Inhibitory effect of transforming growth factor-beta on epidermal growth factor-induced proliferation of cultured rat aortic smooth muscle cells.

This study was conducted to investigate the effect of transforming growth factor-beta (TGF-beta) on the proliferation of cultured rat aortic smooth muscle cells (SMCs). DNA synthesis, measured by the incorporation of [3H] thymidine, and the cell number of monolayered SMCs were measured after incubation with TGF-beta (1-100 ng/ml) in the presence or absence of epidermal growth factor (EGF; 100 ng/ml). TGF-beta alone did not affect DNA synthesis of SMCs. EGF significantly increased both DNA synthesis and cell number, while TGF-beta inhibited the increase in both in a dose-dependent manner without accompanying the significant cellular damage. These results indicate that TGF-beta exerts an inhibitory effect on the proliferation of cultured SMCs provoked by EGF.