LNCaP, a human
prostate cancer cell line, metabolizes
testosterone into a variety of 5 alpha-reduced C19
steroids, such as
dihydrotestosterone (DHT), androstane-3 alpha, 17 beta-diol (3 beta, 17 beta-DIOL), and
androsterone (ADT). Recent reports also suggest that 5 alpha-reduced C19
steroid glucuronides can be detected in the medium. The purpose of this work was to characterize by liquid chromatograph ion spray mass spectroscopy (LCMS) the metabolites formed by LNCaP during incubation with
testosterone and its 5 alpha-reduced C19
steroids. Time course studies using 10 nM labeled
testosterone, 3 alpha-DIOL, 3 beta-DIOL, or ADT showed that a large proportion of polar
steroids were produced by LNCaP. Identification of metabolites produced by LNCaP was carried out by LCMS using 1 microM substrates. Analysis of
testosterone metabolism indicated that
testosterone glucuronide was formed at 77 +/- 2% after 96 h of incubation. Using DHT as substrate,
3 alpha-DIOL-G and DHT-G were the major metabolites, accounting for 46 +/- 4% and 38 +/- 3%, respectively, of the total radioactivity in the medium; ADT-G accounted for 8 +/- 1%. Further analysis by LCMS also indicated that the
glucuronide group in
3 alpha-DIOL-G was at position 17-carbon,
3 alpha-DIOL-G (86 +/- 3%) was the prominent metabolite formed from 3 alpha-DIOL, a minor product was detected at 7 +/- 1% and identified by mass spectrometry to correspond to a trihydroxylated C19
steroid.(ABSTRACT TRUNCATED AT 250 WORDS)