High expression of indoleamine 2,3-dioxygenase gene in prostate cancer

Eur J Cancer. 2008 Oct;44(15):2266-75. doi: 10.1016/j.ejca.2008.05.023. Epub 2008 Jul 9.

Abstract

Arginase 2, inducible- and endothelial-nitric-oxide synthase (iNOS and eNOS), indoleamine 2,3-dioxygenase (IDO) and TGF-beta, might impair immune functions in prostate cancer (PCA) patients. However, their expression was not comparatively analysed in PCA and benign prostatic hyperplasia (BPH). We evaluated the expression of these genes in PCA and BPH tissues. Seventy-six patients (42 BPH, 34 PCA) were enrolled. Arginase 2, eNOS and iNOS gene expression was similar in BPH and PCA tissues. TGF-beta1 gene expression was higher in BPH than in PCA tissues (p=0.035). IDO gene expression was more frequently detectable (p=0.00007) and quantitatively higher (p=0.00001) in PCA tissues than in BPH. IDO protein, expressed in endothelial cells from both BPH and PCA, was detectable in tumour cells in PCA showing evidence of high specific gene expression. In these patients, IDO gene expression correlated with kynurenine/tryptophan ratio in sera. Thus high expression of IDO gene is specifically detectable in PCA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cytokines / genetics
  • Cytokines / metabolism
  • Gene Expression
  • Gene Expression Profiling / methods
  • Humans
  • Immune Tolerance / genetics
  • Indoleamine-Pyrrole 2,3,-Dioxygenase / genetics
  • Indoleamine-Pyrrole 2,3,-Dioxygenase / metabolism*
  • Kynurenine / blood
  • Male
  • Middle Aged
  • Neoplasm Proteins / blood
  • Polymerase Chain Reaction / methods
  • Prostatic Hyperplasia / enzymology
  • Prostatic Hyperplasia / genetics
  • Prostatic Hyperplasia / immunology
  • Prostatic Neoplasms / enzymology*
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / immunology
  • Tryptophan / blood

Substances

  • Cytokines
  • Indoleamine-Pyrrole 2,3,-Dioxygenase
  • Neoplasm Proteins
  • Kynurenine
  • Tryptophan