Bombesin stimulation of c- fos and c- myc gene expression in cultures of Swiss 3T3 cells

Bombesin has been shown to be a potent mitogen for Swiss 3T3 cells. At nanomolar concentrations it stimulates DNA synthesis in quiescent cultures of 3T3 cells and also induces the expression of c- fos and c- myc mRNA. c- fos mRNA transcripts dramatically increase 15 min after the addition of bombesin, are still abundant after 30–60 min and then decrease, c- myc mRNA induction is detectable later, 1 h after bombesin treatment. Conversely, no changes in c-Ki- ras expression are observed after stimulation with bombesin. These results demonstrate that the increased expression of c- fos and c- myc mRNAs appears to be a common response to diverse agents that induce DNA synthesis and cell proliferation.