Study On The Relationship Between Epstein-Barr Virus And Gastric Carci-nomas

Objective EBV is a tumor-related virus and EBV genome exists in many human malignant tumors, such as Burkitt's lymphoma, NPC, Hodgkin's disease and B lymphocyte carcinoma in immunodifficiency patients. EBV DNA could be detected in 2j?6% gastric carcinomas and in various pathological differentiated gastric carcinomas. To study the relationship between EBV infection and gastric carcinomas, we detected EBV DNA in gastric carcinomas and the corresponding para-carcinomas tissue by PCR-Southern and in situ hybridization. The expression of EBV latent promoter, latent gene and lytic gene in EBV-positive gastric carcinomas was detected by RT-PCR and Southern blotting.METHOD PCR-Southern was used to detect specific EBV DNA segment,BamH- I W, in 172 gastric carcinomas and the corresponding para-carcinomas. EBER1 of the PCR positive specimens was detected by in situ hybridization to confirm EBV infection. RT-PCR and Southern blotting were used to detect the expression of EBV nuclear antigens' gene promoter (Qp, Cp and Wp), latent gene (EBNA1, EBNA2, LMP1, LMP2A and LMP2B) and lytic gene (BZLF1, BRLF1, BARF1, BHRF1, BcLFl and BLLF1) in EBV-positive gastric carcinomas.RESULT 11 of 172 gastric carcinomas were EBV positive. There was no significant statistic difference between EBV-positive and EBV-negative gastric carcinomas in age, sex, pathological differentiation or clinical stages (P = 0. 069,0. 485,0. 237 and 0. 151 respectively). EBV genome was not detected in the corresponding para-carcinomas and there was significant statistic difference between gastric carcinomas and the corresponding para-carcinomas in EBV positive rate (P = 0. 0026). Of the 11 EBV-positive gastric carcinomas, Qp was all positive expression while both Cp and Wp were negative expression. Of the latent gene, all the 11 EBV-positive gastric carcinomas expressed EBNA1 but none of them expressed EBNA2, LMP1 and LMP2B. To our surprise, 4 of the 11 EBV-positive gastric carcinomas expressed LMP2A. Of the lytic gene, part of the 11 EBV-positive gastric carcinomas expressed different type of lytic gene.CONCLUSION (1)The positive rate of EBV infection in gastric carcinomas is 6. 39% and there is no significant statistic differentce between EBV-positive and EBV-negativegastric carcinomas in age, sex, pathological differentiation or clinical stages. (2)EBV genome was not detected in the corresponing para-carcinomas and there is significant statistic difference between gastric carcinomas and the corresponding para-carcinomas in EBV positive rate, which indicates that there is a certain relationship between EBV infection and gastric carcinomas. (3)EBNA1 was transcripted from Qp and EBV latent type in gastric carcinomas was between type I and type II. (4)Part of the EBV-positive gastric carcinomas were EBV lytic infection.