EXPRESSION OF TRANSFORMING GROWTH-FACTOR-BETA-1 (TGF-BETA(1)), TGF-BETA(2), AND TGF-BETA(3) BY CULTURED HUMAN PROSTATE CELLS

Transforming growth factor betas (TGF beta s) are members of a superfa mily of polypeptides that control cell cycle progression and a variety of other cellular activities. TGF beta family members, -beta 1, -beta 2, and -beta 3, have been identified in prostate. The levels of expre ssion of these TGF beta isotypes have been reported to vary with the p athologic state of the prostate. While the significance of these obser vations remains to be elucidated there is little doubt that TGF beta s play an important role in controlling growth of the prostate. The pro static cells expressing TGF beta s have not been identified. This info rmation would provide insight into the physiologic role of TGF beta s and suggest ways that growth control may be altered in prostate diseas e. We used stromal (PS) and epithelial (PE) cells, cultured from norma l human prostate and benign prostatic hyperplasia (BPH), to study the effect of TGF beta s on cell proliferation and TGF beta transcript ari d protein expression. The proliferation of PS and PE was inhibited by pM quantities of TGF beta 1, -beta 2, and -beta 3. Both cell types exp ressed transcripts for all three TGF beta isotypes, but PS primarily s ecreted TGF beta 1, whereas PE secreted more TGF beta 2 than TGF beta 1. These observations suggest that TGF beta s are antiproliferative ag ents in vivo, and that the stroma is the source of TGF beta 1 while th e epithelium is the major source of TGF beta 2 in prostate. There were no significant differences in the growth response to TGF beta s, the TGF beta-isotype expressed, or the amount of TGF beta secreted by cell s cultured from normal prostate or BPH. (C) 1996 Wiley-Liss Inc.