Contribution of NAD(P)H quinone oxidoreductase 1 (NQO1) Pro187Ser polymorphism and risk of colorectal adenoma and colorectal cancer in Caucasians: a meta-analysis

Impacts of some clinicopathodemography and colorectal tissues key cell cycle and mucin stabilizing molecules on the metastasis trend in colorectal cancer patients

BACKGROUND

We aimed to evaluate the various clinicopathodemographical, epidemiological, and molecular contributors to cumulatively worldwide metastatic colorectal cancer (CRC) in CRC patients from a highly populated area in northeastern Iran to pinpoint metastasis risk.

METHODS

A retrospective clinical material-based cohort including a total of 6260 registered CRC patients, of whom 3829 underwent surgery, from regional university hospitals, during 2006-2016, were analyzed for the clinicopathodemographical aspects of age, sex, stage of CRC, history of smoking, type 2 diabetes (T2D), hypertension, body mass index (BMI), familial/occupational status, post-surgery survival period and mRNA/protein expression of mucin stabilizer (B3GALNT2), mucin I (MUC1), key cell cycle molecules (i.e., P53 and Ki67), and MMR-related genes. Factors were set to estimate the risk of metastatic CRC and mortality.

RESULTS

Predominant adenocarcinomatous CRCs were found in colon. Post-surgery survival period of metastatic CRC patients was remarkably longer in patients aged > 50 compared to those aged < 50 years, and worse in females than males. B3GALNT2high, MUChigh, P53low, and Ki67high mRNA/protein expression in the metastatic stage III CRC along with T2D and hypertension were associated with increased metastasis/mortality, with more worsening in males, older, BMI > 25, urban residing, and employed individuals, indicative of non-genetic attributable factors.

CONCLUSION

B3GALNT2, MUC1, and "Ki67" can be used as promising biomarkers for prognosis and early diagnosis of increasingly/predominantly non-genetic/environmental originated metastatic CRCs.

The diverse functionality of NQO1 and its roles in redox control

In this review, we summarize the multiple functions of NQO1, its established roles in redox processes and potential roles in redox control that are currently emerging. NQO1 has attracted interest due to its roles in cell defense and marked inducibility during cellular stress. Exogenous substrates for NQO1 include many xenobiotic quinones. Since NQO1 is highly expressed in many solid tumors, including via upregulation of Nrf2, the design of compounds activated by NQO1 and NQO1-targeted drug delivery have been active areas of research. Endogenous substrates have also been proposed and of relevance to redox stress are ubiquinone and vitamin E quinone, components of the plasma membrane redox system. Established roles for NQO1 include a superoxide reductase activity, NAD+ generation, interaction with proteins and their stabilization against proteasomal degradation, binding and regulation of mRNA translation and binding to microtubules including the mitotic spindles. We also summarize potential roles for NQO1 in regulation of glucose and insulin metabolism with relevance to diabetes and the metabolic syndrome, in Alzheimer's disease and in aging. The conformation and molecular interactions of NQO1 can be modulated by changes in the pyridine nucleotide redox balance suggesting that NQO1 may function as a redox-dependent molecular switch.

Systematic meta-analyses and field synopsis of genetic association studies in colorectal adenomas

BACKGROUND

Low penetrance genetic variants, primarily single nucleotide polymorphisms, have substantial influence on colorectal cancer (CRC) susceptibility. Most CRCs develop from colorectal adenomas (CRA). Here we report the first comprehensive field synopsis that catalogues all genetic association studies on CRA, with a parallel online database [http://www.chs.med.ed.ac.uk/CRAgene/].

METHODS

We performed a systematic review, reviewing 9750 titles, and then extracted data from 130 publications reporting on 181 polymorphisms in 74 genes. We conducted meta-analyses to derive summary effect estimates for 37 polymorphisms in 26 genes. We applied the Venice criteria and Bayesian False Discovery Probability (BFDP) to assess the levels of the credibility of associations.

RESULTS

We considered the association with the rs6983267 variant at 8q24 as 'highly credible', reaching genome-wide statistical significance in at least one meta-analysis model. We identified 'less credible' associations (higher heterogeneity, lower statistical power, BFDP > 0.02) with a further four variants of four independent genes: MTHFR c.677C>T p.A222V (rs1801133), TP53 c.215C>G p.R72P (rs1042522), NQO1 c.559C>T p.P187S (rs1800566), and NAT1 alleles imputed as fast acetylator genotypes. For the remaining 32 variants of 22 genes for which positive associations with CRA risk have been previously reported, the meta-analyses revealed no credible evidence to support these as true associations.

CONCLUSIONS

The limited number of credible associations between low penetrance genetic variants and CRA reflects the lower volume of evidence and associated lack of statistical power to detect associations of the magnitude typically observed for genetic variants and chronic diseases. The CRA gene database provides context for CRA genetic association data and will help inform future research directions.

Clinical Significance of the NQO1 C609T Polymorphism in Non Small Cell Lung Adenocarcinoma Patients

NAD(P)H

quinone oxidoreductase 1 (NQO1) is part of the antioxidant defence system involved in detoxification. This study aimed to analyze the influence of NQO1 (C609T) genetic polymorphism in non small cell lung cancer (NSCLC)as a putative risk factor.

MATERIALS AND METHODS

Present study included 100 cases of NSCLC (adenocarcinoma) patients and 100 age and sex matched healthy controls. NQO1 (C609T) genotyping was performed by allele specific PCR for assessment of putative associations with clinical outcome and genotypes of. The association of the polymorphism with the survival of NSCLC patients' was analyzed by Kaplan-Meier method.

RESULTS

In Indian NSCLC (adenocarcinoma) patients increased risk of developing NSCLC was found to be associated with NQO1 609TT genotype [OR 3.68(0.90-14.98), RR 2.04(0.78-5.31)] for CT [OR 2.91(1.58- 5.34), RR 1.74(1.23-2.44) p= 0.0005 for CT], for CT+TT [ OR 3.26(1.82-5.82), RR 1.87(1.34-2.61) p<0.0001 for CT+TT]. A significant difference (p=0.0009) was observed in genotype distribution among cases and healthy controls. Patients with CT+TT genotype exhibited a significant poor overall survival compared with patients displaying homozygous CC genotype (p=0.03) and when survival independently compared with CC, TT and CT genotype was also found to be significantly associated (p=0.02). Overall median survival times were CT 6.0 months, TT 8.2 months, and CT + TT (6.4 months)].

CONCLUSIONS

The present study revealed that NQO1 CT, TT and CT+TT genotypes may be associated with clinical outcome and risk of developing NSCLC in the Indian population.

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.

Effect of NQO1 C609T polymorphism on prostate cancer risk: a meta-analysis

Background

Some studies have found that the NAD(P)H:quinone oxidoreductase 1 (NQO1) SNP609 is associated with an increased risk for several malignancies. Numerous epidemiological studies have evaluated the association between the NQO1 C609T polymorphism and the risk of prostate cancer. However, the results of these studies have been conflicting. The aim of this study was to provide a more precise estimation of its relationship with prostate cancer using a meta-analysis.

Methods

Electronic searches of several databases were conducted for all publications on the association between the NQO1 C609T polymorphism and prostate cancer before May 2013. The odds ratio (OR) and its 95% confidence interval (CI) were used for statistical analysis.

Results

A total of six studies with 717 cases and 1,794 controls were included. No significant association was found between the NQO1 C609T polymorphism and prostate cancer risk in the total population analysis. In subgroup meta-analysis by ethnicity, a positive association was found in an Asian subgroup (T versus C, OR 1.337, 95% CI 1.014–1.763, P=0.040; TT + CT versus CC, OR 1.419, 95% CI 1.053–1.913, P=0.021). However, no significant association in any genetic models was observed in Caucasians.

Conclusion

This meta-analysis showed that the NQO1 SNP609 T allele might be a risk factor for prostate cancer in Asians. However, this result should be verified by additional population-based studies with large sample sizes.

Genetic polymorphism 609C>T in NAD(P)H:quinone oxidoreductase 1 enhances the risk of proximal colon cancer

Gastrointestinal (GI) cancer is responsible for the majority of deaths among all types of cancer. Lifestyle factors may not only be the main risk factor for GI cancer but reactive oxygen species (ROS) may also be involved. The single-nucleotide polymorphisms (SNPs) 609C>T (rs1800566) and 465C>T (rs1131341) in the

NAD(P)H

quinone oxidoreductase 1 (NQO1) gene lead to a decline in NQO1 enzyme activity. NQO1 catalyzes the two-electron reduction of quinones to hydroquinones, thereby preventing the formation of ROS. Such polymorphisms in NQO1 may increase the risk of GI cancer. The aim of this study was to evaluate the influence of the SNPs rs1800566 and rs1131341 in the NQO1 gene on the risk of GI cancer in the Netherlands. Real-time polymerase chain reaction techniques were conducted to determine the NQO1 genotypes of 1457 patients with GI cancer and 1457 age- and gender-matched controls in a case-control study. Binary logistic regression analyses showed no statistically significant difference in genotype distributions between patients and controls: odds ratios (ORs) with 95% confidence interval (CI) for rs1800566 were 1.09 (0.93-1.28) and 1.17 (0.77-1.77) for the CT and TT genotypes, respectively. ORs for rs1131341 CT and TT genotypes were 1.21 (0.90-1.63) and 0.54 (0.05-5.94), respectively. For rs1800566, a significant association between the CT genotype and proximal colon cancer was detected (OR=1.60; 95% CI=1.09-2.35). The NQO1*2 T allele of SNP rs1800566 was found associated with an increased risk for proximal colorectal cancer, whereas SNP rs1131341 was rare in our Dutch population and was not associated with GI cancer.

Evidence for NQO1 and NQO2 catalyzed reduction of ortho- and para-quinone methides

NAD(P)H

quinone oxidoreductase (NQO1) and NRH:quinone oxidoreductase 2 (NQO2) catalyze the two-electron reduction of quinones and thereby prevent generation of toxic radicals. Quinone methides (QMs) covalently react with cellular macromolecules to form DNA adducts and/or protein conjugates resulting in toxicity and carcinogenesis. Based on similar structural features of quinones and QMs, it is logical to assume that NQO1 and/or NQO2 could also catalyze the two-electron reduction of QMs. However, hitherto the reduction of QMs, as both endogenous and/or exogenous biological substrates, by either NQO1/NQO2 has never been demonstrated. Here we show for the first time that both NQO1 and NQO2 can catalyze the reduction of electrophilic ortho-/para-QMs. The involvement of the enzyme in the reduction of p-cresol quinone methide (PCQM) and o-cresol quinone methide (OCQM) was demonstrated by reappearance of NQO1/NQO2-FAD peak at 450 nm after addition of the QMs to the assay mixture. Further reduction of methides by NQO1/NQO2 was confirmed by analyzing the assay mixture by tandem mass spectrometry. Preliminary kinetic studies show that NQO2 is faster in reducing QMs than its homolog NQO1, and moreover, ortho-QMs are reduced faster than para-QMs. Enzyme-substrate docking studies showed results consistent with enzyme catalysis. Thus, NQO1/NQO2 can play a significant role in deactivation of QMs.

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphism association with digestive tract cancer: a meta-analysis

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for digestive tract cancer (DTC) in many studies; however, the results remain controversial and ambiguous. We therefore carried out a meta-analysis of published case-control studies to derive a more precise estimation of any associations. Electronic searches were conducted on links between this variant and DTC in several databases through April 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of associations in fixed or random effect models. Heterogeneity and publication bias were also assessed. A total of 21 case-control studies were identified, including 6,198 cases and 7,583 controls. Overall, there was a statistically significant association between the NQO1 C609T polymorphism and DTC risk (TT vs. CC: OR=1.224, 95%CI=1.055-1.421; TT/CT vs. CC: OR=1.195, 95%CI=1.073-1.330; TT vs. CT/CC: OR=1.183, 95%CI=1.029-1.359; T vs. C: OR=1.180, 95%CI=1.080-1.290). When stratified for tumor location, the results based on all studies showed the variant allele 609T might have a significantly increased risk of upper digest tract cancer (UGIC), but not colorectal cancer. In the subgroup analysis by ethnicity, we observed a significantly risk for DTC in Caucasians. For esophageal and gastric cancer, a significantly risk was found in both populations, and for colorectal, a weak risk was observed in Caucasians, but not Asians. This meta-analysis suggested that the NQO1 C609T polymorphism may increase the risk of DTC, especially in the upper gastric tract.

NAD(P)H:quinone oxidoreductase 1 (NQO1) P187S polymorphism and prostate cancer risk in Caucasians

NAD(P)H:quinone oxidoreductase 1 (NQO1) catalyses the reduction of quinoid compounds to hydroquinones, preventing the generation of free radicals and reactive oxygen. A “C” to “T” transversion at position 609 of NQO1, leading to a nonsynonymous amino acid change (Pro187Ser, P187S), results in an altered enzyme activity. No NQO1 protein activity was detected in NQO1⁶⁰⁹TT genotype, and low to intermediate activity was detected in NQO1⁶⁰⁹CT genotype compared with ⁶⁰⁹CC genotype. Thus, this polymorphism may result in altered cancer predisposition. For prostate cancer, only sparse data are available. We therefore analyzed the distribution of the NQO1 P187S SNP (single nucleotide polymorphism) in prostate cancer patients and a healthy control group. Allelic variants were determined using RFLP analysis. Overall, 232 patients without any malignancy and 119 consecutive prostate cancer patients were investigated. The genotype distribution in our cohorts followed the Hardy–Weinberg equilibrium in cases and controls. The distribution of the NQO1 codon 187 SNP did not differ significantly between prostate cancer patients and the control group (p = 0.242). There was also no association between the allelic variants and stage or Gleason score of the tumors. The NQO1 P187S SNP was not significantly associated with an increased prostate cancer risk in our cohorts. The SNP has also no influence on histopathological characteristics of the tumors. A combined analysis of all available data from published European studies also showed no significant differences in the genotype distribution between controls and prostate cancer patients. Our data suggest a minor role of the NQO1 nucleotide 609 polymorphism in prostate carcinogenesis.