Trilostane, an inhibitor of 3β-hydroxysteroid dehydrogenase, has an agonistic activity on androgen receptor in human prostate cancer cells.

The intracellular androgen metabolism and cell activity in prostate cancer cells with mutated (LNCaP-FGC) or wild-type (VCaP) androgen receptors in the presence of trilostane, an inhibitor of 3β-hydroxysteroid dehydrogenase, were examined. Trilostane suppressed the intracellular production of androstenedione, testosterone, and dihydrotestosterone from dehydroepiandrosterone in LNCaP-FGC cells. In both LNCaP-FGC and VCaP cell types, the prostate-specific antigen (PSA) levels in media were increased by trilostane alone in a concentration-dependent manner. Both cells pretreated with trilostane showed a dose-dependent decrease in PSA production with bicalutamide (P<0.001). Trilostane should be used with particular concern when treating prostate cancer.