Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.5.2 (NQO1)
 6,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In recent years, considerable emphasis has been focused on identifying new chemopreventive agents, which could be useful for the human population. Piperine is a pure, pungent alkaloid constituent of black and long peppers (piper nigrum and piper longum), which is a most common spice used throughout the world. In the present study, we examined the protective role of piperine during experimental lung carcinogenesis with reference to its effect on DNA damage and detoxification enzyme system. The activities of detoxifying enzymes such as glutathione transferase (GST), quinone reductase (QR) and UDP-glucuronosyl transferase (UDP-GT) were found to be decreased while the hydrogen peroxide level was increased in the lung cancer bearing animals. Supplementation of piperine (50 mg/kg bwt) enhanced the detoxification enzymes and reduced DNA damage as determined by single cell electrophoresis. Furthermore, the DNA-Protein cross links which was found to be high in lung cancer bearing animals was also modulated upon supplementation with piperine. Our present results explain the understanding of unique association between anti-peroxidative effect of piperine and ultimately the capability of piperine to prevent cancer.
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PMID:Oral supplementation of piperine leads to altered phase II enzymes and reduced DNA damage and DNA-protein cross links in Benzo(a)pyrene induced experimental lung carcinogenesis. 1572 47

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.
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PMID:An association between a NQO1 genetic polymorphism and risk of lung cancer. 1578 Dec 12

The genetic susceptibility hypothesis has been used to explain why only a minority of smokers develop lung cancer. Only few studies have studied the role of polymorphisms in phase-I and II metabolizing genes, among young lung cancer patients. We have pooled the individual data of three studies from Denmark and Norway, including 320 patients diagnosed with non-small cell lung cancer at age 59 or below, and 618 age and gender matched controls. A questionnaire was used to determine relevant demographic and lifestyle characteristics, and polymorphisms in following genotypes were determined GSTM1, GSTM3, GSTP1, GSTT1, GPX1, MPO, NQO1 and NAT2. Based on the literature, the alleles of the genotypes were categorised as high- or low-risk alleles. No individual effect of the genotypes was found on the risk of lung cancer. Given a smoking exposure, the presence of high-risk alleles (or phenotypes) was generally found to increase the risk of lung cancer, although the effect modification did not reach statistical significance. A pattern of stronger protective effect was observed in carriers of more than one allele associated with lower risk of lung cancer, and a higher risk of lung cancer in carriers of one or more alleles associated with higher risk of lung cancer, but the results did not reach statistical significance. The effect modification was generally strongest at lower levels of smoking.
Lung Cancer 2005 May
PMID:Polymorphisms in genes involved in xenobiotic metabolism and lung cancer risk under the age of 60 years. A pooled study of lung cancer patients in Denmark and Norway. 1582 18

The cytochrome P450 (CYP) superfamily of enzymes catalyse one of the first steps in the metabolism of carcinogens such as polycyclic aromatic hydrocarbons, nitroaromatics and arylamines. Polymorphisms within the CYP1A1 gene have been shown to be associated with lung cancer risk, predominantly among Asian populations. Despite functional evidence of a possible role of CYP1B1 in lung cancer susceptibility, only a few studies have evaluated polymorphisms in this gene in relation to lung cancer susceptibility. This population-based study evaluates polymorphisms in both of these CYP genes within never smokers, most of whom had environmental tobacco smoke (ETS) exposure. Cases (n = 160) were identified through the metropolitan Detroit Surveillance, Epidemiology and End Results program, and age, sex and race-matched population-based controls (n = 181) were identified using random digit dialing. Neither CYP1A1 MspI nor CYP1A1 Ile(462)Val was associated with lung cancer susceptibility among Caucasians or African-Americans. Among Caucasians, however, CYP1B1 Leu(432)Val was significantly associated with lung cancer susceptibility odds ratio (OR) for at least one valine allele = 2.87 [95% confidence interval (CI) 1.63-5.07]. Combinations of this Phase I enzyme polymorphism along with selected Phase II enzyme polymorphisms (GSTM1 null, GSTP1 Ile(105)Val and NQO1 C(609)T) were evaluated. The combination of CYP1B1 Leu(432)Val and NQO1 C(609)T appeared to be associated with the highest risk of lung cancer (OR = 4.14, 95% CI 1.60-10.74), although no combinations differed significantly from the risk associated with CYP1B1 Leu(432)Val alone. When individuals were stratified by household ETS exposure (yes/no), CYP1B1 Leu(432)Val alone and in combination with Phase II enzyme polymorphisms was more strongly associated with increased lung cancer susceptibility among those with at least some household ETS exposure. Additional studies will be required to further validate these findings among never smokers and to evaluate the effects of this polymorphism among smoking populations as well.
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PMID:CYP1A1 and CYP1B1 polymorphisms and risk of lung cancer among never smokers: a population-based study. 1605 42

