolog might modulate the mitochondrial generation of ROS in some cell types, includingmacrophages and hepatocytes. While the induction of various uncoupling protein homologsprovides adaptive advantages, both to the organism (e.g., thermogenesis) and to individual cells(e.g., reduced ROS), increased uncoupling protein activity also increases cellular vulnerability tonecrosis by compromising the mitochondrial membrane potential. This narrow “risk—benefit”margin necessitates tight control of uncoupling protein activity in order to preserve cellularviability and much remains to be learned about the regulatory mechanisms involved.
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  • 89
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    Cell biology and toxicology 15 (1999), S. 367-373 
    ISSN: 1573-6822
    Keywords: apoptosis ; drugs ; hepatitis ; mitochondria ; steatosis ; steatohepatitis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mitochondria are involved in fatty acid β-oxidation, the tricarboxylic acid cycle, and oxidative phosphorylation, which provide most of the cell energy. Mitochondria are also the main source of reactive oxygen species in the cell and are involved in cell demise through opening of the mitochondrial permeability transition pore. It was therefore to be expected that mitochondrial dysfunction could be a major mechanism of drug-induced liver disease. Microvesicular steatosis (which may cause liver failure, coma, and death) is the consequence of severe impairment of mitochondrial β-oxidation. Endogenous compounds (such as cytokines or female sex hormones) or xenobiotics (including toxins such as ethanol and drugs such as aspirin, valproic acid, ibuprofen, or zidovudine) can inhibit β-oxidation directly or through a primary effect on the mitochondrial genome or the respiratory chain itself. In some patients, infections and cytokines, or inborn errors of β-oxidation enzymes or the mitochondrial genome, may favor the appearance of drug-induced microvesicular steatosis. Nonalcoholic steatohepatitis may develop under conditions causing prolonged, microvesicular, and/or macrovacuolar steatosis. In this condition, chronic impairment of mitochondrial β-oxidation (causing steatosis) and the respiratory chain (increasing the production of ROS) lead to lipid peroxidation, which, in turn, may cause the diverse lesions of steatohepatitis, namely, necrosis, inflammation, Mallory's bodies, and fibrosis. Finally, mitochondria are involved in several forms of drug-induced cytolytic hepatitis, through inhibition or uncoupling of respiration or through a drug-induced or reactive metabolite-induced mitochondrial permeability transition. The latter effect commits hepatocytes to either apoptosis or necrosis, depending on the number of organelles that have undergone the permeability transition.
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  • 90
    ISSN: 1573-6830
    Keywords: Parkinson's disease ; catecholamines ; oxidative metabolites ; phosphorylation ; DNA damage ; apoptosis ; p53
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. The pathogenesis of the selective degeneration of the dopaminergic neurons in Parkinson's disease is still enigmatic. Recently we have shown that dopamine can induce apoptosis in postmitotic neuronal cells, as well as in other cellular systems, thus suggesting a role for this endogenous neurotransmitter and associated oxidative stress in the neuronal death process. 2. Dopamine has been shown to be capable of inducing DNA damage through its oxidative metabolites. p53 is a transcription factor that has a major role in determining cell fate in response to DNA damage. We therefore examined the possible correlation between dopamine-triggered apoptosis, DNA damage and levels of total phosphorylated p53 protein in cultured mouse cerebellar granule neurons. 3. Marked DNA damage and apoptotic nuclear condensation and fragmentation were detected within several hours of exposure to dopamine. An associated marked threefold increase in p53 phosphorylation was observed within this time window. Using a temperature-sensitive p53 activation system in leukemia LTR6 cells, were found that p53 inactivation dramatically attenuated dopamine toxicity. 4. We therefore conclude that DNA damage and p53 activation may have a role in mediating dopamine-induced apoptosis. Modulation of the p53 system may therefore have a protective role against the toxicity of this endogenous neurotransmitter and associated oxidative stress.
