Inhibition of the Androgen Receptor Activity by Coprinus comatus Substances

Abstract

Prostatic adenocarcinoma is the second leading cause of death from cancer in Western men. The common prostate cancer treatments are effective in the early stages; however, advanced prostate cancer is resilient to most of these treatments. Altered androgen receptor (AR) activity caused by point mutations or signaling mechanisms that regulate AR function has been proposed as a key mechanism in the transition to the androgen-independent stage. Our previous results demonstrated that hexane extract prepared from Coprinus comatus (C. comatus) strain 734 was able to interfere with AR activity. The current study was made to further evaluate the antiandrogenic activity of the C. comatus mushroom strain 734. Activity-guided chromatography was conducted and 2 active fractions, F-32-and F-33, were found to contain substances that were able to inhibit AR-mediated reporter activity and reduce the levels of AR and prostate-specific antigen (PSA) transcripts in LNCaP cells. Fraction F-32 also inhibited the proliferation and clonigenicity of LNCaP cells. Furthermore, F-32 was able to inhibit the binding of AR to the PSA enhancer region and to inhibit Akt-mediated AR phosphorylation at Ser 213. This study illustrated the potential of substances from the C. comatus mushroom to serve as natural antiandrogenic modulators for the treatment of prostatic disorders.