Antiandrogenic Effects of a Polyphenol in Carex kobomugi through Inhibition of Androgen Synthetic Pathway and Downregulation of Androgen Receptor in Prostate Cancer Cell Lines

Int J Mol Sci. 2022 Nov 18;23(22):14356. doi: 10.3390/ijms232214356.

Abstract

Prostate cancer (PC) represents the most common cancer disease in men. Since high levels of androgens increase the risk of PC, androgen deprivation therapy is the primary treatment; however this leads to castration-resistant PC (CRPC) with a poor prognosis. The progression to CRPC involves ectopic androgen production in the adrenal glands and abnormal activation of androgen signaling due to mutations and/or amplification of the androgen receptor (AR) as well as activation of androgen-independent proliferative pathways. Recent studies have shown that adrenal-derived 11-oxygenated androgens (11-ketotestosterone and 11-ketodihydrotestosterone) with potencies equivalent to those of traditional androgens (testosterone and dihydrotestosterone) are biomarkers of CRPC. Additionally, dehydrogenase/reductase SDR family member 11 (DHRS11) has been reported to be a 17β-hydroxysteroid dehydrogenase that catalyzes the production of the 11-oxygenated and traditional androgens. This study was conducted to evaluate the pathophysiological roles of DHRS11 in PC using three LNCaP, C4-2 and 22Rv1 cell lines. DHRS11 silencing and inhibition resulted in suppression of the androgen-induced expression of AR downstream genes and decreases in the expression of nuclear AR and the proliferation marker Ki67, suggesting that DHRS11 is involved in androgen-dependent PC cell proliferation. We found that 5,7-dihydroxy-8-methyl-2-[2-(4-hydroxyphenyl)ethenyl]-4H-1-benzopyran-4-one (Kobochromone A, KC-A), an ingredient in the flowers of Carex kobomugi, is a novel potent DHRS11 inhibitor (IC50 = 0.35 μM). Additionally, KC-A itself decreased the AR expression in PC cells. Therefore, KC-A suppresses the androgen signaling in PC cells through both DHRS11 inhibition and AR downregulation. Furthermore, KC-A enhanced the anticancer activity of abiraterone, a CRPC drug, suggesting that it may be a potential candidate for the development of drugs for the prevention and treatment of CRPC.

Keywords: Carex kobomugi; DHRS11; androgen receptor; polyphenol; prostate cancer.

MeSH terms

  • 17-Hydroxysteroid Dehydrogenases / genetics
  • Androgen Antagonists / therapeutic use
  • Androgens / metabolism
  • Carex Plant* / metabolism
  • Cell Line, Tumor
  • Down-Regulation
  • Humans
  • Male
  • Polyphenols / therapeutic use
  • Prostatic Neoplasms, Castration-Resistant* / drug therapy
  • Prostatic Neoplasms, Castration-Resistant* / genetics
  • Prostatic Neoplasms, Castration-Resistant* / metabolism
  • Receptors, Androgen / genetics
  • Receptors, Androgen / metabolism

Substances

  • Receptors, Androgen
  • Androgens
  • Polyphenols
  • Androgen Antagonists
  • DHRS11 protein, human
  • 17-Hydroxysteroid Dehydrogenases