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  • 91
    ISSN: 1573-7217
    Keywords: apoptosis ; Bax ; Bcl‐2 ; breast cancer ; chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Optimizing chemotherapeutic drug delivery strategies relies, in part, on identification of the most clinically effective sequence, dose, and duration of drug exposure. The combination of dose intensive etoposide (VP‐16) followed by cyclophosphamide has clinical efficacy in the treatment of advanced breast cancer. However, molecular mechanisms that underlie the effectiveness of this combination of chemotherapeutic agents have not been investigated. In this study we investigated regulation of BAX and BCL‐2 expression by VP‐16 and cyclophosphamide as a potential mechanism for the induction of breast cancer cell death induced by this regimen. There was a dose and time dependent increase in BAX expression in the breast cancer cell lines MCF‐7, MDA‐MB‐435S, and MDA‐MB‐A231 following in vitro treatment with 50–100 μM VP‐16. Elevation of BAX protein expression in the presence of VP‐16 alone did not correlate with reduced viability or induction of apoptosis in MCF‐7, MDA‐MB‐435S, or MDA‐MB‐A231. VP‐16 did effectively block the breast cancer cell lines evaluated (MCF‐7 and MDA‐MB‐435S) at G2/M phase of the cell cycle, confirming activity of the drug in vitro. MCF‐7 and MDA‐MB‐435S cells that were pre‐treated with VP‐16 and subsequently exposed to 1.0–12.0 μg/m1 4‐hydroperoxycyclophosphamide (4HC), an active metabolite of cyclophosphamide, had markedly reduced viability when compared to matched controls treated with either VP‐16 or 4HC individually. Consistent with this loss of viability, exposure of all three cell lines to the combination of VP‐16 and 4HC resulted in higher BAX protein levels than those observed following treatment with either single agent. This combination of chemotherapeutic agents also resulted in reduced BCL‐2 expression. These observations suggest that combination chemotherapy may derive its efficacy, in part, through coordinated regulation of specific gene products associated with apoptosis. Characterization of molecular events that underlie susceptibility of specific tumor cells to combination chemotherapeutic regimens may lead to additional improvements in treatment strategies for this disease.
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  • 92
    ISSN: 1573-7217
    Keywords: apoptosis ; breast cancer ; doxorubicin ; hsp27 ; topoisomerase II
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previously we demonstrated that heat shock protein 27 (hsp27) overexpression confers resistance to the chemotherapeutic agent doxorubicin in MDA–MB–231 breast cancer cells. Since induction of apoptosis is one underlying mechanism of chemotherapeutic drug action, we investigated the effect of hsp27 overexpression on doxorubicin–induced apoptosis, finding that hsp27 protects MDA–MB–231 cells from apoptosis. We also examined expression of the doxorubicin target, topoisomerase II (topo II), in control and hsp27–overexpressing stable transfectants, as topo II expression is important for both drug sensitivity and the initiation of apoptosis by doxorubicin. The relative levels of both topo IIα and β were higher in the controls than the hsp27–overexpressing clones, suggesting that the apoptotic protective effect of hsp27 overexpression in MDA–MB–231 cells is associated with altered topo II expression.abstract
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  • 93
    ISSN: 1573-7217
    Keywords: angiogenesis inhibitor ; apoptosis ; Bcl‐2 ; breast cancer ; eicosapentaenoic acid ; TNP‐470
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of eicosapentaenoic acid (EPA) and an angiogenesis inhibitor (TNP‐470) on the suppression of breast cancer cell growth were examined in five human breast cancer cell lines (MDA‐MB‐231, T‐47D, MCF‐7, KPL‐1, and MKL‐F). In all five cell lines, EPA and TNP‐470 alone both showed tumor growth inhibition in a time‐ and dose‐dependent manner, and in combination, a synergistic effect was seen at high concentrations. EPA plus TNP‐470 treatment evoked apoptosis as confirmed by the appearance of sub G1 populations, by DNA fragmentation, and by cell morphology. With the combination, the expression of Bax and Bc1‐xS, the apoptosis‐enhancing proteins, was more up‐regulated and that of Bcl‐2 and Bcl‐xL, the apoptosis‐suppressing proteins, was more down‐regulated compared to the use of EPA or TNP‐470 alone, suggesting that their synergistic effect was due to an acceleration of apoptosis.
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  • 94
    ISSN: 1573-7217
    Keywords: apoptosis ; glycogen‐rich breast carcinoma ; prognosis ; proliferation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We determined the proliferation rate and apoptotic activity of glycogen‐rich carcinomas of the breast as opposed to non‐clear cell tumors by means of MIB‐1 immunohistochemistry and in situ detection of oligonucleosomal fragments (TUNEL reaction). The retrospective biopsy series included six invasive clear cell carcinomas of the glycogen‐rich type as well as 15 randomly selected cases of invasive ductal carcinoma without evidence of glycogen storage. Three patients in the clear cell group and seven patients in the control cohort developed lymph‐node metastasis. The MIB‐1 labeling index of glycogen‐rich carcinomas averaged 9.05%, while that of the controls was 30.03%. Apoptotic nuclei were present in a mean of 1.26% of glycogen‐rich carcinoma cells. The control tumors exhibited an average apoptotic frequency of 5.85%. Tumor size, hormone receptor status, and presence or absence of lymph node involvement were found not to correlate with either proliferation or apoptosis. We conclude that glycogen‐rich breast carcinomas are characterized by a peculiar ‘low proliferation‐low apoptosis’ cell kinetic profile. The aggressive clinical behavior of these neoplasms may possibly be accounted for by an ineffective apoptotic elimination of otherwise slowly proliferating tumor cells.
