INVOLVEMENT OF EPSTEIN-BARR-VIRUS EXPRESSION IN TESTICULAR-TUMORS

Purpose: Because orchitis has been described as a symptom of infectiou s mononucleosis which is caused by Epstein-Barr virus (EBV), a human t umor virus, we tried to ascertain the relationship between EBV and tes ticular tumors. Materials and Methods: Sixteen seminomas, 11 embryonal carcinomas and 25 nonmalignant control testes were examined for persi stence and expression of the EBV genome. To detect expression of EBV, mRNA in situ hybridization and immunofluorescence staining by monoclon al antibodies were performed. To confirm the EBV genome in testes, we used nested polymerase chain reaction (PCR). Results: Messenger RNA in situ hybridization showed that all 27 seminomas and embryonal carcino mas expressed EB viral RNA, but the 25 nonmalignant testes did not. Mo noclonal antibody staining showed EBV-related nuclear antigen (EBNA) 2 and latent membrane protein (LMP) 1 expression in testicular tumors. Nested polymerase chain reaction detected the EBV genome in normal tes tes as well as in testicular tumors. Conclusions: These results sugges t that EBV is related to testicular tumors.