Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.6.5.2 (NQO1)
6,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The molecular pathogenesis of therapy-related acute myeloid leukaemia/myelodysplastic syndrome (t-AML/MDS) remains uncertain. However, clonal haemopoiesis may develop following stem cell transplantation and precede the development of t-AML/MDS. Moreover, accelerated telomere shortening may be induced by replicative stress or oxidative damage, leading to genomic instability, and inactivating polymorphisms of the gene encoding NADPH-quinone oxidoreductase (NQO1) are more frequently observed in patients with t-AML. We studied clonal haemopoiesis, telomere length and NQO1 status in 146 patients receiving conventional chemotherapy for non-myeloid malignancies. Clonal haemopoiesis was demonstrated in eight of 98 (8%) patients. Telomere length was reduced in patients following chemotherapy (n = 52) compared with controls (n = 42) (P < 0.001), particularly in those with clonal haemopoiesis (P < 0.002). Whilst there was a trend towards telomere shortening in control subjects polymorphic for NQO1-187Ser (n = 12), chemotherapy-exposed patients polymorphic for the NQO1-187Ser allele (n = 29) had significantly shorter telomeres (P < 0.001). Furthermore, chemotherapy-treated patients with the NQO1-187Ser, polymorphism were more likely to develop clonal haemopoiesis than patients with wild type NQO1 (odds ratio = 7; 1.16-42.6). We conclude that a switch to clonal haemopoiesis may occur after conventional chemotherapy and lead to accelerated telomere shortening. Patients with the NQO1-187Ser polymorphism have an increased risk of developing both clonal haemopoiesis and telomere shortening, which may partly explain the predisposition to t-AML in NQO1-187Ser null individuals.
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PMID:Clonal haemopoiesis may occur after conventional chemotherapy and is associated with accelerated telomere shortening and defects in the NQO1 pathway; possible mechanisms leading to an increased risk of t-AML/MDS. 1519 33

The effects of a number of cytotoxic drugs are influenced by cellular reduction/oxidation (redox) state. In the present study, we attempt to explore if dicoumarol, an inhibitor of NADPH: quinone oxidoreductase (NQO1), alters the cellular redox state and how this alteration affects the redox-related apoptosis. Flow cytometry was used to assess the reactive oxygen species (ROS) level and apoptotic rates of HeLa cells treated with arsenic trioxide (As2O3) alone or in combination with natural anthraquinone emodin and dicoumarol or plus N-acetyl-cysteine. Western blot, immunofluorescence, electrophoretic mobility shift assay and luciferase assay were used to detect Nuclear Factor kappa B (NF-kappaB) activation. The results showed that dicoumarol synergized with emodin to sensitize HeLa cells to As2O3-induced apoptosis through raising the ROS level. More notably, this enhanced susceptibility was associated with a ROS-mediated inhibition of NF-kappaB activation in which the combinative treatment with dicoumarol prevented NF-kappaB from binding to target DNA. It was suggested that dicoumarol in combination with anthraquinones might be a novel strategy to expand the chemotherapeutic spectrum of As2O3 by means of interfering the cellular redox state.
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PMID:Dicoumarol alters cellular redox state and inhibits nuclear factor kappa B to enhance arsenic trioxide-induced apoptosis. 1520 9

Excess production of H2O2 has been implicated in oncogenesis. The object of the present study was twofold: first, to determine the influence of chronic estradiol (E2) on the activities of selected hepatic antioxidant enzymes in female ACI rats, a strain that is highly sensitive to the induction of estrogen dependent mammary tumors; secondly, to evaluate the actions of dietary clofibrate, a peroxisome proliferator, on activities of these enzymes in control and E2-treated ACI rats. Enzymes selected for study were: NAD(P)H quinone oxidoreductase (NQO1), glutathione S-transferase (GST) and glutathione peroxidase (GPx). Cytosolic catalase (CAT) was also measured as an index of peroxisome proferation in control and E2- treated animals. E2 was administered chronically over 6 and 12 week periods from cholesterol pellet implants containing either 1 or 3 mg E2. Animals were fed AIN-76A diets with or without 0.4% clofibrate over the experimental period. NQO1 and GST but not GPx were induced to varying degrees (NQO1 about 300%, and GST about 45-97%) by chronic E2-treatment. E2-induced increases in these activities were completely prevented in rats exposed to dietary clofibrate. Dietary clofibrate also caused slight but significant reductions in baseline activities of NQO1, GST and GPx in control animals. Serum E2 levels, increased approximately 540% in a dose-dependent manner, and were not altered by dietary clofibrate. It is concluded that chronic E2 treatment markedly induces several important hepatic antioxidant enzymes in female ACI rats, and induction of these activities by E2 is inhibited completely by dietary clofibrate. Both of these actions have the potential to markedly influence the profile of E2 metabolites exported from the liver to E2 sensitive extrahepatic tissues and influence the initiation and progression of hormone-dependent tumors.
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PMID:Dietary clofibrate inhibits induction of hepatic antioxidant enzymes by chronic estradiol in female ACI rats. 1521 7

