506 INTRACRINE DYNAMICS OF CYP17A1 ACTIVITIES IN HUMAN CASTRATION RESISTANT PROSTATE CANCER

Abstract

You have accessJournal of UrologyProstate Cancer: Basic Research (III)1 Apr 2013506 INTRACRINE DYNAMICS OF CYP17A1 ACTIVITIES IN HUMAN CASTRATION RESISTANT PROSTATE CANCER Takeo Kosaka, Akira Miyajima, Takahiro Maeda, Hirohiko Nagata, Yota Yasumizu, Eiji Kikuchi, and Mototsugu Oya Takeo KosakaTakeo Kosaka Tokyo, Japan More articles by this author , Akira MiyajimaAkira Miyajima Tokyo, Japan More articles by this author , Takahiro MaedaTakahiro Maeda Tokyo, Japan More articles by this author , Hirohiko NagataHirohiko Nagata Tokyo, Japan More articles by this author , Yota YasumizuYota Yasumizu Tokyo, Japan More articles by this author , Eiji KikuchiEiji Kikuchi Tokyo, Japan More articles by this author , and Mototsugu OyaMototsugu Oya Tokyo, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1900AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Although accumulating evidences indicates high expression of CYP17A1 allows castration resistant prostate cancer (CRPC) to maintain high intratumoral androgen levels, the potential CYP17A1 activity has not been characterized yet. The aim of this study was to examine the CYP17A1 expression and the potential CYP17A1 activity including 17α-hydroxylase and 17, 20-lyase activities in human CRPC. METHODS We used two human CRPC cell lines: C4-2 and C4-2AT6 which was established from C4-2 under androgen ablation conditions for six months. We quantified and compared transcripts and the protein expression of CYP17A1. To ascertain the potential CYP17A1 activity, we cultured with the steroid precursors: 13C-[2,3,4]-progesterone (13C-Prog), and analyzed the sequential biosynthesis 13C-[2,3,4]-17-hydroxyprogesterone (13C-17OHP) and 13C-[2,3,4]-androstenedione(13C-Adione). For the measurement of 13C-Adione and 13C-17OHP in cultured medium, an API-4000 triple stage quadrupole mass spectrometer connected to Agilent 1100, HTC-PAL, and an ESI ion source: liquid chromatography/mass spectrometry (LC/MS/MS) was employed. RESULTS Compared with C4-2 cells, quantitative PCR (qPCR) for C4-2AT6 cells showed significant increases of the expression of CYP17A1(p<0.001). Western blot analysis revealed significant increases of the expression of CYP17A1 at the protein level. LC/MS/MS analysis enabled us to detect the 13C-17-OHP and 13C-A-dione in these cell lines. The concentration ratio of 13C-Adione/13C-17-OHP (Adione-17-OHP ratio), which is thought to reflect the differences between 17-hydroxylase and 17, 20-lyase activities, was then determined. In C4-2 cells, the concentration of 13C-17-OHP and 13C-A-dione were 31.3±3.8 and 4.1±1.8 pg/mL; thus the Adione-17-OHP ratio was 0.135±0.07. On the other hand, in C4-2AT6 cells, the concentrations of 13C-17-OHP and 13C-Adione were 17.6±2.6 pg/mL and 6.9±0.5 pg/mL, and the Adione-17-OHP ratio was 0.402±0.09. Adione-17-OHP ratio was significantly higher in C4-2 than that of C4-2AT6 (p<0.001). These results indicated that both C4-2 and C4-2AT6 cells expressed direct CYP17A1 activities and that 17, 20-lyase activity was significantly higher in C4-2AT6 cells than in C4-2 cells. CONCLUSIONS These results demonstrated the direct evidence of intracrine dynamics of CYP17A1 activities mediated by 17α-hydroxylase activity and 17, 20-lyase activity in human CRPC. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e207-e208 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Takeo Kosaka Tokyo, Japan More articles by this author Akira Miyajima Tokyo, Japan More articles by this author Takahiro Maeda Tokyo, Japan More articles by this author Hirohiko Nagata Tokyo, Japan More articles by this author Yota Yasumizu Tokyo, Japan More articles by this author Eiji Kikuchi Tokyo, Japan More articles by this author Mototsugu Oya Tokyo, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...