Expression Of Galanin And Galanin2 Receptors In Prostate Tissue And Its Clinical Significance

Objective:To study the expression and significance of Galanin and Galanin receptor2(GalR2) in benign and malignant tumors of prostate and to investigate its relationship with clinical practice.Methods:50specimens of benign prostate hyperplasia(BPH),50of prostate carcinoma without metastasis(PCa) and30of prostate carcinoma with bone metastasis(BM) were analyzed using immunohistochemical staining with anti-Galanin antibody and anti-GalR2antibody, respectively, followed with clinicopathological significance analysis. Cell lines of human prostate hyperplasia BPH-1and of human prostate cancer DU145were selected in this study. After the process of cell culture and total cell protein extraction, Western blotting was operated to detect the expression of Galanin and GalR2protein in these two cell lines, respectively.Results:Immunohistochemistry showed that the positive expression of Galanin is9/50in BPH,34/50in PCa, and25/30in BM; and the positive expression of GalR2is40/50in BPH,7/50in PCa, and2/30in BM. The expression of Galanin in PCa and in BM were significantly higher than that in BPH, respectively (x2=25.50, P<0.01; x2=32.75, P<0.01), there was no significant difference of Galanin expression between PCa and BM(x2=2.28, P>0.05); however, the expression of GalR2in BPH was significantly higher than that in PCa and BM, respectively (χ2=43.72, P<0.01;χ2=40.43, P<0.01); there was no significant difference of GalR2expression between PCa and BM(x2=1.01, P>0.05). In PCa and BM, respectively, Galanin expression were all significantly negatively associated with GalR2expression (rs=-0.55, P<0.01; rs=-0.77, P<0.01). The results of Western blotting showed that the expression of Galanin protein was significantly reduced in BPH-1cells, while was significantly increased in DU145cells expressing increased; on the contrary, the expression of GalR2protein was increased in BPH-1cells, while was reduced in DU145cells. This result is consistent with the results of immunohistochemistry.Conclusions:Galanin was highly expressed in prostate carcinoma, indicating that Galanin protein may involve in the process of tumor pathogenesis; while GalR2showed low expression in prostate carcinoma, and negative correlation with Galanin expression in the results of immunohistochemistry, which both indicated that, in pathogenesis of prostate carcinoma, Galanin may play biological roles via other receptors, but GalR2. Furthermore, in clinical practice, combining the detections of Galanin and GalR2could help better diagnosis of benign or malignant prostate tumor.