Epidermal growth factor increases c-myc mRNA without eliciting phosphoinositide turnover, protein kinase C activation, or calcium ion mobilization in swiss 3T3 fibroblasts

Incubation of quiescent cultures of Swiss 3T3 cells with epidermal growth factor (EGF) caused an increase in c-myc mRNA. Under these conditions, EGF did not induce phosphoinositide turnover, formation of diacylglycerol, formation of inositol tris-, bis-, and monophosphates, protein kinase C activation, or Ca²⁺ mobilization. Although it has been reported that both protein kinase C and Ca²⁺ may be responsible for the platelet-derived growth factor- and fibroblast growth factor-induced increases in c-myc mRNA in Swiss 3T3 cells (Kaibuchi, K., Tsuda, T., Kikuchi, A., Tanimoto, T., Yamashita, T., & Takai, Y. (1986) J. Biol. Chem. 261, 1187-1192), these results indicate that neither protein kinase C nor Ca²⁺ is involved in the EGF-induced increase in c-myc mRNA, and that an unidentified system may be involved in this reaction.