11β-Hydroxyandrostenedione, the product of androstenedione metabolism in the adrenal, is metabolized in LNCaP cells by 5α-reductase yielding 11β-hydroxy-5α-androstanedione

11 beta-Hydroxyandrostenedione (11OHA4), which is unique to the adrenal, was first isolated from human adrenal tissue in the fifties. It was later shown in the sixties that 11 beta-hydroxytestosterone (11OHT) was also produced by the human adrenal. Attention has shifted back to these adrenal androgens once more, as improved analytical techniques have enabled more accurate detection of steroid hormones. In this paper, we investigated the origin of these metabolites as well as their subsequent metabolism and examined a possible physiological role for 11OHA4 in prostate cancer cells. In H295R cells treated with forskolin and trilostane, etomidate, a reported cytochrome P450 11 beta-hydroxylase (CYP11B1) inhibitor, blocked the production of corticosterone, cortisol, 11OHA4 and 11OHT. The metabolism of androstenedione and testosterone by CYP11B1 and aldosterone synthase (CYP11B2) was assayed. Androstenedione was converted by CYP11B1, while the conversion by CYP11B2 was negligible. Both enzymes readily converted testosterone. The metabolism of these 11 beta-hydroxylated metabolites by 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) types land 2 was subsequently investigated. 11 beta HSD2 catalyzed the conversion of both 11OHA4 and 11OHT to their respective keto-steroids, while 11 beta HSD1 catalyzed the conversion of 11-ketoandrostenedione and 11-ketotestosterone to their respective hydroxy-steroids in Chinese hamster ovary cells. Investigating a functional role, steroid 5 alpha-reductase types 1 and 2 converted 11OHA4 to 11 beta-hydroxy-5 alpha-androstanedione (11OH-5 alpha-dione), identified by accurate mass detection. UPLC-MS/MS analyses of 11OHA4 metabolism in LNCaP androgen-dependent prostate cancer cells, identified the 5 alpha-reduced metabolite as well as 11-ketoandrostenedione and 11-ketotestosterone, with the latter indicating conversion by 17 beta-hydroxysteroid dehydrogenase. Downstream metabolism by 11 beta HSD2 and by 5 alpha-reductase may therefore indicate a physiological role for 11OHA4 and/or 11OH-5 alpha-dione in normal and prostate cancer cells. (C) 2013 Elsevier Ltd. All rights reserved.