An association between functional polymorphisms of genes resulting in decreased detoxification of carcinogens or DNA repair and aberrant promoter methylation is an attractive hypothesis in lung carcinogenesis. The genotypes at polymorphic sites of the glutathione S-transferase (GST) M1 (null/wildtype) and P1 (nucleotide 2627 A/G), myeloperoxidase (MPO) (nucleotide -463 G/A), X-ray repair cross-complementing group 1 (XRCC1) (nucleotides 26304 C/T; 28152 G/A), and NADPH quinine oxidoreductase (NQO1) (nucleotide 609 C/T) genes in 75 Chinese patients with non-small cell lung cancer (NSCLC) were characterized with polymerase chain reaction-restriction fragment length polymorphism. Results were correlated with aberrant methylation of the CDKN2A (alias p16(INK4A)), retinoic acid receptor beta (RARB), methylguanine-DNA methyltransferase (MGMT), and death-associated-protein (DAP) kinase genes in the tumors. In comparison with an age-matched control, none of the polymorphisms were associated with increased lung cancer risks. In male patients, however, the MPO -463 GG homozygous state was associated with CDKN2A (alias p16(INK4A)) methylation (odds ratio OR=3.63, 95% confidence interval CI=1.26-10.51), and the XRCC1 26304 T allele in the heterozygous/homozygous state was associated with methylation of CDKN2A (OR=6.13, 95% CI=1.55-24.16) and RARB (OR=7.67, 95% CI=1.62-36.18). In female patients, the GSTP1 G allele in the heterozygous/homozygous state was associated with RARB methylation (OR=18.0, 95% CI=0.76-427.29). These results showed that functional deficiencies in metabolic pathways that protect cells from carcinogen induced DNA damage might be linked to aberrant promoter methylation of the CDKN2A and RARB genes during lung carcinogenesis.
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PMID:Polymorphisms of the GSTM1, GSTP1, MPO, XRCC1, and NQO1 genes in Chinese patients with non-small cell lung cancers: relationship with aberrant promoter methylation of the CDKN2A and RARB genes. 1615 95

The aim of this study is to summarize the available molecular epidemiologic studies of lung cancer and metabolic genes, such as NAD(P)H quinone reductase 1 (NQO1) and myeloperoxidase (MPO). NQO1 plays a dual role in the detoxification and activation of procarcinogens whereas MPO has Phase I activity by converting lipophilic carcinogens into hydrophilic forms. Variant genotypes of both NQO1 Pro187 Ser and MPO G-463A polymorphisms may be related to low enzyme activity. The Pro/Ser and Ser/Ser genotypes combined of NQO1 was significantly associated with decreased risk of lung cancer in Japanese [random effects odds ratio (OR) = 0.70, 95% confidence interval (CI) = 0.56-0.88] among whom the variant allele is common. The variant genotype of MPO was associated with decreased risk of lung cancer among Caucasians (random effects OR = 0.70, 95% CI = 0.47-1.04). Gene-environment interactions in both polymorphisms may be hampered by inaccurate categorization of tobacco exposure. Evidence on gene-gene interactions is extremely limited. As lung cancer is a multifactorial disease, an improved understanding of such interactions may help identify individuals at risk for developing lung cancer. Such a study should include larger sample size and other polymorphisms in the metabolism of tobacco-derived carcinogens and address interactions with smoking status. The effects of polymorphisms are best represented by their haplotypes. In future studies on lung cancer, the development of haplotype-based approaches will facilitate the evaluation of haplotypic effects, either for selected polymorphisms physically close to each other or for multiple genes within the same drug-metabolism pathway.
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PMID:NQO1, MPO, and the risk of lung cancer: a HuGE review. 1617 Feb 38

Arsenic is an effective therapeutic agent for the treatment of patients with refractory or relapsed acute promyelocytic leukemia. The use of arsenic for treating solid tumors, particularly in combination with other chemotherapeutic agents, has been extensively studied. Here, we report that arsenite-resistant human lung cancer CL3R15 cells constitutively overexpress NAD(P)H quinone oxidoreductase 1 (NQO1), an enzyme responsible for activation of mitomycin C (MMC), and are more susceptible to MMC cytotoxicity than parental CL3 cells. The effects of arsenite pretreatment on NQO1 induction were examined in CL3, H1299, H460, and MC-T2 cells. Arsenite pretreatment significantly enhanced the expression of NQO1 and susceptibility to MMC in CL3, H1299, and MC-T2 cells, but not in H460 cells that express high endogenous levels of NQO1. Alternatively, arsenic pretreatment reduced adriamycin sensitivity of CL3 cells. Arsenite-mediated MMC susceptibility was abrogated by dicumarol (DIC), an NQO1 inhibitor, indicating that NQO1 is one of the key regulators of arsenite-mediated MMC susceptibility. Various cancer cell lines showed different basal levels of NQO1 activity and a different capacity for NQO1 induction in response to arsenite treatment. However, overall, there was a positive correlation between induced NQO1 activity and MMC susceptibility in cells pretreated with various doses of arsenite. These results suggest that arsenite may increase NQO1 activity and thus enhance the antineoplastic activity of MMC. In addition, our results also showed that inhibition of NQO1 activity by DIC reversed the arsenite resistance of CL3R15 cells.
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PMID:Arsenite pretreatment enhances the cytotoxicity of mitomycin C in human cancer cell lines via increased NAD(P)H quinone oxidoreductase 1 expression. 1649 10

Available data indicate that there are significant differences in individual susceptibility to lung cancer within the human population. It is believed to be underlie by inherited genetic predispositions related to the genetic polymorphism of several enzymes involved in the detoxification and xenobiotic metabolism. In this review, we collect and discuss the evidence reported up to date on the association between lung cancer and genetic polymorphism of cytochromes P450, N-acetyltransferase, glutathione S-transferases, microsomal epoxide hydrolase, NAD(P)H:quinone oxidoreductase, myeloperoxidase and glutathione peroxidase. All these genes might appear to be candidates for lung cancer susceptibility genes, nevertheless, the present state of the art still offers only a limited explanation of the link between such polymorphisms and increased risk of lung cancer.
Lung Cancer 2007 Jul
PMID:Polymorphism of selected enzymes involved in detoxification and biotransformation in relation to lung cancer. 1733 85

Various molecular epidemiological studies have been performed to find genetic etiology for lung cancer. Particularly, genetic polymorphisms in NAD(P)H-quinone oxidoreductase (NQO1), cytochrome P450 (CYP)1A1, myeloperoxidase (MPO), glutathione-S-transferase (GST)P1, GSTT1, and GSTM1, and have been suspected to affect lung cancer risk. However, there was no study that examined the combined effects of these genes on lung cancer risk. We studied the combined genetic effects on lung cancer risk in 671 Korean subjects including 318 lung cancer patients and 353 controls. They filled questionnaires, which included lifestyle and childhood- and current environment data. Based on single nucleotide polymorphisms and gene deletions, genetic polymorphisms of the above six genes were determined with PCR-RFLP and TaqMan methods. As results, genetic polymorphisms in the GSTP1, MPO, and CYP1A1 among the genetic factors showed associations with lung cancer risk. The reference, which is supposed to have the lowest risk for cancer, was subjects who were homozygous wild type of the GSTP1 and CYP1A1 and had the MPO- mutant allele. After combination study of the three gene-polymorphism, the subjects who were most different with the reference, i.e. had the mutant allele of the GSTP1 and CYP1A1 and homozygous wild type of the MPO, showed approximately 5-fold-higher risk for lung cancer than the reference (95% CI, 2.05-12.05). Therefore, our study suggests that the combination of the GSTP1, MPO, and CYP1A1 variations affects susceptibility to lung cancer.
Lung Cancer 2007 Aug
PMID:Combined effects of genetic polymorphisms in six selected genes on lung cancer susceptibility. 1742 72

Lung cancer is the number one cause of cancer-related deaths in the world. Patients treated with current chemotherapies for non-small-cell lung cancers (NSCLCs) have a survival rate of approximately 15% after 5 years. Novel approaches are needed to treat this disease. We show elevated NAD(P)H:quinone oxidoreductase-1 (NQO1) levels in tumors from NSCLC patients. beta-Lapachone, an effective chemotherapeutic and radiosensitizing agent, selectively killed NSCLC cells that expressed high levels of NQO1. Isogenic H596 NSCLC cells that lacked or expressed NQO1 along with A549 NSCLC cells treated with or without dicoumarol, were used to elucidate the mechanism of action and optimal therapeutic window of beta-lapachone. NSCLC cells were killed in an NQO1-dependent manner by beta-lapachone (LD50, approximately 4 microM) with a minimum 2-h exposure. Kinetically, beta-lapachone-induced cell death was characterized by the following: (i) dramatic reactive oxygen species (ROS) formation, eliciting extensive DNA damage; (ii) hyperactivation of poly(ADP-ribose)polymerase-1 (PARP-1); (iii) depletion of NAD+/ATP levels; and (iv) proteolytic cleavage of p53/PARP-1, indicating mu-calpain activation and apoptosis. Beta-lapachone-induced PARP-1 hyperactivation, nucleotide depletion, and apoptosis were blocked by 3-aminobenzamide, a PARP-1 inhibitor, and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM), a Ca2+ chelator. NQO1- cells (H596, IMR-90) or dicoumarol-exposed NQO1+ A549 cells were resistant (LD50, >40 microM) to ROS formation and all cytotoxic effects of beta-lapachone. Our data indicate that the most efficacious strategy using beta-lapachone in chemotherapy was to deliver the drug in short pulses, greatly reducing cytotoxicity to NQO1- "normal" cells. beta-Lapachone killed cells in a tumorselective manner and is indicated for use against NQO1+ NSCLC cancers.
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PMID:An NQO1- and PARP-1-mediated cell death pathway induced in non-small-cell lung cancer cells by beta-lapachone. 1760 80


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