UDP-glucuronosyltransferase 2B15 (UGT2B15) and UGT2B17 enzymes are major determinants of the androgen response in prostate cancer LNCaP cells.
Uridine diphosphate-glucuronosyltransferase 2 (UGT2)B15 and B17 enzymes conjugate dihydrotestosterone (DHT) and its metabolites androstane-3alpha, 17beta-diol (3alpha-DIOL) and androsterone (ADT). The presence of UGT2B15/B17 in the epithelial cells of the human prostate has been clearly demonstrated, and significant 3alpha-DIOL glucuronide and ADT-glucuronide concentrations have been detected in this tissue. The human androgen-dependent cancer cell line, LNCaP, expresses UGT2B15 and -B17 and is also capable of conjugating androgens. To assess the impact of these two genes in the inactivation of androgens in LNCaP cells, their expression was inhibited using RNA interference. The efficient inhibitory effects of a UGT2B15/B17 small interfering RNA (siRNA) probe was established by the 70% reduction of these UGT mRNA levels, which was further confirmed at the protein levels. The glucuronidation of dihydrotestosterone (DHT), 3alpha-DIOL, and ADT by LNCaP cell homogenates was reduced by more than 75% in UGT2B15/B17 siRNA-transfected LNCaP cells when compared with cells transfected with a non-target probe. In UGT2B15/B17-deficient LNCaP cells, we observe a stronger response to DHT than in control cells, as determined by cell proliferation and expression of eight known androgen-sensitive genes. As expected, the amounts of DHT in cell culture media from control cells were significantly lower than that from UGT2B15/B17 siRNA-treated cells, which was caused by a higher conversion to its corresponding glucuronide derivative. Taken together these data support the idea that UGT2B15 and -B17 are critical enzymes for the local inactivation of androgens and that glucuronidation is a major determinant of androgen action in prostate cells.
Chouinard
Sarah
S
Oncology and Molecular Endocrinology Research Center, CHUL Research Center, Québec G1V 4G2, Canada; Faculty of Medicine, Laval University, Québec, G1K 7P4, Canada.
Barbier
Olivier
O
Oncology and Molecular Endocrinology Research Center, CHUL Research Center, Québec G1V 4G2, Canada; Faculty of Pharmacy, Laval University, Québec G1K 7P4, Canada.
Bélanger
Alain
A
Oncology and Molecular Endocrinology Research Center, CHUL Research Center, Québec G1V 4G2, Canada; Faculty of Medicine, Laval University, Québec, G1K 7P4, Canada. Electronic address: alain.belanger@ap.ulaval.ca.
D000728:Androgens / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D014453:Glucuronosyltransferase / Q000737:chemistry* / Q000502:physiology*; D006801:Humans; D008297:Male; D015778:Minor Histocompatibility Antigens; D008954:Models, Biological; D011471:Prostatic Neoplasms / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
D000728:Androgens; D015778:Minor Histocompatibility Antigens; D034741:RNA, Small Interfering; D014453:Glucuronosyltransferase; C472000:UDP-glucuronosyltransferase 2B15, human; C500513:UGT2B17 protein, human