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  • 95
    ISSN: 1573-6903
    Keywords: Calpain ; caspases ; maitotoxin ; necrosis ; apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Maitotoxin is a potent toxin that activates voltage and receptor-mediated Ca2+ channels, resulting in Ca2+ overload and rapid cell death. We report that maitotoxin-induced cell death is associated with activation of calpain but not caspase-3 proteases in septo-hippocampal cell cultures. Calpain and caspase-3 activation were examined by accumulation of protease-specific breakdown products to α-spectrin. Cell death manifested exclusively necrotic-like characteristics including round, shrunken nuclei, even distribution of chromatin, absence of DNA fragmentation and failure of protein synthesis inhibition to reduce cell death. Necrotic cell death was observed in neurons and astroglia. Calpain inhibitor II inhibited calpain-specific processing of α-spectrin and significantly reduced cell death. The pan-caspase inhibitor, Z-D-DCB, nominally attenuated cell death. Results suggest that: (1) calpain, but not caspase-3, is activated as a result of maitotoxin-induced Ca2+ influx; (2) necrotic cell death caused by maitotoxin exposure is partially mediated by calpain activation; (3) maitotoxin is a useful tool to investigate pathological mechanisms of necrosis.
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  • 96
    ISSN: 1573-7217
    Keywords: apoptosis ; Bcl-2 ; breast cancer ; c-Myc ; metastasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The overexpression of Bcl-2, an anti-apoptotic oncogene, identifies human T1 breast cancer patients who have an increased risk of lymph-node metastasis. We examined in these patients (n=142) whether the c-Myc oncogene influences metastatic progression in conjunction or not with Bcl-2 expression and the loss of apoptosis in tumors. The association between Bcl-2 and lymph-node metastasis was only significant when c-Myc was concomitantly expressed (χ2 test, p=0.008). Moreover, very large associations (pOR=6.4) between c-Myc and lymph-node metastasis were observed among Bcl-2 positive tumors and tumors with loss of apoptosis (pOR=8.4). In contrast, the metastatic advantage linked to Bcl-2 was decreased (pOR=2) when c-Myc was not coexpressed. It is concluded that the synergism between Bcl-2 and c-Myc oncogenes may promote metastasis in breast tumors, linked to loss of apoptosis.
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  • 97
    ISSN: 1573-7217
    Keywords: apoptosis ; breast cancer ; doxorubicin ; IGF‐I ; paclitaxel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Insulin‐like growth factor (IGF)‐I protects many cell types from apoptosis. As a result, it is possible that IGF‐I‐responsive cancer cells may be resistant to apoptosis‐inducing chemotherapies. Therefore, we examined the effects of IGF‐I on paclitaxel and doxorubicin‐induced apoptosis in the IGF‐I‐responsive breast cancer cell line MCF‐7. Both drugs caused DNA laddering in a dose‐dependent fashion, and IGF‐I reduced the formation of ladders. We next examined the effects of IGF‐I and estradiol on cell survival following drug treatment in monolayer culture. IGF‐I, but not estradiol, increased survival of MCF‐7 cells in the presence of either drug. Cell cycle progression and counting of trypan‐blue stained cells showed that IGF‐I was inducing proliferation in paclitaxel‐treated but not doxorubicin‐treated cells. However, IGF‐I decreased the fraction of apoptotic cells in doxorubicin‐ but not paclitaxel‐treated cells. Recent work has shown that mitogen‐activated protein kinase (MAPK) and phosphotidylinositol‐3 (PI‐3) kinase are activated by IGF‐I in these cells. PI‐3 kinase activation has been linked to anti‐apoptotic functions while MAPK activation is associated with proliferation. We found that IGF‐I rescue of doxorubicin‐induced apoptosis required PI‐3 kinase but not MAPK function, suggesting that IGF‐I inhibited apoptosis. In contrast, IGF‐I rescue of paclitaxel‐induced apoptosis required both PI‐3 kinase and MAPK, suggesting that IGF‐I‐mediated protection was due to enhancement of proliferation. Therefore, IGF‐I attenuated the response of breast cancer cells to doxorubicin and paclitaxel by at least two mechanisms: induction of proliferation and inhibition of apoptosis. Thus, inhibition of IGF‐I action could be a useful adjuvant to cytotoxic chemotherapy in breast cancer.
