Epstein-Barr Virus Gene Polymorphism In Different Parts Of The Same Nasopharyngeal Carcinoma Patient

Objective:To detect and compare the EBV genotypes and gene polymorphism of EBV strains between carcinoma tissues, TWs (Throat Washings) and peripheral blood monouclear cells (PBMC) of the same nasopharyngeal carcinoma (NPC) patient in order to explore the EBV strains in different parts of the same NPC patient is different or not.Methods:Paraffin-embedded tissue biopsy of the20clinical diagnosed NPC patients were collected and subjected to EBER1ISH screening to identify the EBV positive NPC samples. After screening, paired samples of carcinoma tissues, TWs and PBMC were collected from the EBERl positive samples to extract DNA. PCR along with restriction fragment length polymorphism (RFLP) analysis were used to detect1/2, F/f and C/D type. EBER and EBNA1genes were furthermore amplified for the sequence analysis.Results:â‘ 18cases of20NPC tissue samples were positive for EBER1ISH.â‘¡The genotypes of1/2, F/f and C/D were successfully amplified in17paired samples. The genotypes in carcinoma tissue were identical to those in TWs of the same patient except one in1/2and one in F/f type. Additionally, type1, type F and type C was the main strain in these detected samples.â‘¢EBER and EBNA1genes were successfully amplified in7paired samples of18positive samples, the sequences were identical in carcinoma tissues and TWs of the same patient except2cases in EBER and1case in EBNA1genes. It shows that different parts of the same patient were infected by the same EBV strains in most cases.â‘£Paired samples of carcinoma tissue, TWs and PBMC were successfully amplified only in3patients. The sequences of EBER gene in1and EBNA1gene in2patients were identical in paired samples of the same patient.Conclusion:Different sites of the same individual are infected by the same EBV strains except a few differences in occasional cases, suggesting that TWs samples from NPC patient is significant to provide guidance for EBV analysis that from tumor tissues in the future. However, it is noteworthy that one should be cautious to take TWs for study because of the small differences.