Differential responsiveness of myc- and ras-transfected cells to growth factors: selective stimulation of myc-transfected cells by epidermal growth factor.
AUTOR(ES)
Stern, D F
RESUMO
To identify functional relationships between oncogenes and growth factors, we compared the effects of transfected myc and ras oncogenes on the responsiveness of Fischer rat 3T3 cells to three growth factors: epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and transforming growth factor-beta (TGF-beta). Control cells did not grow in soft agar under any conditions. ras-Transfected cells grew in soft agar under all conditions tested and were insensitive to the stimulatory effects of exogenous growth factors. These cells secreted elevated levels of both EGF-like factors and TGF-beta, suggesting that the lack of responsiveness of these cells to exogenous growth factors arose from autocrine stimulation. myc-Transfected cells displayed conditional anchorage-independent growth: they formed numerous colonies in soft agar in the presence of EGF but relatively few colonies in the presence of PDGF or TGF-beta. Secretion of EGF-like factors and TGF-beta by these cells was not elevated above that of control cells. These results suggest a model for the mechanism of cooperation between myc and ras oncogenes in which ras-like genes induce growth factor production, while myc-like genes increase the responsiveness of cells to these factors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=367587Documentos Relacionados
- Alteration of glycolipids in ras-transfected NIH 3T3 cells.
- Tumorigenic and metastatic properties of "normal" and ras-transfected NIH/3T3 cells.
- Stimulation of glycolysis and amino acid uptake in NRK-49F cells by transforming growth factor beta and epidermal growth factor.
- Stimulation of wound healing by epidermal growth factor. A dose-dependent effect.
- Growth regulation of skin cells by epidermal cell-derived factors: implications for wound healing.
