Objective: To investigate the relationship between polymorphism of NAD(P)H quinone oxidoreductase 1 (NQO1) and X-ray repair cross-complementing group1 (XRCC1) and their correlation with smoking on the susceptibility to gastric cancer.
Methods: A 1:1 case-control study of 334 patients with primary gastric cancer, with non-cancer or alimentary inpatients as control group (matched for ages ± 5 years, sex and region) in Anhui province was conducted to analyze the NQO1(C609T) and XRCC1(G28152A). Gene types by PCR-based restriction fragment length polymorphism techniques. Interaction index (γ) was calculated to determine the type of gene-environment interaction.
Results: The average age of 334 cases of gastric cancer patients was 57 years, with 65.3% of them were male. Smoking rate in the case group (55.09%) was significantly higher than in the control group (36.53%). The consequence showing that it carried the heterozygous variant (CT) or homozygous variant (TT) of NQO1 could enhance the risk of gastric cancer (OR = 1.507, 3.050), but not the XRCC1(G28152A) gene polymorphism or the susceptibility to gastric cancer. At the same time, individuals that carrying XRCC1AG and NQO1TT could increase 2.789 times the incidence of gastric cancer than those who carrying the XRCC1AG or NQO1CC. The gastric cancer risk of XRCC1GG individuals that carrying NQO1TT was 4.448 times higher than those who carrying XRCC1GG or NQO1 CC. The positive interactions of NQO1 homozygous variant (TT), XRCC1 homozygous variant (GG) and smoking were revealed in the occurrence rates of gastric cancer (OR=3.094, γ=2.070).
Conclusion: Our research findings showed that the significant interactions between genetic polymorphisms of NQO1, XRCC1 and smoking added the risk of gastric cancer, while genetic and environmental hazardous factors co-effecting the development of gastric cancer.