Transforming growth factor beta in the human prostate: Its role in stromal-epithelial interactions in non-cancerous cell culture

BACKGROUND. Stromal-epithelial interactions play a critical role in prostat e development, but the precise mechanisms are still unknown. Transforming g rowth factor-beta (TGF beta) could be a potential mediator of these interac tions, but there is as yet no clear demonstration of its role. METHODS. Separate cultures and co-cultures of fibroblasts and epithelial hu man prostate cells were performed. We measured TGF beta1 and TGF beta2 secr etion by specific ELISA assay, cell growth by DNA assay, and TGF beta type II receptor expression by RT-PCR. RESULTS. Go-culture resulted in a 20% inhibition of epithelial cell growth, similar to that obtained after TGF beta treatment (2 ng/ml for 48 hr), but without affecting fibroblast proliferation. This was accompanied by a five - to six-fold increase in epithelial TGF beta2 secretion. CONCLUSIONS. These results demonstrate for the first time that TGF beta2 se cretion by prostate epithelial cells is under the direct control of a diffu sible factor secreted by fibroblasts. They emphasize the role of TGF beta i n stromal-epithelial interactions. Prostate 46:311-318, 2001. (C) 2001 Wile y-Liss,Inc.