Objective: To explore the association between HLA-DQA1 gene copy number polymorphisms and gastric cancer risk in Chinese population, and the interaction of those genes and environmental factors.
Methods: The genotype of HLA-DQA1 gene copy number polymorphisms was determined in 343 patients with gastric cancer and 330 controls by quantitative polymerase chain reaction. Logistic regression model was used to evaluate the impact of this polymorphism on the risk of developing gastric cancer and the gene-environment interaction.
Results: Compared with 0 copy of HLA-DQA1 gene carriers, the 2 copies of HLA-DQA1 gene carriers had a significantly increased risk of gastric cancer (OR = 1.87, 95%CI = 1.15 - 3.06, P = 0.012). Gene-environment interaction of HLA-DQA1 gene copy number polymorphisms and Helicobacter pylori infection significantly increased the risk of gastric cancer in a multiplicative manner, with an OR of 3.89 (95%CI = 1.75 - 8.57, P = 0.001).
Conclusions: HLA-DQA1 gene copy number polymorphism is associated with gastric cancer susceptibility, and there is a multiplicative gene-environment interaction between this polymorphism and Hp infection in the development of gastric cancer.