Insulin receptor expression by human prostate cancers

Prostate. 2009 Jan 1;69(1):33-40. doi: 10.1002/pros.20852.


Background: Although recent laboratory and population studies suggest that prostate cancer may be responsive to insulin, there is a gap in knowledge concerning the expression of insulin receptors on benign or malignant prostate tissue.

Methods: We immunostained 644 cores on tissue microarrays prepared from 29 prostate tissue samples without malignancies, 78 Gleason grade 3 cancers, 21 Gleason grade 4 cancers and 33 Gleason grade 5 cancers with antibodies against the insulin-like growth factor I receptor and the insulin receptor.

Results: We observed immunoreactivity with both antibodies, which implies the presence of hybrid receptors as well as IGF-I receptors and insulin receptors. Insulin receptor staining intensity was significantly (P < 0.001) higher on malignant than benign prostate epithelial cells. Analysis of information from public gene expression databases confirmed that co-expression of insulin receptor mRNA and IGF-I receptor mRNA is common in prostate cancer specimens. RT-PCR methods provided evidence for the presence of mRNA for both IR-A and IR-B insulin receptor isoforms.

Conclusion: These observations document the presence of insulin receptors on primary human prostate cancers. The findings are relevant not only to ongoing clinical trials of drug candidates that target IGF-I and/or insulin receptors, but also to the hypothesis that obesity-associated hyperinsulinemia mediates the adverse effect of obesity on prostate cancer prognosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibody Specificity
  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Hyperinsulinism / metabolism
  • Hyperinsulinism / pathology
  • Hyperinsulinism / physiopathology
  • Immunohistochemistry
  • Liver Neoplasms
  • Male
  • Metabolic Syndrome / metabolism
  • Metabolic Syndrome / pathology
  • Metabolic Syndrome / physiopathology
  • Obesity / metabolism
  • Obesity / pathology
  • Obesity / physiopathology*
  • Oligonucleotide Array Sequence Analysis
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / physiopathology*
  • RNA, Messenger / metabolism
  • Receptor, IGF Type 1 / genetics
  • Receptor, IGF Type 1 / immunology
  • Receptor, IGF Type 1 / metabolism
  • Receptor, Insulin / genetics*
  • Receptor, Insulin / immunology
  • Receptor, Insulin / metabolism*
  • Signal Transduction / physiology


  • RNA, Messenger
  • Receptor, IGF Type 1
  • Receptor, Insulin