TRANSFORMING GROWTH FACTOR-BETA-3 IS EXPRESSED IN NONDIVIDING BASAL EPITHELIAL-CELLS IN NORMAL HUMAN PROSTATE AND BENIGN PROSTATIC HYPERPLASIA, AND IS NO LONGER DETECTABLE IN PROSTATE CARCINOMA

BACKGROUND. We investigated the role of the transforming growth factor beta (TGF-beta) family in the neoplastic progression of the human pro state. METHODS. Expression of TGF-beta mRNA was measured by Northern b lot analysis of tissue extracts, and TGF-beta protein by immunohistoch emical analysis of tissue sections. Proliferating cells were detected by their expression of Ki-67 antigen. RESULTS. The level of TGF-beta 1 mRNA was equal among normal prostate, benign prostatic hyperplasia (B PH), and prostate carcinoma. TGF-beta 2 mRNA was not detectable, and T GF-beta 3 mRNA was expressed 20-fold lesion in carcinoma compared to B PH and normal prostate. TGF-beta 1 protein was expressed in the stroma l cells in all three tissues and TGF-beta 3 protein in the basal layer of epithelial cells, but not in carcinoma. Proliferating epithelial c ells fail to express TGF-beta 3. CONCLUSIONS. TGF-beta 1 and TGF-beta 3 are independently regulated, and carcinoma of the prostate is charac terized by the loss of basal epithelial cells expressing TGF-beta 3. ( C) 1997 Wiley-Liss, Inc.