Genetic polymorphisms of TLR3 are associated with nasopharyngeal carcinoma risk in Cantonese population

Background: Nasopharyngeal carcinoma is endemic in Southern China, displays a strong relationship with genetic susceptibility and associates with Epstein-Barr virus infection. Toll- like receptor 3 (TLR3) plays an important role in the antivirus response. Therefore, we examined the association between TLR3 gene polymorphisms and NPC susceptibility. Methods: We performed a case- control study of 434 NPC cases and 512 healthy controls matched on age, sex and residence. Both cases and controls are of Cantonese origin from Southern China. Genetic variants in TLR3 were determined by polymerase chain reaction (PCR)-based DNA direct sequencing and four SNPs were genotyped in all samples. Results: Our results showed that allele C for SNP 829A/ C increased NPC risk significantly ((p = 0.0068, OR = 1.49, 95% CI: 1.10 - 2.00). When adjusted for age, gender and VCA-IgA antibody titers, the NPC risk was reduced significantly among individuals who carried the haplotype "ATCT" compared to those who carried the most common haplotype "ACCT" (p = 0.0054, OR = 0.028; 95% CI (0.002 - 0.341). Conclusion: The TLR3 polymorphisms may be relevant to NPC susceptibility in the Cantonese population, although the reduction in NPC risk is modest and the biological mechanism of the observed association merits further investigation.