Association between NQO1 C609T polymorphism and colorectal cancer risk

The Analysis of NADPH Quinone Reductase 1 (NQO1) Polymorphism in Polish Patients with Colorectal Cancer

Colorectal cancer (CRC) is one of the most common malignancies in Poland. Based on the findings of clinical trials, it is safe to conclude that genetic predisposition and environmental factors are the main factors responsible for the formation of colorectal cancer.The NQO1 gene plays an important role in reducing endogenous and exogenous quinones as well as quinone compounds to hydroquinones. It is an enzyme which is a part of the body’s antioxidant defense system. The aim of the study was to evaluate the correlation between the 609C > T polymorphism of the NQO1 gene and colorectal cancer risk in the Polish population. A total of 512 people were recruited for the study, including 279 patients with colorectal cancer, diagnosed at the University Hospital, Pomeranian Medical University in Szczecin. Genomic DNA was isolated from peripheral blood and the analyzed polymorphism was determined by PCR-RFLP. In the present study, we analyzed the clinical valuesand frequency of NQO1 609C > T polymorphism in patients diagnosed with colorectal cancer and controls. In case of the carriers of the TT genotype of the NQO1 polymorphism, an elevated risk for colorectal cancer was observed (OR = 2.96; 95% CI: 1.02–10.40). The analysis of the clinical parameters concerning the location and characteristics of the tumor stage revealed a statistically significant increase in the risk for colorectal cancer in the carriers of the TT genotype of the NQO1 polymorphism.

Evaluating the predictive value of genetic risk score in colorectal cancer among Chinese Han population

Increasing single nucleotide polymorphisms (SNPs) have been identified to be associated with colorectal cancer (CRC). We aimed to investigate whether genetic risk scores (GRS) that aggregate information from multiple genetic variants can predict the risk of CRC in a Chinese population. Fifty candidate SNPs were selected to explore the associations with CRC in a discovery sample with 1002 CRC cases and 999 healthy controls. We modeled the significant SNPs identified by the case-control study as a multilocus weighted GRS and estimated the association of GRS with CRC. Furthermore, 300 pairs of cases and controls were included as a validation sample to confirm the finding. Area under the receiver operating characteristic curve (AUROC) was used to evaluate the predictive power of GRS in CRC. A total of seven SNPs were found to increase the risk of CRC, and two SNPs were found to be negatively associated with CRC in the discovery sample. Relative to participants with the lowest quartile of GRS, those with the highest quartile had a 2.64-fold (95% CI: 1.99-3.51) higher risk for CRC. For every 0.1 point of GRS increase, the risk of CRC increase by 11% (95% CI: 8-14%). AUROC for GRS alone were 0.59 (95% CI: 0.57-0.62) and 0.52 (95% CI: 0.46-0.58) in the discovery and validation sample, respectively. AUROC increased to 0.62 (95% CI: 0.59-0.64) and 0.71 (95% CI: 0.65-0.76) by combining environmental risk factors. Our findings support an association between GRS and risk of CRC, which provides evidence of improved prediction model for CRC in China.

NQO1 C609T polymorphism and colorectal cancer susceptibility: a meta-analysis

INTRODUCTION

A FEW STUDIES HAVE REPORTED AN ASSOCIATION BETWEEN NADP(H): quinine oxidoreductase 1 (NQO1) C609T polymorphism and susceptibility to colorectal cancer (CRC). However, the results were inconsistent rather than conclusive. We performed a meta-analysis to examine this association in various populations.

MATERIAL AND METHODS

Eligible articles were identified by a search of several databases up until June 30, 2013. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of the association.

RESULTS

Overall, 14 case-control studies with 4,461 cases and 5,474 controls were included in this meta-analysis. The results indicated that the NQO1 C609T polymorphism was significantly associated with CRC susceptibility (summary ORs (95% CIs): 1.30 (1.07-1.59) for CT vs. CC, 1.64 (1.15-2.33) for TT vs. CC, 1.34 (1.10-1.64) for TT/CT vs. CC, and 1.43 (1.10-1.87) for TT vs. CT/CC). Subgroup analyses indicated that the T allele was significantly associated with CRC susceptibility in both Asians and Caucasians, and was also observed in high quality studies and hospital-based case-control studies. Specifically, we found a positive association between the NQO1 C609T polymorphism and CRC susceptibility in smokers, but not in non-smokers.

CONCLUSIONS

The results of this meta-analysis suggest that the NQO1 C609T polymorphism significantly contributes to increased susceptibility to CRC in both Asians and Caucasians.

Association between NQO1 Pro187Ser polymorphism and esophageal cancer: a meta-analysis

NAD(P)H

quinone oxidoreductase 1 (NQO1) is an important enzyme which can catalyze the two-electron reduction of quinoid compounds into hydroquinones. NQO1 Pro187Ser polymorphism can change the enzymatic activity of NQO1, and it has been proposed to be associated with risk of esophageal cancer. We performed a meta-analysis to examine the association between NQO1 Pro187Ser polymorphism and esophageal cancer. Odds ratio (OR) with a 95% confidence interval (95% CI) was used to assess the association. Twelve case-control studies with 1,725 cases with esophageal cancer and 2,341 controls were finally included in the meta-analysis. Overall, there was an obvious association between NQO1 Pro187Ser polymorphism and esophageal cancer (allele model: OR = 1.24, 95% CI 1.06-1.46, P OR = 0.009; homozygote model: OR = 1.59, 1195% CI 1.10-2.30, P OR = 0.013; dominant model: OR = 1.31, 95% CI 1.05-1.64, P OR = 0.018). In the subgroup analysis by ethnicity, there was an obvious association between NQO1 Pro187Ser polymorphism and esophageal cancer in Asians but not in Caucasians. Therefore, the meta-analysis suggests that NQO1 Pro187Ser polymorphism is associated with esophageal cancer risk.