Abstract: Objective：To explore the expression of clusterin in testicular seminoma tissues. Methods：Tumor tissues were collected from 13 patients with testicular seminoma, and normal testis tissues (as control group) from 16 patients undergoing surgical castration for prostate cancer. Immunohistochemical analysis was performed to compare qualitatively the expression of clusterin in seminoma tissues and control. Real-time polymerase chain reaction（PCR） and western blot analysis were performed to detect quantificationally the expressions of clusterin mRNA and clusterin protein in two groups. Results：The expression of clusterin mRNA in testicular seminoma was significantly lower than that in control group（only 13% of normal tissue）. Analogously, the expression of clusterin protein in testicular seminoma was significantly lower than that in control group. Clusterin expression was mainly located in the Leydig cells, Sertoil cells and maturated spermatogenic cells of normal testes, while there was less expression in seminoma tissues. Conclusions：There were heterodimeric secretory isoforms of clusterin in testicular seminoma and normal testis. The expression of clusterin in testicular seminoma is significantly lowered.

Key words: Clusterin, Testicular neoplasms, Gene expression, Polymerase chain reaction, Blotting, western, Immunohistochemistry