Transforming growth factor beta (TGF-beta) is a potent inhibitor of the proliferation of many cell types. We investigated the effects of TGF-beta1 on cyclin D1, cyclin A, p21, p27, and p53 mRNA expressions in primary cultured rat hepatocytes by the reverse-transcription polymerase chain reaction (RT-PCR) method. TGF-beta1 decreased the level of cyclin A mRNA in a dose-dependent manner, while it had little effect on the level of cyclin D1 mRNA. p21 mRNA expression was greatly induced by TGF-beta1 in a p53-independent mechanism, while p27 mRNA expression was not affected by TGF-beta1. These results suggest that TGF-beta1 may inhibit liver cell proliferation by regulating p21 and cyclin A mRNAs.
Copyright 1997 Academic Press.