Role of the c-fos gene expression on the mitogenic response in EL2 rat fibroblasts

Abstract

Stimulation of the growth of quiescent fibroblasts by polypeptide growth factors is accompanied by the rapid induction of the c-fos proto-oncogene. To investigate whether there exists a relationship between mitogenic activity and c-fos expression, we analysed cellular responses (DNA synthesis and cell growth) and c-fos gene induction (mRNA and proteins) in a rat embryo fibroblast line (EL2) stimulated with epidermal growth factor (EGF), fibroblast growth factor (FGF), 12-O-tetradodecanoyl phorbol-13-acetate (TPA) and transforming growth factor beta (TGF beta). Our results suggest that the susceptibility of EL2 cells to a growth factor could be predicted as a function of the c-fos expression caused by the same growth factor. These also indicate that the c-fos gene expression may have contributed to moving our cells out of the quiescent state, but it is not the only essential event required to effect EL2 cell growth.