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)

Phase I and Phase II xenobiotic-metabolising enzyme families are involved in the metabolic activation and detoxification of various classes of environmental carcinogens. Particular genetic polymorphisms of these enzymes have been shown to influence individual cancer risk. A brief overview is presented about recent research of the relationship between metabolic genotypes and internal dose, biologically effective dose and cytogenetic effects of complex and specific genotoxic exposures of human study populations, and we report our new results from two molecular epidemiological studies. We investigated the effects of multiple interactions among CYP1A1 Ile462Val, CYP1A1 MspI, CYP1B1 Leu432Val, CYP2C9 Arg144Cys, CYP2C9 Ile359Leu, NQO1 Pro189Ser, GSTM1 gene deletion and GSTP1 Ile105Val genotypes on the levels of carcinogen-DNA adducts determined by (32)P-postlabelling and PAH-DNA immunoassay in peripheral blood lymphocytes from workers occupationally exposed to polycyclic aromatic hydrocarbons in aluminium plants, and in bronchial tissue from smoking lung patients. A statistically significant positive linear correlation was observed between white blood cell aromatic DNA adduct and urinary 1-hydroxypyrene (1-OHPY) levels from potroom workers with GSTM1 null genotype (P=0.011). Our results suggest interactions between GSTM1 and GSTP1 alleles in modulation of urinary 1-OHPY levels and white blood cell DNA adduct levels in the PAH-exposed workers. Interactions between GSTM1 and GSTP1 alleles, in association with particular genotype combinations of CYPs, were also recognised in bronchial aromatic DNA adduct levels of smoking lung patients. The impact of single metabolic genotypes and their combinations on biomarkers of exposure was usually weak, if any, in both our studies and reports of the literature. The effect of special metabolic gene interactions may be better recognised if the compared groups of individuals are stratified for multiple potential modulators of the observable biomarker end-point, and/or if chemical structure-specific biomarker methods are applied.
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PMID:Impact of metabolic genotypes on levels of biomarkers of genotoxic exposure. 1153 49

Susceptibility to colorectal cancer, one of the most common forms of cancer in the Western world, has been associated with several environmental and dietary risk factors. Dietary exposure to food derived heterocyclic amine carcinogens and polycyclic aromatic hydrocarbons have been proposed as specific risk factors. Many polymorphic Phase I and Phase II drug metabolizing enzymes are responsible for the metabolism and disposition of these compounds and it is therefore possible that inheritance of specific allelic variants of these enzymes may influence colorectal cancer susceptibility. In a multicenter case-control study, 490 colorectal cancer patients and 593 controls (433 matched case-control pairs) were genotyped for common polymorphisms in the cytochrome P450 (CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2C9, CYP2C19 and CYP2D6), glutathione S-transferase (GSTM1, GSTP1 and GSTT1), sulfotransferase (SULT1A1 and SULT1A2), N-acetyl transferase 2 (NAT2), NAD(P)H:quinone oxidoreductase (NQO1), methylenetetrahydrofolate reductase (MTHFR), and microsomal epoxide hydrolase (EPHX1) genes. Matched case-control analysis identified alleles associated with higher colorectal cancer risk as carriage of CYP1A1*2C (OR = 2.15, 95% CI 1.36-3.39) and homozygosity for GSTM1*2/*2 (OR = 1.53, 95% CI 1.16-2.02). In contrast, inheritance of the CYP2A6*2 (OR = 0.51, 95% CI 0.28-1.06), CYP2C19*2 (OR = 0.72, 95% CI 0.52-0.98) and the EPHX1(His113) alleles were associated with reduced cancer risk. We found no association with colorectal cancer risk with NAT2 genotype or any of the other polymorphic genes associated with the metabolism and disposition of heterocyclic amine carcinogens. This data suggests that heterocyclic amines do not play an important role in the aetiology of colorectal cancer but that exposure to other carcinogens such as polycyclic aromatic hydrocarbons may be important determinants of cancer risk.
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PMID:A pharmacogenetic study to investigate the role of dietary carcinogens in the etiology of colorectal cancer. 1241 32