On June 9, 2003, we started free genetic tests of eight polymorphisms for health checkup examinees who attended a basic course at Nagoya University Hospital. They were informed of their genotypes within four weeks after blood donation for research purposes. The genotypes were those of alcohol dehydrogenase 2 (ADH2) Arg47His, aldehyde dehydrogenase 2 (ALDH2) Glu487Lys, NAD(P)H: quinone oxidoreductase (NQO1) C609T, glutathione S transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), interleukin-1B (IL-1B) C-31T, and tumor necrosis factor A (TNF-A) T-1031C, angiotensin-converting enzyme (ACE) Ins/Del. In the first three months, 227 (89.4%) out of 254 examinees participated in the free tests, having been informed of the research aims, after which they consented to our use of research data. To date, there have been no complaints from the participants, indicating that the announcement of polymorphism genotypes may be accepted differently from that of hereditary disease genotypes.
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PMID:Genotype announcement in a genetic polymorphism study for health checkup examinees at Nagoya University Hospital. 1527 67

Genetic polymorphisms have the potential to predict disease susceptibility. This may be especially useful among individuals with a high-risk lifestyle, so that the genotyping could be adopted for disease prevention through modifications toward a lower-risk lifestyle. We started a program of free genotype announcements in a polymorphism study among health checkup examinees at the Nagoya University Hospital on June 9, 2003. Since such announcements remain controversial for fear of unexpected harmful effects and counseling system, the accumulated evidence on the association between disease risk and genotypes announcements in our study was reviewed in this article. The genotypes used were those of alcohol dehydrogenase 2 (ADH2) Arg47His, aldelhyde dehydlrogenase 2 (ALDH2) Glu487Lys, NAD(P)H: quinone oxidoreductase (NQO1) C609T, glutathlione S transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), interleukin-1B (IL-1B) C-31T, and tumor necrosis factor A (TNF-A) T-1031C, angiotensin converting enzyme (ACE) Ins/Del. Since showed a potential for widespread use in health checkups, the information on the above polymorphisms seems worth documenting. Although there have been no complaints from the participants to date, careful treatments are requested.
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PMID:Associations between disease risk and eight polymorphisms adopted for genotype announcements at Nagoya University Hospital. 1527 68

We aimed at determining whether any association exists between genetic polymorphisms in epoxide hydrolase (EPHX1), NADPH-quinone oxidoreductase (NQO1), glutathione S-transferases (GSTM1/P1/T1) and individual susceptibility to breast cancer. Polymerase chain reaction-restriction fragment length polymorphism-based genotyping assays were used to determine the frequency of polymorphisms in EPHX1 (exons 3 and 4), NQO1 (exon 6), GSTM1 (deletion), GSTP1 (exon 5), and GSTT1 (deletion) in a case-control study comprised of 238 patients with breast cancer and 313 healthy individuals. The distribution of genotypes in exon 6 of NQO1 was significantly different between the control group and breast cancer cases. Age-adjusted odds ratio (OR) for variant genotype NQO1*2/*2 was 3.68 (confidence interval (CI) = 1.41-9.62, P = 0.008). Association of GSTP1*2/*2 genotype as well as that of low EPHX1 activity deduced by combinations of genotypes in exons 3 and 4 with breast cancer was suggestive, but nonsignificant. Individuals simultaneously lacking GSTM1 and carrying at least one GSTP1 variant allele were at significantly higher risk of breast cancer (OR = 2.03, CI = 1.18-3.50, P = 0.010). Combinations of either GSTM1null or GSTP1*2 with low activity of EPHX1 presented significant risk of breast cancer (OR = 1.88, CI = 1.00-3.52, P = 0.049 and OR = 2.40, CI = 1.15-5.00, P = 0.019, respectively) as well. In conclusion, the results suggest that genetic polymorphisms in biotransformation enzymes may play a significant role in the development of breast cancer.
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PMID:Breast cancer: role of polymorphisms in biotransformation enzymes. 1528 Sep 3

