The correlation between polymorphisms of Toll-like receptor 2 and Toll-like receptor 9 and susceptibility to gastric cancer

Abstract

To explore the relationship between the polymorphisms of Toll-like receptor 2 (TLR2) and TLR9 and the susceptibility to gastric cancer. A population-based case-control study was conducted at Linqu county, Shandong province, China, including a total of 248 cases of gastric cancer. Another total of 496 age and sex-matched controls were randomly selected from the same cohorts. TLR2 rs3804099 and TLR9 rs187084 were detected by polymerase chain reaction-restriction fragment length polymorphism method. Odds ratios (ORs) and 95% confidence interval (CI) were computed from logistic regression models after adjusting for age, sex, Helicobacter pylori (H. pylori) infection and smoking status. The frequencies of TT, TC and CC genotype on TLR2 rs3804099 in control group were 43.5% (216/496), 46.6% (231/496) and 9.9% (49/496), respectively; whereas those in case group were 53.2% (132/248), 39.9% (99/248) and 6.9% (17/248), respectively. Significant differences in the frequencies of TLR2 rs3804099 were found between case and control groups (χ(2) = 6.665, P = 0.036). It was found that compared with the TT genotype, TC + CC genotype carriers obviously less susceptible to gastric cancer (OR = 0.68, 95%CI: 0.50 - 0.93). Joint effects analysis indicated that the TLR2 rs3804099 TT genotype carriers and H.pylori infectors had higher susceptibility to gastric cancer(OR = 3.42, 95%CI: 2.16 - 5.42), compared with TC + CC genotype carriers and non-H.pylori infection group. The frequencies of TT, TC and CC genotype on TLR9 rs187084 in control group were 33.3% (165/496), 49.0% (243/496) and 17.7% (88/496), respectively; whereas those in case group were 35.9% (89/248), 50.0% (124/248) and 14.1% (35/248), respectively. No significant association with gastric cancer was observed for TLR9 rs187084 polymorphism (χ(2) = 1.684, P = 0.431). Our findings indicate that TLR2 rs3804099 is closely associated with susceptibility to gastric cancer.