title: Potential prostate cancer drug target: bioactivation of androstanediol by conversion to dihydrotestosterone.
abstract: High-affinity binding of dihydrotestosterone (DHT) to the androgen receptor (AR) initiates androgen-dependent gene activation, required for normal male sex development in utero, and contributes to prostate cancer development and progression in men. Under normal physiologic conditions, DHT is synthesized predominantly by 5α-reduction of testosterone, the major circulating androgen produced by the testis. During androgen deprivation therapy, intratumoral androgen production is sufficient for AR activation and prostate cancer growth, even though circulating testicular androgen levels are low. Recent studies indicate that the metabolism of 5α-androstane-3α, 17β-diol by 17β-hydroxysteroid dehydrogenase 6 in benign prostate and prostate cancer cells is a major biosynthetic pathway for intratumoral synthesis of DHT, which binds AR and initiates transactivation to promote prostate cancer growth during androgen deprivation therapy. Drugs that target the so-called backdoor pathway of DHT synthesis provide an opportunity to enhance clinical response to luteinizing-hormone-releasing hormone (LHRH) agonists or antagonists, AR antagonists, and inhibitors of 5α-reductase enzymes (finasteride or dutasteride), and other steroid metabolism enzyme inhibitors (ketoconazole or the recently available abiraterone acetate).
authors.affiliation: Department of Urology, Roswell Park Cancer Institute, Department of Urology, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Mohler
authors.forename: Mark A
authors.initials: MA
authors.lastname: Titus
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Wilson
mesh_terms: D015114:Androstenediol / Q000378:metabolism*; D042944:Cholestenone 5 alpha-Reductase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013196:Dihydrotestosterone / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008297:Male; D058990:Molecular Targeted Therapy; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D013254:Steroid 17-alpha-Hydroxylase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D013196:Dihydrotestosterone; D015114:Androstenediol; C501892:CYP17A1 protein, human; D013254:Steroid 17-alpha-Hydroxylase; D042944:Cholestenone 5 alpha-Reductase