Interleukin-6 is an autocrine growth factor in human prostate cancer

Am J Pathol. 2001 Dec;159(6):2159-65. doi: 10.1016/S0002-9440(10)63067-2.


Prostate cancer is the most common cancer in American men and the second leading cause of cancer deaths in this group. We have found that interleukin (IL)-6 protein concentrations are increased approximately 18-fold in clinically localized prostate cancers when compared to normal prostate tissue. Normal and neoplastic prostatic epithelial cells in culture, with the exception of LNCaP cells, secrete IL-6. Addition of exogenous IL-6 to primary epithelial cells in culture or the LNCaP prostate cancer cell line leads to phosphorylation of Stat-3 and increases in net cell proliferation. The concentration of IL-6 receptor is increased eightfold in the prostate cancer tissues and is increased in the cancer cells by immunohistochemistry. The increased expression of IL-6 receptor is correlated with increased proliferation of prostate cancer cells in vivo as assessed by Ki67 immunohistochemistry. These findings strongly support the hypothesis that IL-6 acts as a significant autocrine growth factor in vivo for primary, androgen-dependent prostate cancers.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Division / drug effects
  • DNA-Binding Proteins / metabolism
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Growth Substances / metabolism
  • Humans
  • Immunohistochemistry
  • Interleukin-6 / metabolism*
  • Interleukin-6 / pharmacology
  • Male
  • Phosphorylation
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology*
  • Receptors, Interleukin-6 / metabolism
  • STAT3 Transcription Factor
  • Time Factors
  • Trans-Activators / metabolism
  • Tumor Cells, Cultured


  • DNA-Binding Proteins
  • Growth Substances
  • Interleukin-6
  • Receptors, Interleukin-6
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Trans-Activators