Urologic Oncology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York.
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 physiological 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 that 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 LHRH agonists or antagonists, AR antagonists, inhibitors of 5α-reductase enzymes, finasteride or dutasteride, and steroid metabolism enzyme inhibitors, ketoconazole or the recently available abiraterone acetate.
Mohler JL, Titus MA, Wilson EM. Are you the author?
Reference: Clin Cancer Res. 2011 Jun 24. Epub ahead of print.