Toll-Like Receptor Gene Polymorphisms and Susceptibility to Epstein–Barr Virus-Associated and -Negative Gastric Carcinoma in Northern China

BACKGROUND/AIMS: Various polymorphisms in toll-like receptor (TLR) genes have been identified and associated with susceptibility to various malignancies, such as gastric carcinoma (GC), breast cancer, and prostate cancer. However, little is known about the polymorphisms of TLR genes and the susceptibility to GC in Northern China, especially to Epstein–Barr virus-associated GC (EBVaGC). We focused on the association with susceptibility to GC, especially to EBVaGC. PATIENTS AND METHODS: Polymorphisms of the TLR2, 3, 4, and 9 genes were measured in 52 cases of EBVaGC and 157 cases of EBV-negative GC (EBVnGC). Ninety-four peripheral blood samples from healthy individuals were also examined. RESULTS: For the TLR2 gene (196 to 174 del), there was no significant difference between the GC group and control group in genotype, but there was a significant difference in the del allele. As for the TLR3 gene (c. 1377C/T), there were significant differences between the GC group and the control group in both genotype and allelic frequency. No SNPs single nucleotide polymorphisms (SNPs) were found in the TLR4 gene at the sites Asp299Gly and Thr399Ile. As for TLR9 1486T/C (rs187084) and C2848T (rs352140), there was also no association between the GC group and control. In all of the indicators, there were no significant differences between EBVaGCs and EBVnGCs. CONCLUSIONS: The TLR3 gene (c. 1377C/T) polymorphisms and the del allele of the TLR2 gene (196 to 174) were both associated with susceptibility to GC in Shangdong Province of Northern China. There was no interaction between EBV and TLR gene polymorphisms in EBVaGC.