Overexpression Of TGM4and Prostate Cancer Progression：a Potential Predictor Of Biochemical Recurrence

Background Transglutaminase4(TGM4), which predominantly expressed in prostategland, is one member of the family of transglutaminases which catalyze thepost-translational modification of proteins by the formation of ε-(γ-glutamyl) lysineisopeptide bonds. Previous studies indictated that TGM4was differentially expressedbetween normal prostate tissue and prostate cancer and improve various biologicalproperties of prostate cancer cells, e.g. cell-matrix adhesion, invasiveness andepithelial-mesenchymal transition. The objectives of the study were to investigate theassociation of TGM4expression with established features of prostate cancer as well asbiochemical recurrence (BCR) in patients treated with radical prostatectomy (RP).Methods TGM4immunostaining was performed on a tissue microarray, which containedspecimen cores from160patients treated with RP for prostate cancer. The expression ofTGM4was evaluated by a scoring method based on the intensity of scoring and extent ofstaining. The clinical and pathological information was obtained through review of medicalrecords. Follow-up data was obtained through consulting the hospital medical records andthe prostate cancer database of our department, contacting with the patients or the familymembers. We then compared the transglutaminase4expression between prostate cancertissue and para-carcinoma tissue, followed by evaluation of the correlation oftransglutaminase4expression and clinical parameters and biochemical recurrence ofprostate cancer.Results The staining of TGM4is significantly higher in tumor tissue than inpara-carcinoma tissue (p<0.001) and positively associated with high Gleason score(p<0.001) and prostate specific antigen (PSA) level (p=0.005). Patients with TGM4over-expression were at increased risk of BCR after surgery (p=0.042) in univariateanalysis but not in multivariate analysis (p=0.139).Conclusions The expression of TGM4increased in tumor tissue which is associated withhigher Gleason score and PSA level, and the overexpression of TGM4may be served as apotential predictor of BCR.