Contribution of interaction between genetic variants of interleukin-11 and Helicobacter pylori infection to the susceptibility of gastric cancer

BACKGROUND: Gastric cancer (GC) ranks the second leading cause of cancer-related mortality worldwide. We aimed to clarify the relevance of genetic variants of IL-11, a hub of various carcinogenic pathways, as well as their interactions with Helicobacter pylori (H. pylori) infection in the development of GC. METHODS: A case–control study with 880 GC cases and 900 healthy controls was conducted in a Chinese population. Six tagSNPs were detected by Taqman Allelic Discrimination assay, while H. pylori status was detected by Typing Detection Kit for Antibody to H. pylori and serum IL-11 level was measured using ELISA method. RESULTS: We found that rs1126760 (C vs T: OR=1.39, 95% CIs=1.13–1.70, P=0.002) and rs1126757 (C vs T: OR=0.82, 95% CIs=0.72–0.93, P=0.002) were significantly associated with susceptibility of GC. Even adjusted for Bonferroni correction, the results were still significant (P=0.002×6=0.012). IL-11 rs1126760 was significantly associated with higher serum and expression level of IL-11, while rs1126757 was significantly associated with lower serum IL-11 level (P<0.001). Significant interaction with H. pylori infection was identified for rs1126760 (P for interaction =0.005). Higher expression of the IL-11 gene was significant with development and poor prognosis of GC. CONCLUSION: Our study provides strong evidence that genetic variants of the IL-11 gene may interact with H. pylori infection and contribute to the development of GC. Further studies with larger sample size and functional experiments are needed to validate our findings.