Differential growth factor expression in transformed mouse NIH-3T3 cells

✍ Scribed by Fortunato Ciardiello; Eva M. Valverius; G. Luca Colucci-D'Amato; Nancy Kim; Robert H. Bassin; David S.Salomon

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 954 KB
• Volume: 42
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240420105

✦ Synopsis

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 oncogenes (Ki-rus, mos, src, fms, fes, met, and trk), by a DNA tumor virus (SVN), or by a chemical carcinogen (N-nitrosomethylurea) were studied. In contrast to NIH-3T3 cells or simian virus 40 (SVN)-transformed 3T3 cells, all the other transformed NIH-3T3 cell lines expressed a 4.5 kb transforming growth factor-a (TGFa)-specific mRNA transcript and secreted immunoreactive and biologically active TGFa ranging from 100 to 225 ng/108 cells/48 h. In addition, in the transformed cell lines that were secreting elevated levels of biologically active TGFa, there was a 75-95% reduction in the total number of epidermal growth factor receptors on these cells. A 2.6 kb TGFD mRNA transcript and TGFD protein in the conditioned medium (30-140 ng/108 cells/48 h) was also detected in those lines expressing TGFa. Basic fibroblast growth factor-like activity (1 1-50 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 trktransformed 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 rus-, 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.