Background & objective: A73 gene, one of the primary members in Epstein-Barr virus (EBV) BamHI-A rightward transcripts (BARTs) family, is related to the development of nasopharyngeal carcinoma (NPC). Its mRNA level is elevated in NPC tissues, suggesting that A73 participates in the carcinogenesis of NPC. This study was to explore the polymorphism loci of A73 gene and find its correlation to susceptibility to NPC.
Methods: Nested polymerase chain reaction (PCR) and direct sequencing were used to identify A73 gene polymorphisms in 23 specimens of NPC and 19 throat washing (TW) samples from non-NPC patients. The same methods were also used on additional 54 unitized NPC specimens [carcinoma tissue, matched TW sample and peripheral blood (PB) sample from the same patient], and 48 TW samples and 51 PB samples from healthy Cantonese to detect a polymorphism with high frequency found in previous step. Its distribution among different samples was compared. All sequences were compared with the sequence of B95.8 cells.
Results: Three polymorphisms A157154C, G159188C, and G159209C were identified in A73 gene. Among which, A157154C showed high frequency. The frequency of A157154C was significant higher in PB samples from NPC patients than in those from healthy Cantonese (96.29% vs. 64.70%, P<0.001). Among 54 unitized specimens, 13 cases showed discordances in different tissue origins.
Conclusion: A157154C in A73 gene might be correlated to the occurrence and development of NPC.