Activin inhibition of prostate cancer cell growth: selective actions on androgen-responsive LNCaP cells.

Prostate epithelial cell growth is under the control of both steroid and peptide factors. Human prostate cancer cell lines have been used to investigate similar agents in malignancy. Activins are dimeric peptides structurally related to transforming growth factor-beta and produced in the gonads and a wide array of extragonadal tissues. The activins act at the pituitary to regulate the synthesis and secretion of FSH. At other sites, such as bone marrow, liver, and gonads, activin may play an important role in the regulation of cell growth and differentiation. It was the purpose of the current study to determine whether activin had similar actions on prostate cancer cells, specifically the androgen-responsive LNCaP and the androgen-resistant PC-3 cell lines. Using reverse transcription-PCR, messenger RNAs for type I and type II activin receptor subunits as well as the activin-binding protein follistatin were detected in both cell lines. Activin treatment rapidly (<24 h) inhibited LNCaP, but not PC-3, cell g...