ISSN:
0730-2312
Keywords:
kinase FA/GSK-3α
;
overexpression
;
thyroid
;
tumor cell dedifferentiation
;
carcinogenesis
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Computer analysis of protein phosphorylation sites sequence revealed that transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of the proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of protein kinase FA/glycogen synthase kinase-3α (kinase FA/GSK-3α) (a member of the PDPK family) has been optimized for human thyroid tissue and used to demonstrate for the first time significantly increased (P 〈 0.001) activity in thyroid carcinoma (24.2 ± 2.8 units/mg of protein) (n = 7), thyroid adenoma (14.5 ± 2.2 units/mg of protein) (n = 6), and thyroid hyperplasia (8.0 ± 2.4 units/mg of protein) (n = 5) when compared to five normal controls (4.1 ± 1.8 units/mg of protein). Immunoblotting analysis further revealed that increased activity of kinase FA/GSK-3α in thyroid tumor cells is due to overexpression of protein level and cellular activity of kinase FA/GSK-3α is involved in human thyroid tumor cell dedifferentiation, supporting an association of PDPK with neoplastic transformation and tumorigenesis. Since kinase FA/GSK-3α may function as a possible regulator of transcription factors/protooncogenes, kinase FA/GSK-3α may therefore play an important role in thyroid cell carcinogenesis, especially in its differentiation.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcb.240580410
Permalink
