Expression of transforming growth factor-beta 1 in rat ventral prostate and Dunning R3327 PAP prostate tumor after castration and estrogen treatment

Abstract

Background: In normal prostate, TGF-beta 1 is associated to castration induced apoptosis. Combined castration and estrogen treatment, but not castration alone, induces apoptosis in the Dunning R3327 PAP adenocarcinoma.

Methods: TGF-beta 1 expression in rat ventral prostate (VP) and Dunning R3327 PAP tumor was studied after castration and estrogen treatment, using competitive RT-PCR, in situ hybridization and immunohistochemistry.

Results: TGF-beta 1 mRNA level was 6 times higher in the tumor than in the VP. Combined castration and estrogen treatment increased 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 cells.

Conclusions: The Dunning R3327 PAP tumor contains high levels of TGF-beta 1, which are further increased by combined castration and estrogen treatment. However, since this increase is not apparent until day 3, TGF-beta 1 probably does not contribute to the known induction of apoptosis in the tumor at day 1 after combined castration and estrogen treatment.