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

Polymorphisms in NQO1 and MPO genes and risk for bladder cancer in Tunisian population

BACKGROUND

NAD (P) H: quinone oxidoreductase (1) (NQO1-HGNC: 2874) and myeloperoxidase (MPO-HGNC: 7218) are two enzymes involved in phase II of the xenobiotic metabolism pathway.

METHODS

In this study, a case-control analysis was conducted to investigate the relationship between genetic variations in the NQO1 (C609T, rs1800566; IVS1-27 C >G, rs689452) and MPO (G463A, rs2333227) genes and the risk for bladder cancer among Tunisian population.

RESULTS

We have found that the MPO 463GA genotype was associated with a decreased risk of developing bladder cancer (p = 0.049; OR = 0.696; 95% CI 0.484-0.999). In contrast, we have found that the NQO1 609CT genotype could increase the risk of bladder cancer patients (p = 0.0039; OR = 1.454; 95% CI = 1.017-2.078). Moreover, patients with "NQO1 609 CT/IVS1-27 CG" genotype show a 2.180-fold increasing risk for developing bladder cancer in comparison to the control group with wild genotype. This OR is estimated at 5.6-fold in smokers patients with "NQO1 609 CT/IVS1-27 CG" genotype. Lastly, study findings suggest that the NQO1 IVS-27 *CG genotype (rs689452) is associated with a risk of progression to muscle invasive bladder cancer.

CONCLUSION

Our study suggests that environmental risk factors in association to NQO1 genotypes (NQO1 609 CT/IVS1-27 CG) play an important role in the development of bladder cancer in Tunisian population.

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.

Down-regulating NQO1 promotes cellular proliferation in K562 cells via elevating DNA synthesis

BACKGROUND

NQO1 protein acts as a cellular protective system, on account of its role as a quinone reductase and redox regulator. Nonetheless, new NQO1 roles are emerging-including its regulation of the cellular proliferation of many tumor cells-and this enzyme has been found to relate to the incidence of various diseases, including chronic myeloid leukemia. However, the mechanisms through which NQO1 influences leukemia progression remain unclear.

MARTIAL AND METHODS

The current study looks to name NQO1 as a novel molecular target that modulates DNA synthesis and chronic myeloid leukemia growth.

RESULTS AND CONCLUSION

Our results indicate that the frequency of the T allele of NQO1 polymorphism in chronic myeloid leukemia patients is higher than that among healthy East Asian individuals (0.492 vs. 0.419) and much higher than the average level of the general population (0.492 vs. 0.289) (1000 Genomes). Functionally, NQO1 knockdown increases the protein expression of the TOP2A and MCM complex, and consequently promotes DNA synthesis and K562 cell growth. NQO1 knockdown also promotes tumorigenesis in a xenograft model. NQO1 overexpression, on the other hand, was found to have the opposite effects.

SIGNIFICANCE

Our results show that NQO1 downregulation promotes K562 cellular proliferation via the elevation of DNA synthesis.

IDH1 R132H mutation regulates glioma chemosensitivity through Nrf2 pathway

Purpose

Numerous studies have reported that glioma patients with isocitrate dehydrogenase 1(IDH1) R132H mutation are sensitive to temozolomide treatment. However, the mechanism of IDH1 mutations on the chemosensitivity of glioma remains unclear. In this study, we investigated the role and the potential mechanism of Nrf2 in IDH1 R132H-mediated drug resistance.

Methods

Wild type IDH1 (R132H-WT) and mutant IDH1 (R132H) plasmids were constructed. Stable U87 cells and U251 cells overexpressing IDH1 were generated. Phenotypic differences between IDH1-WT and IDH1 R132H overexpressing cells were evaluated using MTT, cell colony formation assay, scratch test assay and flow cytometry. Expression of IDH1 and its associated targets, nuclear factor-erythroid 2-related factor 2 (Nrf2), NAD(P)H quinine oxidoreductase 1 (NQO1), multidrug resistant protein 1 (MRP1) and p53 were analyzed.

Results

The IDH1 R132H overexpressing cells were more sensitive to temozolomide than WT and the control, and Nrf2 was significantly decreased in IDH1 R132H overexpressing cells. We found that knocking down Nrf2 could decrease resistance to temozolomide. The nuclear translocation of Nrf2 in IDH1 R132H overexpressing cells was lower than the WT and the control groups after temozolomide treatment. When compared with WT cells, NQO1 expression was reduced in IDH1 R132H cells, especially after temozolomide treatment. P53 was involved in the resistance mechanism of temozolomide mediated by Nrf2 and NQO1.

Conclusions

Nrf2 played an important role in IDH1 R132H-mediated drug resistance. The present study provides new insight for glioma chemotherapy with temozolomide.

Pharmacokinetic and safety evaluation of MB12066, an NQO1 substrate

Objective

This study evaluated the pharmacokinetics (PKs) and safety of a newly developed β-lapachone (MB12066) tablet, a natural NAD(P)H:quinone oxidoreductase 1 (NQO1) substrate, in healthy male volunteers.

Methods

In a randomized, double-blind, multiple-dose, two-treatment study, 100 mg MB12066 or placebo was given twice daily for 8 days to groups of eight or three fasted healthy male subjects, respectively, followed by serial blood sampling. Plasma concentrations for β-lapachone were determined using liquid chromatography–tandem mass spectrometry. PK parameters were obtained with non-compartmental analysis. Tolerability was assessed based on physical examinations, vital signs, clinical laboratory tests, and electrocardiograms.

Results

Following a single 100 mg MB12066 oral dose, maximum plasma concentration (C_max) of β-lapachone was 3.56±1.55 ng/mL, and the median (range) time to reach C_max was 3 h (2–5 h). After the 8 days of 100 mg twice daily repeated dosing was completed, mean terminal half-life was determined to be 18.16±3.14 h, and the mean area under the plasma concentration vs time curve at steady state was 50.44±29.68 ng·h/mL. Accumulation index was 2.72±0.37. No serious adverse events (AEs) were reported, and all reported intensities of AEs were mild.

Conclusion

The results demonstrated that MB12066 was safe and well tolerated in healthy volunteers and that there were no serious AEs. Accumulation in plasma with twice-daily administration was associated with a 2.72 accumulation ratio.

A functional pseudogene, NMRAL2P, is regulated by Nrf2 and serves as a coactivator of NQO1 in sulforaphane-treated colon cancer cells

SCOPE

The anticancer agent sulforaphane (SFN) acts via multiple mechanisms to modulate gene expression, including the induction of nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-dependent signaling and the inhibition of histone deacetylase activity. Transcriptomics studies were performed in SFN-treated human colon cancer cells and in nontransformed colonic epithelial cells in order to pursue new mechanistic leads.

METHODS AND RESULTS

RNA-sequencing corroborated the expected changes in cancer-related pathways after SFN treatment. In addition to NAD(P)H quinone dehydrogenase 1 (NQO1) and other well-known Nrf2-dependent targets, SFN strongly induced the expression of Loc344887. This noncoding RNA was confirmed as a novel functional pseudogene for NmrA-like redox sensor 1, and was given the name NmrA-like redox sensor 2 pseudogene (NMRAL2P). Chromatin immunoprecipitation experiments corroborated the presence of Nrf2 interactions on the NMRAL2P genomic region, and interestingly, NMRAL2P also served as a coregulator of NQO1 in human colon cancer cells. Silencing of NMRAL2P via CRISPR/Cas9 genome-editing protected against SFN-mediated inhibition of cancer cell growth, colony formation, and migration.

CONCLUSION

NMRAL2P is the first functional pseudogene to be identified both as a direct transcriptional target of Nrf2, and as a downstream regulator of Nrf2-dependent NQO1 induction. Further studies are warranted on NMRAL2P-Nrf2 crosstalk and the associated mechanisms of gene regulation.

