Association of EBV EBNA1 C-terminal variations with severity of Invasive ductal carcinoma.

BACKGROUND: Breast cancer is a major cause of mortality, and Epstein-Barr virus (EBV) is considered a potential contributor to cancer development. EBV nuclear antigen 1 (EBNA1) plays a vital role in viral persistence. This study aimed to investigate the association among EBNA1 C-terminal variations and severity of invasive ductal carcinoma (IDC). METHOD: A total of 60 female participants, were included in this study. EBV positive biopsy samples (N = 30) were obtained from the breast cancer patients while 30 healthy females served as control. The C-terminal region of EBNA1 gene was amplified and sequenced. Statistical analysis was carried out using SPSS v25. RESULT: Among the breast cancer patients, 97% had IDC and 3% had ductal carcinoma in situ. Regarding tumor grade, 3% of the patients had grade I, 63% had grade II and 33% had grade III tumors. The P-Thr (70%) and its co-infection with V-leu (30%) were observed predominantly in patients with higher grade; however, no significant association was observed. A total of 15 consensus single-nucleotide polymorphisms were observed along with six random mutations. No significant association was reported among random SNPs with breast cancer severity. Phylogenetic analysis shows that our sequences of P-Thr exhibited high similarity with reference sequence NC_009334. All control samples were EBV negative. CONCLUSION: P-Thr was the predominant EBNA1 prototype in study population. However, no significant association was found between EBNA1 variations with breast cancer severity.