IL-6, IL-10 and HSP-90 Expression in Tissue Microarrays from Human Prostate Cancer Assessed by Computer-assisted Image Analysis

Abstract

The interleukins (IL)-6 and -10 and heat shock proteins (HSP) have an important role in the host-tumor interaction and in tumor bulk. HSP-90 may have a regulatory role in cytokine biosynthesis and prognostic value in some tumors. To define the role of IL-6, IL-10 and HSP-90 in prostate cancer progression the immunohistochemical expressions of these proteins were analyzed in 168 prostatic carcinomas. IL-6, IL-10 and HSP-90 immunoreactivity was higher in prostatic carcinoma (CaP) and intra-epithelial prostatic neoplasia (PIN) than in normal prostatic tissue (NAP) adjacent to neoplasia. In the epithelium, IL-6, IL-10 and HSP-90 expressions increased from NAP to PIN to CaP. In the stroma, IL-6 and IL-10 expressions decreased significantly from NAP to PIN to CaP (p<0.01 by Chi-square test), while HSP-90 expression increased. In the epithelium of PIN and CaP, IL-6 immunoreactivity was significantly lower than IL-10 and HSP-90. In neoplastic acini HSP-90 levels were significantly higher than those of IL-6 and IL-10 (p<0.01 by Chi-square test). In the stroma of NAP and PIN, but not of CaP, HSP-90 immunoreactivity was significantly lower than that of IL-6 and IL-10 (p<0.01). Our results indicate that the IL-6 and IL-10 cytokine balance differs in pathological and normal prostate, thus suggesting that certain cytokines are specific to the neoplastic prostate. Changes in the expressions of IL-6, IL-10 and HSP-90 in human prostate carcinoma samples could be used as a prognostic marker of disease progression.