Transforming growth factor β1, insulin and prostaglandin E₁ enhance prostaglandin F_2α mitogenic action in Swiss 3T3 cells via separate events

Abstract

Transforming growth factorb (TGFBl) had no mitogenic effect in Swiss 3T3 cells, but could increase prostaglandin F, (PGFZa)-induced DNA synthesis. Insulin, but not prostaglandin E, (PGEl), further enhanced PGF2cr action at low TGFpl concentrations. TGFBl also acted concertedly with the protein kinase C (PKC) activator I-oleoyl-2-acetylglycerol to induce mitogenesis. Thus, it appears that TGFBl and insulin act via separate signals, while TGFBl and PGEl might share a common pathway not involving TGF/?l-mediated prostaglandin synthesis. These results suggest that TGFBl might elicit various signalling mechanisms to enhance PGFZa-triggered events.