Correlation between NAD(P)H: quinone oxidoreductase 1 C609T polymorphism and increased risk of esophageal cancer: evidence from a meta-analysis

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for esophageal cancer (EC) in many studies. However, the results remain controversial and ambiguous. We performed a meta-analysis, which included 13 independent studies with a total of 2357 subjects, to examine the association between NQO1 C609T polymorphism and EC. The association was assessed by five different gene models. The overall analysis suggested that the variant allele and genotypes were significantly related to increased risk of EC (odds ratio [OR] T versus C = 1.15, 95% confidence interval [CI] 0.95-1.40, probability of rejection [POR] = 0.014; OR TT versus CC = 1.32, 95% CI 1.01-1.73, POR = 0.045; OR TC versus CC = 1.32, 95% CI 0.98-1.21, POR = 0.128; OR TT + TC versus CC = 1.10, 95% CI 1.00-1.20, POR = 0.05; OR TT versus CC + TC = 1.26, 95% CI 0.95-1.57, POR = 0.103). Sensitivity analysis confirmed the reliability of these findings. Our study shows that individuals carrying the NQO1 C609T variant allele and genotypes are more susceptible to EC.

Analysis of possible genetic risk factors contributing to development of childhood acute lymphoblastic leukaemia in the Latvian population

INTRODUCTION

Childhood acute lymphoblastic leukaemia (ALL) is a complex disease caused by a combination of genetic susceptibility and environmental exposure. Previous genome-wide association studies have reported several single nucleotide polymorphisms (SNPs) associated with the incidence of ALL. Several variations in genes encoding enzymes involved in carcinogenesis are suggested as being associated with an increased risk of ALL development.

MATERIAL AND METHODS

We enrolled 77 paediatric ALL patients and 122 healthy controls, and in addition parental DNA was also available for 45 probands. SNPs rs10821936 (ARID5B), rs4132601 (IKZF1), rs2239633 (CEBPE), rs3731217 (CDKN2A) and rs1800566 (NQO1) and the presence of GSTT1 and GSTM1 null variants were detected. For statistical analysis the hybrid method of two designs 'Haplin' was used as well as linkage disequilibrium for family-based association studies.

RESULTS

We identified the SNP rs10821936 in the ARID5B gene as being statistically significantly associated with childhood ALL, especially if the C allele is in a homozygous state, relative risk (RR) 4.65, 95% CI: 2.03-10.6, p = 0.0006. Statistically significant differences were not found in other SNPs. We found risk combinations including all five variations, the strongest association being found in a combination where all five genetic variants are in a homozygous state, CCTTTTTTCC, p = 0.032.

CONCLUSIONS

The identified SNP rs10821936 could serve as a potential risk marker for childhood ALL development. Further studies in an independent population are needed for verification.

Novel non invasive diagnostic strategies in bladder cancer

Bladder cancer is one of the most commonly diagnosed malignancies worldwide, derived from the urothelium of the urinary bladder and defined by long asymptomatic and atypical clinical picture. Its complex etiopathogenesis is dependent on numerous risk factors that can be divided into three distinct categories: genetic and molecular abnormalities, chemical or environmental exposure and previous genitourinary disorders and family history of different malignancies. Various genetic polymorphisms and microRNA might represent useful diagnostic or prognostic biomarkers. Genetic and molecular abnormalities - risk factors are represented by miRNA or genetic polymorphisms proved to be part of bladder carcinogenesis such as: genetic mutations of oncogenes TP53, Ras, Rb1 or p21 oncoproteins, cyclin D or genetic polymorhisms of XPD,ERCC1, CYP1B1, NQO1C609T, MDM2SNP309, CHEK2, ERCC6, NRF2, NQO1Pro187Ser polymorphism and microRNA (miR-143, −145, −222, −210, −10b, 576-3p). The aim of our article is to highlight the most recent acquisitions via molecular biomarkers (miRNAs and genetic polymorphisms) involved in bladder cancer in order to provide early diagnosis, precise therapy according to the molecular profile of bladder tumors, as well as to improve clinical outcome, survival rates and life quality of oncological patients. These molecular biomarkers play a key role in bladder carcinogenesis, clinical evolution, prognosis and therapeutic response and explain the molecular mechanisms involved in bladder carcinogenesis; they can also be selected as therapeutic targets in developing novel therapeutic strategies in bladder malignancies. Moreover, the purpose in defining these molecular non invasive biomarkers is also to develop non invasive screening programs in bladder malignancies with the result of decreasing bladder cancer incidence in risk population.

Implications of NQO1 in cancer therapy

NAD(P)H

quinone oxidoreductase (NQO1), an obligatory two-electron reductase, is a ubiquitous cytosolic enzyme that catalyzes the reduction of quinone substrates. The NQO1- mediated two-electron reduction of quinones can be either chemoprotection/detoxification or a chemotherapeutic response, depending on the target quinones. When toxic quinones are reduced by NQO1, they are conjugated with glutathione or glucuronic acid and excreted from the cells. Based on this protective effect of NQO1, the use of dietary compounds to induce the expression of NQO1 has emerged as a promising strategy for cancer prevention. On the other hand, NQO1-mediated two-electron reduction converts certain quinone compounds (such as mitomycin C, E09, RH1 and -lapachone) to cytotoxic agents, leading to cell death. It has been known that NQO1 is expressed at high levels in numerous human cancers, including breast, colon, cervix, lung, and pancreas, as compared with normal tissues. This implies that tumors can be preferentially damaged relative to normal tissue by cytotoxic quinone drugs. Importantly, NQO1 has been shown to stabilize many proteins, including p53 and p33ING1b, by inhibiting their proteasomal degradation. This review will summarize the biological roles of NQO1 in cancer, with emphasis on recent findings and the potential of NQO1 as a therapeutic target for the cancer therapy.

NQO1 Stabilizes p53 in Response to Oncogene-Induced Senescence

Cellular senescence is a state of permanent cellular arrest that provides an initial barrier to cell transformation and tumorigenesis. In this study, we report that expression of NAD(P)H:quinone oxidoreductase 1 (NQO1), a cytoplasmic 2-electron reductase, is induced during oncogene-induced senescence (OIS). Depletion of NQO1 resulted in the delayed onset of senescence. In contrast, ectopic expression of NQO1 enhanced the senescence phenotype. Analysis of the mechanism underlying the up-regulation of NQO1 expression during senescence identified that NQO1 promotes p53 accumulation in an MDM2 and ubiquitin independent manner, which reinforces the cellular senescence phenotype. Specifically, we demonstrated that NRF2/KEAP1 signaling regulates NQO1 expression during OIS. More importantly, we confirmed that depletion of NQO1 facilitates cell transformation and tumorigenesis, which indicates that NQO1 takes part in the senescence barrier and has anti-oncogenic properties in cell transformation.

The importance of G2677T/A and C3435T polymorphisms of the MDR1 gene in the aetiology of colorectal cancer

Introduction

Colorectal cancer (CRC) is the most common cancer among patients, and its aetiology is still not precisely known. It is believed that 15–30% of colorectal cancers are genetically determined. P-glycoprotein (P-gp) encoded by the MDR1 gene in normal conditions plays an important role in the action of colon epithelial cells. However, the MDR1 polymorphism influences the P-gp expression and can weaken its effect against xenobiotics (procarcinogens) and increase the frequency of CRC.

Aim

To evaluate the correlation between the MDR1 C3435T and G2677T/A polymorphisms and the risk of colorectal cancer.

Material and methods

The study group with colorectal cancer included 47 women and 60 men while the control group consisted of 110 healthy patients. The diagnosis in patients suffering from CRC was confirmed by histopathological report. Genetic analysis was performed using PCR-RFLP method.

Results

We showed only a correlation between the frequency of CT and TT genotypes of C3435T polymorphism and the risk of colorectal cancer in younger age. There was no correlation between the C3435T and G2677T/A polymorphisms of the MDR1 gene and other clinical parameters.

Conclusions

Our findings suggest that T allele carriers of C3435T polymorphism have an increased risk of CRC. However, further studies are needed on a much larger number of patients and genes associated with metabolism and transport of xenobiotics including procarcinogens.