Immunohystochemical analysis of SOCS3 in prostatic adenocarcinoma biopsies.

Abstract

e15132 Background: Chronic inflammation and the subsequent tissutal alterations may play a key role in prostate carcinogenesis. Molecular alterations of the suppressor of cytokine signaling (SOCS)3, can contribute to explain the pleiotropic role of interleukin (IL)-6 in this type of cancer. In a recent study, we demonstrated that methylation of SOCS3 may be involved in the pathogenesis of prostate cancer and could identify in a subset of tumor with an aggressive behavior. Methods: We analyzed the protein expression of SOCS3 by immunohistochemistry in 50 prostate cancer biopsies: 30 prostatic carcinoma with Gleason score 7, 10 with Gleason score <7 and 10 with Gleason score >7. Slides were incubated with monoclonal antibody SOCS3 (1E4) (1.5 mg/ml; Abnova, Taiwan). The SOCS3 staining intensity were evaluated by two pathologist (FP and LML) in three different way: positive; negative; weak intensity staining with negative neoplastic glands. Colonic mucosa were used as positive control. Results: SOCS3 positive were found in all cases of adenocarcinoma Gleason score < 7 and in 10 cases with Gleason score 7, negative staining were found in all cases of adenocarcinoma Gleason score > 7 and in 8 cases with Gleason score 7. Weak SOCS3 staining with presence of negative neoplastic glands were found in 12 cases of adenocarcinoma Gleason score 7. The group of tumor SOCS3 negative were significantly more aggressive than group SOCS3 positive in terms of TNM stage,positivity of surgical margin. Cases with weak SOCS3 staining and negative neoplastic glands displayed more aggressive clinical behavior than cases SOCS3 positive (increase number of T3a and positive surgical margins), on the other hand unlike SOCS3 negative no stage T3b and lymphnode metastasis were found. Conclusions: Immunohystochemical analysis of SOCS3 protein unlike methylathion study identify three different groups of tumors: positive, negative and with weak SOCS3 staining with the presence of negative neoplastic glands. In this last group the reduction of expression protein and the presence of negative neoplastic glands could indicate an intermediate stage of tumor turning towards shutdown of SOCS3 and thus object of strict follow-up and suitable to demethylating agents therapy.