Characterization of 5alpha-reductase gene expression in stroma and epithelium of human prostate

J Steroid Biochem Mol Biol. 1996 Dec;59(5-6):397-404. doi: 10.1016/s0960-0760(96)00125-2.

Abstract

The expression of 5alpha-reductase type 1 and type 2 isoenzymes in hyperplastic human prostate tissue and several human prostate cell lines was investigated by Northern blot analyses, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme activity. Separation of stroma and epithelium was confirmed histologically and only preparations with no apparent contamination were employed in the subsequent studies. Poly(A)+ RNA was isolated from stromal and epithelial fractions and analysed by Northern blot and RT-PCR. Inhibition of epithelial and stromal 5alpha-reductase activities by 17beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5alpha-androstan- 3-one (4MA) was assessed using a range of concentrations between 10(-13) and 10(-5) M. Results from Northern blot analyses and RT-PCR showed that the prostate stroma expressed 5alpha-reductase type 1 and type 2 isoenzymes, whereas the prostate epithelium only expressed 5alpha-reductase type 1. This was consistent with biphasic inhibition of 5alpha-reductase activity by 4MA in stroma and monophasic inhibition in epithelium. Cultured epithelial cells derived from human prostate only expressed 5alpha-reductase type 1 and had Vmax and Km values that approximated the lower end of the range reported for surgically removed prostate epithelium. The foregoing data explains the disparate activities of 5alpha-reductase, previously reported, in stroma and epithelium. The differential localization of these isoenzymes in the prostate suggests that future therapy of androgen-sensitive disease may be more successful through the use of selective inhibitors of the different 5alpha-reductase isoenzymes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Androgen Antagonists / pharmacology
  • Azasteroids / pharmacology
  • Blotting, Northern
  • Cholestenone 5 alpha-Reductase
  • Dihydrotestosterone / analogs & derivatives
  • Dihydrotestosterone / pharmacology
  • Epithelium / drug effects
  • Epithelium / metabolism
  • Epithelium / pathology
  • Gene Expression Regulation, Enzymologic
  • Humans
  • Hyperplasia / enzymology
  • Hyperplasia / genetics
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Kinetics
  • Male
  • Middle Aged
  • Oxidoreductases / antagonists & inhibitors
  • Oxidoreductases / genetics*
  • Oxidoreductases / metabolism*
  • Polymerase Chain Reaction / methods
  • Prostate / cytology*
  • Prostate / metabolism*
  • Prostate / pathology
  • Prostatic Neoplasms / enzymology
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / pathology
  • RNA, Messenger / biosynthesis
  • Stromal Cells / drug effects
  • Stromal Cells / metabolism
  • Stromal Cells / pathology
  • Tumor Cells, Cultured

Substances

  • Androgen Antagonists
  • Azasteroids
  • Isoenzymes
  • RNA, Messenger
  • Dihydrotestosterone
  • 17-N,N-diethylcarbamoyl-4-methyl-4-azaandrostane-3-one
  • Oxidoreductases
  • Cholestenone 5 alpha-Reductase