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  • 98
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    Angiogenesis 3 (1999), S. 101-116 
    ISSN: 1573-7209
    Keywords: angiogenesis ; apoptosis ; cell death ; endothelial cell ; neovascularization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Angiogenesis, the process of new microvessel development, is encountered in a select number of physiological processes and is central to the pathogenesis of a wide variety of diseases. There is now convincing evidence that regulated patterns of endothelial cell survival and death, a process known as apoptosis, play a central role in the periodic remodeling of the vasculature, and in the timely evolution and regression of angiogenic responses. In this review we discuss the current evidence suggesting a role for inducers and inhibitors of angiogenesis as well as other mediators that modify endothelial cells functions in the survival and death of endothelial cells. We also discuss how dysregulation of apoptosis can lead to aberrant angiogenesis as demonstrated in the pathogenesis of retinopathy of prematurity and cancer.
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  • 99
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    Breast cancer research and treatment 54 (1999), S. 269-278 
    ISSN: 1573-7217
    Keywords: apoptosis ; breast carcinoma ; cell cycle ; curcumin ; cytotoxicity ; gene expression ; RT‐PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Curcumin has anti‐inflamatory, antiproliferative, and antitumor effects. To understand the chemopreventive mechanism of curcumin against human malignancies, the cellular and molecular changes induced by this agent in human mammary epithelial (MCF‐10A) and breast carcinoma (MCF‐ 7/TH) cell lines were investigated. The human multidrug‐ resistant breast cancer cell line was 3.5 fold more sensitive to curcumin than the mammary epithelial cell line. Even though both cell lines accumulated a similar amount of curcumin, a significantly higher percentage of apoptotic cells was induced in breast cancer cells compared to a very low percentage of apoptosis in mammary epithelial cells. Incubation of breast cancer cells with 20 and 40 μM curcumin for 24 h induced G2 block and sub‐ G0/G1 cell population, respectively. Curcumin treatment caused a reduction in the expression of Ki67, PCNA, and p53 mRNAs in breast cancer cells. The human mammary epithelial cell line showed a down‐regulation of p21 mRNA and an up‐regulation of Bax mRNA expression with curcumin treatment. The results suggest that apoptosis is involved in the curcumin‐induced inhibition of tumor cell growth, and genes associated with cell proliferation and apoptosis may be playing a role in the chemopreventive action of curcumin. Abbreviations: EGF: epidermal growth factor; D-MEM: Dulbecco' Modified Eagle Medium; EDTA: ethylene diamine tetra‐acetic acid; PBS: phosphate buffered saline; TdT: terminal deoxynucleotidyl transferase; FBS: fetal bovine serum; RT‐PCR: reverse transcription‐polymerase chain reaction; PCNA: proliferating cell nuclear antigen; TNF: tumor necrosis factor; TPA: 12‐tetradecanoyl‐phorbol‐13‐acetate.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Breast cancer research and treatment 53 (1999), S. 263-269 
    ISSN: 1573-7217
    Keywords: apoptosis ; breast cancer ; neo-adjuvant chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The use of neo-adjuvant chemotherapy (often referred to as pre-operative or primary chemotherapy) represents a major change in the management of breast cancer as a systemic disease. Laboratory studies have shown that many anti-cancer agents with differing modes of action achieve cytotoxic effects by inducing apoptosis. In this study, we investigated the induction of apoptosis by neo-adjuvant chemotherapy in human breast cancer. The aim was to determine whether a correlation existed between post chemotherapy apoptotic index (AI) and clinical response and patients' survival. Our results indicate that apoptosis is induced by neo-adjuvant chemotherapy and that the response is variable. Our data show that post chemotherapy AI correlated with clinical response and increased patient survival, including both relapse (disease) free survival and overall survival. Post-neo-adjuvant chemotherapy AI levels in primary breast cancer may possibly predict an individual patient's overall response.
    Type of Medium: Electronic Resource
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