ISSN:
0730-2312
Keywords:
oncogenes
;
neoplastic transformation
;
transforming growth factor-α
;
transforming growth factor-β
;
basic fibroblast growth factor
;
platelet-derived growth factor
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
The expression of growth factor-specific mRNA transcripts and the presence of biologically active growth factors in the conditioned medium and in the cell extracts from mouse NIH-3T3 cells transformed by different oncogences (Ki-ras, mos, src, fms, fes, met, and trk), by DNA tumor virus (SV40), or by a chemical carcinogen (N-nitrosomethylurea) were studied. In contrast to NIH-3T3 cells or simain virus 40 (SV40)-transformed 3T3 cells, all the other transformed NIH-3T3 cell lines express a 4.5 kb transforming growth factor-α (TGFα)-specific mRNA transcript and secreted immunoreactive and biologically active TGFα ranging from 100 to 225 ng/108 cell/48 h. In addition, in the transformed cell lines that were secreting elevated levels of biologically active TGFα, there was a 75-95% reduction in the total number of epidermal growth factor receptors on these cells. A 2.6 kb TGFβ mRNA transcript and TGFβ protein in the conditioned medium (30-140ng/108 cells/48h) was also detected in those lines expressing TGFα. Basic fibroblast growth factor-like activity (11-50 ng/108 cells) was detected in the cell lysates from NIH-3T3 cells transformed with N-nitrosomethylurea or with trk, where expression of specific 6.9 and 3.9 kb mRNA transcripts for basic fibroblast growth factor could also be found. B chain (c-sis) expression of platelet-derived growth factor was present only in trk-transformed NIH-3T3 cells in which specific c-sis 6.5 and 4.6 kb transcripts were identified. In contrast, platelet-derived growth factor A chain expression of 2.9 and 2.3 kb transcripts was found in ras-, met-, mos-, and fms-transformed NIH-3T3 cells. These results suggest that the expression of different sets of growth factors is controlled in part by structurally distinct groups of transforming genes.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcb.240420105
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