Presence of 5alpha-reductase isozymes and aromatase in human prostate cancer cells and in benign prostate hyperplastic tissue

Prostate. 1998 Mar 1;34(4):283-91. doi: 10.1002/(sici)1097-0045(19980301)34:4<283::aid-pros6>;2-i.


Background: Prostate trophism depends on DHT formed from T by the enzyme 5alpha-R. Two 5alpha-R isoforms with different biochemical characteristics have been cloned. Also estrogens might contribute to the prostate growth; however, their intraglandular formation by the enzyme aromatase is still debated. The aim of the present study was to verify whether (a) only one or both isoforms of the 5alpha-Rs are expressed in the prostate cancer cell line LNCaP and in BPH, or (b) the aromatase is present in these samples.

Methods: The profile of the pH optimum of the 5alpha-Rs was evaluated "in vitro" in LNCaP cells by the production of labeled 5alpha-reduced metabolites either from [14C]-T or [14C]-D4 at pH 3.5-8. The gene expression of the two 5alpha-Rs and of the aromatase in LNCaP cells and in BPH specimens was analyzed by RT-PCR combined to Southern blot analysis, using specific sets of oligonucleotides. The tissue localization of 5alpha-R1 was analyzed by immunohistochemistry using an anti-5alpha-R1 polyclonal antibody.

Results: (a) In LNCaP cells, the formation of 5alpha-reduced metabolites from the respective precursors increases progressively as a function of pH, being the highest at neutral pH values; (b) the 5alpha-R1 isoform is expressed in both LNCaP cells and in BPH, while the 5alpha-R2 mRNA is present only in BPH, but not in LNCaP cells; and (c) no aromatase transcripts were observed either in BPH or in LNCaP cells.

Conclusions: A careful examination of the possible differential expression of T-activating enzymes, particularly in prostate cancer, would be of help to choose the appropriate treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / biosynthesis*
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / genetics
  • Animals
  • Aromatase / biosynthesis*
  • Aromatase / genetics
  • Humans
  • Isoenzymes / biosynthesis*
  • Isoenzymes / genetics
  • Male
  • Prostatic Hyperplasia / enzymology*
  • Prostatic Hyperplasia / pathology
  • Prostatic Neoplasms / enzymology*
  • Prostatic Neoplasms / pathology
  • Rabbits
  • Tumor Cells, Cultured


  • Isoenzymes
  • Aromatase
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase