Role of NQO1 609C>T and NQO2-3423G>A polymorphisms in susceptibility to gastric cancer in Kashmir valley.

NADPH

quinone oxidoreductase 1 (NQO1) and dihydronicotinamide riboside: quinone oxidoreductase 2 (NQO2) are cytosolic enzymes that catalyze reductive activation of carcinogens from cigarette smoke, such as nitrosamines and heterocyclic amines. These enzymes also protect cells against oxidative damage from reactive oxygen species. The present study investigated the associations of genetic variants of NQO1 609C>T and NQO2 -3423G>A polymorphisms with susceptibility to gastric cancer (GC) as well as their interactions with known risk factors in Kashmir valley. A case control study was performed in 303 subjects (108 GC and 195 healthy controls). All subjects were genotyped using polymerase chain reaction-restriction fragment length polymorphism method. Data were statistically analyzed by chi-square test and logistic regression model. The NQO1 609C>T TT genotype and T allele were significantly associated with increased risk for GC, whereas NQO2 -3423G>A polymorphism did not show any association with GC. Also, NQO1 609C>T TT genotype showed significant association with gastric adenocarcinoma. The interaction of NQO1/NQO2 genotypes with high consumption of salted tea, a known risk factor, did not further modulate the risk of GC. In conclusion, NQO1 609C>T polymorphism shows association with GC risk in Kashmir valley.