title: Interleukin-6 is an autocrine growth factor in human prostate cancer.
abstract: 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.
authors.affiliation: Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: D
authors.initials: D
authors.lastname: Giri
authors.forename: M
authors.initials: M
authors.lastname: Ozen
authors.forename: M
authors.initials: M
authors.lastname: Ittmann
mesh_terms: D002455:Cell Division / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D019947:Receptors, Interleukin-6 / Q000378:metabolism; D050796:STAT3 Transcription Factor; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D004268:DNA-Binding Proteins; D006133:Growth Substances; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators