title: An association between a NQO1 genetic polymorphism and risk of lung cancer.
abstract: NAD(P)H:quinone oxidoreductase (NQO1) is a detoxification enzyme that protects against the regeneration of reactive oxygen species chemically induced by oxidative stress, cytotoxicity, mutagenicity, and carcinogenicity. The protection conferred by NQO1 protein reduces certain environmental carcinogens, such as nitroaromatic compounds, heterocyclic amines, and possible cigarette smoke condensate. The gene coding for NQO1 has a genetic polymorphism (C-->T) at nucleotide position 609 (i.e. amino acid codon 187) of the NQO1 cDNA. This polymorphism was shown to reduce NQO1 enzyme activity, thereby diminishing the protection provided by NQO1. Therefore, we hypothesized that individuals with the variant NQO1 genotype are at higher risk for lung cancer. Using a case-control study, we genotyped the NQO1 variants successfully by PCR-RFLP in 826 lung cancer patients and 826 healthy control subjects matched for age, sex, ethnicity, and smoking status. The frequency of the NQO1 T-allele was statistically significantly different among three ethnic groups (p<0.001). In further analysis of Caucasians, the variant NQO1 genotypes (CT and TT) were associated with a marginally increased lung cancer risk (OR=1.19; 95% CI: 0.95-1.50). The elevated lung cancer risk was only evident in younger individuals (age <62 years old) (OR=1.46; 95% CI: 1.04-2.05), women (OR=1.89; 95% CI: 1.33-2.68), and never smokers (OR=1.80; 95% CI: 1.03-3.13). Furthermore, we found a statistically significant trend in the development of lung cancer at an early age in women with increasing copies of the variant allele (p=0.03). These results suggest that the NQO1 variant genotype may modulate lung cancer risk, especially in younger individuals (age<62), women, and never smokers.
authors.affiliation: Department of Gynecology Oncology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
authors.forename: Salvador J
authors.initials: SJ
authors.lastname: Saldivar
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhao
authors.forename: Lina
authors.initials: L
authors.lastname: Shao
authors.forename: Jie
authors.initials: J
authors.lastname: Lin
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Spitz
authors.forename: Xifeng
authors.initials: X
authors.lastname: Wu
mesh_terms: D001483:Base Sequence; D016022:Case-Control Studies; D017931:DNA Primers; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D017931:DNA Primers; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human