NAD(P)H:Quinone oxidoreductase-1 (NQO1) has been implicated in the bioreductive activation of the clinically active anticancer drug Mitomycin C (MMC) and a polymorphic variant of NQO1 which lacks functional enzyme activity (NQO1*2) has been linked with poor survival in patients treated with MMC. The relationship between NQO1 activity and cellular response to MMC is however controversial and the aim of this study was to determine whether the response of bladder cancer patients to MMC can be forecast on the basis of NQO1*2 genotype status. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue from 148 patients with low to intermediate grade (G1/G2) superficial (Ta/T1) bladder cancers and NQO1*2 genotype status determined by PCR-RFLP. NQO1*2 genotype status was retrospectively compared with clinical response to intravesical administered MMC with the primary end-point being time to first recurrence. NQO1 phenotype was determined by immunohistochemistry. Of the 148 patients genotyped, 85 (57.4%) were NQO1*1 (wild-type), 59 (39.8%) were NQO1*1/*2 (heterozygotes) and 4 (2.7%) were NQO1*2/*2. No NQO1 protein expression was detected in NQO1*2/*2 tumours. A broad spectrum of NQO1 protein expression existed in tumours genotyped as NQO1*1 and NQO1*1/*2 although tumours with NQO1*1 typically expressed higher NQO1 protein. A poor correlation existed between NQO1*2 genotype status and clinical response to MMC. The results of this retrospective study suggest that tailoring MMC therapy to individual patients with superficial bladder cancer on the basis of NQO1 genotype status is unlikely to be of clinical benefit.
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PMID:NAD(P)H:Quinone oxidoreductase-1 C609T polymorphism analysis in human superficial bladder cancers: relationship of genotype status to NQO1 phenotype and clinical response to Mitomycin C. 1537 41

This paper reviews the literature on the influence of metabolic and DNA repair polymorphisms of biological indicators of genotoxic risk commonly used in biomonitoring occupational exposure to carcinogens. Genetic polymorphisms which influence biomarkers (urinary metabolites, protein and DNA adducts), include P450 cytochromes (CYPs) and glutathione S-transferases (GSTs) in exposure to polycyclic aromatic hydrocarbons (PAHs), and acetyltransferases (NATs) in exposure to aromatic amines (AAs). As regards exposure to benzene, also relevant is the influence of epoxydohydrolase (EPHX) and NAD(P)H quinone oxidoreductase (NQO1) on the urinary excretion of t,t-muconic and phenylmercapturic acids. With respect to occupational exposure to styrene, EPHX significantly influences the levels of Chromosome Aberrations (CAs), strongly predictive genotoxic biomarkers of cancer risk. Some recent studies examine the role of polymorphisms linked to DNA repair genes in the modulation of genotoxic risk associated with PAH exposure, both for life-style (dietary and smoking behaviour) and for occupational reasons. In addition, molecular epidemiology studies (case/control studies) of lung cancer in smokers published since 2000 may also be viewed as representing models of effects due to exposure to carcinogenic mixtures, some of which are present in the working environment (e.g., BaP, benzene, AAs). Almost all studies show the clearcut influence (i.e., increased lung cancer risk with OR > or = 2) of genetic polymorphisms linked to PAH metabolism (in particular, CYPIA1, GSTM1 and P1). Among the risk factors are the different mutagen sensitivity towards, for instance, bleomycin and BaP (tested in vitro), the reduced repair capacity to DNA damage induced by BaP, and increases in some biomarkers of early biological effect (DNA adducts and stable CAs). Other risk factors, such as heredity (siblings of cancer patients have a risk factor > or = 3 with respect to the general population), ethnicity (Chileans > Caucasians; Japanese > Americans) and gender (women > men), have still not been clearly characterized and these are also reported in this paper. It is clear from the above that genetic differences underlie individual susceptibility to lung cancer, whether caused by exposure to tobacco smoke or to occupational carcinogens like PAHs. Some of these indicators of exposure/individual susceptibility can be evaluated in groups at high risk of occupational lung cancer, such as coke-oven and aluminium workers and those exposed to coal tar fumes and soot, etc., with the aim of identifying subjects who are susceptible due to the high concentrations of carcinogens found in their working environment.
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PMID:[Individual susceptibility to occupational carcinogens: the evidence from biomonitoring and molecular epidemiology studies]. 1558 38

Reactive oxygen species derived from dopamine metabolism can induce oxidative stress and thus may contribute to Parkinson's disease (PD) pathogenesis. The quinone oxidoreductases, nicotinamide adenine dinucleotide (phosphate) (NAD[P]H): quinone oxidoreductase 1 (NQO1) and dihydronicotinamide riboside (NRH): quinone oxidoreductase 2 (NQO2) detoxify quinones and quinonoid compounds. We investigated associations of genetic polymorphisms of NQO1 (C609T) and NQO2 (I/D, 29 base pairs) with PD in a population-based case-control study of 190 idiopathic PD cases and 305 unrelated controls matched on age and sex. No associations were detected for either gene variant or for any allele combinations.
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PMID:No associations between Parkinson's disease and polymorphisms of the quinone oxidoreductase (NQO1, NQO2) genes. 1569 56

A number of alkynols have been prepared by Sonogashira coupling of propargyl alcohol to aromatic halides. Chelation-controlled addition of organometallic nucleophiles to these alkynols was then effected followed by the addition of the sulfur electrophiles, sulfur dioxide or thionyl chloride. This methodology was used to prepare a number of oxathiolene oxides, which have been screened as NQO1 (quinone oxidoreductase) inducers.
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PMID:Oxathiolene oxide synthesis via chelation-controlled addition of organometallic reagents to alkynols followed by addition of sulfur electrophiles and evaluation of oxathiolene oxides as anticarcinogenic enzyme inducers. 1572 74


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