EXPRESSION OF TRANSFORMING GROWTH-FACTOR-BETA-1 IN RAT VENTRAL PROSTATE AND DUNNING R3327 PAP PROSTATE TUMOR AFTER CASTRATION AND ESTROGEN-TREATMENT

BACKGROUND. In normal prostate, TGF-beta 1 is associated to castration induced apoptosis. Combined castration and estrogen treatment, but no t castration alone, induces apoptosis in the Dunning R3327 PAP adenoca rcinoma. METHODS. TGF-beta 1 expression in rat ventral prostate (VP) a nd Dunning R3327 PAP tumor was studied after castration and estrogen t reatment, using competitive RT-PCR, in situ hybridization and immunohi stochemistry. RESULTS. TGF-beta 1 mRNA level was 6 times higher in the tumor than in the VP. Combined castration and estrogen treatment incr eased TGF-beta 1 mRNA levels in the tumor from day 3, while castration did not. The TGF-beta 1 expression was located in the epithelial cell s. CONCLUSIONS. The Dunning R3327 PAP tumor contains high levels of TG F-beta 1, which are further increased by combined castration and estro gen treatment. However, since this increase is not apparent until day 3, TGF-beta 1 probably does not contribute to the known induction of a poptosis in the tumor at day 1 after combined castration and estrogen treatment. (C) 1996 Wiley-Liss, Inc.