Genetic variant of the p22PHOX component of NADPH oxidase C242T and the incidence of gastric cancer in Japan.

BACKGROUND/AIMS: Reactive oxygen species has been implicated in the development of gastric cancer. NADPH oxidase, a major source of superoxide generation play a critical role in H. pylori related gastric inflammation. We aimed to clarify the effect of C242T polymorphism of p22PHOX, an essential component of NADPH oxidase on the risk of gastric cancer, gastric ulcer and duodenal ulcer in a Japanese population. MATERIALS AND METHOD: 376 gastric cancer patients and 436 cancer-free subjects participated in this study. The p22PHOX C242T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: In the non-cancer subjects, the p22PHOX genotype distribution was 365CC (83.7%), 63CT (15.4%), and 4TT (0.9%). Meanwhile, the p22PHOX genotype distribution in gastric cancer was 311CC (82.7%), 63CT (16.8%), and 2TT (0.5%). There was no significant difference between two groups in the distribution of T carrier frequency (OR=1.04, 95% CI=0.71-1.53). No association was also observed between p22PHOX genotypes and Lauren's classification, tumor stage and anatomical locations. CONCLUSION: It appears that the C242T polymorphism of p22PHOX is not associated with the incidence of gastric cancer in the Japanese population.