Signal transduction cascade shared by epidermal growth factor and platelet-derived growth factor is a major pathway for oncogenic transformation in NRK cells.

We have isolated two recessive, mutually complementary NRK cell mutants that are refractory to transformation by epidermal growth factor (EGF) and transforming growth factor-beta. Both mutants are defective in a signal transduction cascade shared by EGF and platelet-derived growth factor (PDGF). Analysis of the mutants suggests that transformation of NRK cells by the v-fms, v-erbB, activated erbB-2, v-ras, v-fos, v-mos, v-fes, v-src, SV40 large T, polyomavirus middle T, and human papillomavirus type 16 E6,E7 oncogenes is mediated by the EGF/PDGF signal cascade. The data also suggest that the EGF/PDGF cascade branches into mitogenic and oncogenic signals, the latter of which is required for soft agar growth and focus formation.