We present an oligonucleotide microarray ("MetaboChip") based on the arrayed primer extension (APEX) technique, allowing genotyping of single nucleotide polymorphisms (SNPs) in genes of interest for cancer susceptibility and pharmacogenetics. APEX consists of a sequencing reaction primed by an oligonucleotide anchored with its 5' end to a glass slide and terminating one nucleotide before the polymorphic site. The extension with one fluorescently labeled dideoxynucleotide complementary to the template reveals the polymorphism. Ninety-three SNPs in 42 genes were selected among those resequenced in the context of the SNP500 project, using a set of 102 reference DNA samples from the Coriell Biorepository. Selected SNPs belong to the following genes: ADH1B, ALDH2, APEX, CDKN2A, COMT, CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2C19, CYP2C9, CYP2E1, CYP3A4, DRD2, DRD4, EPHX1, ERCC1, ERCC2, ERCC4, ERCC5, GRPR, GSTA4, GSTM3, GSTP1, GSTT2, LIG3, MDM2, MGMT, MPO, NAT1, NAT2, NQO1, OGG1, PCNA, POLB, SLC6A3, SOD2, TP53, XRCC1, XRCC2, XRCC3, and XRCC9. We assessed the performance of APEX by comparing the results obtained with MetaboChip against those reported by the SNP500. Among 88 SNPs that yielded signals, 6 showed less than 99% of concordance, whereas 82 performed accurately, showing that APEX is a reliable and sensitive genotyping method.
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PMID:Evaluation of a microarray for genotyping polymorphisms related to xenobiotic metabolism and DNA repair. 1457 48

Knowledge of genetic polymorphisms in gene-environment studies may contribute to more accurate identification of avoidable risks and to developing tailor-made preventative measures. The aim of this study was to describe the allele frequencies of single nucleotide polymorphisms (SNPs) of select genes, which may be included in future gene-environment studies on cancer in Japan. SNP typing was performed on middle-aged Japanese men randomly selected from the general population in five areas of Japan. We genotyped and calculated allele frequencies of 153 SNPs located on 40 genes: CYP1A1, CYP1B1, CYP2C9, CYP2C19, CYP2E1, CYP17A1, CYP19A1, AHR, ESR1, ESR2, ERRRG, PGR, EPHX1, EPHX2, HSD17B2, HSD17B3, GSTM2, GSTM3, GSTT2, GSTP1, NAT1, NAT2, COMT, ADH1A, ADH1B, ADH1C, ALDH2, NOS2A, NOS3, IL1A, IL1B, OGG1, NUDT1 [MTH1], DRD2, DRD3, DRD4, SLC6A4, NR3C1 [GCCR], MTHFR, and NQO1. In the present study, the Japanese allele frequencies were verified by using nationwide population samples.
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PMID:Allele frequencies of single nucleotide polymorphisms (SNPs) in 40 candidate genes for gene-environment studies on cancer: data from population-based Japanese random samples. 1463 38

Genes involved in metabolism of environmental chemical exposures exhibit sequence variability that may mediate the risk of non-Hodgkin's lymphoma. We evaluated associations between non-Hodgkin's lymphoma and 15 variants in AHR, CYP1A1, CYP1A2, CYP1B1, CYP2C9, CYP2E1, GSTP1, GSTM3, EPHX1, NQO1, and PON1. Cases were identified from four Surveillance, Epidemiology, and End Results registries in the United States, and population-based controls were identified through random-digit dialing and Medicare eligibility files. Metabolic gene variants were characterized for the 1,172 (89% of total) cases and 982 (93%) controls who provided biological samples for genotyping. Subjects who were heterozygous or homozygous for the cytochrome P450 gene variant CYP1B1 V432L G allele were at slightly greater risk of non-Hodgkin's lymphoma [odds ratio (OR), 1.27; 95% confidence interval (95% CI), 0.97-1.65]; these results were consistent across B-cell lymphoma subtypes and among both non-Hispanic White and Black subjects, although not statistically significant. The CYP2E1 -1054T allele was associated with decreased risk of non-Hodgkin's lymphoma (CT and TT genotypes combined OR, 0.59; 95% CI, 0.37-0.93), and this pattern was observed among all histologic subtypes. The numbers of cases of particular subtypes were rather small for stable estimates, but we noted that the PON1 L55M AA allele, associated with slightly increased risk of non-Hodgkin's lymphoma (variant homozygotes OR, 1.36; 95% CI, 0.96-1.95), was most strongly associated with follicular non-Hodgkin's lymphoma and T-cell lymphoma, with ORs for variant homozygotes of 2.12 and 2.93, respectively. There was no overall association with non-Hodgkin's lymphoma for the other gene variants we examined. The modest effects we observed may reflect the context of exposures within the general population represented in our study.
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PMID:Metabolic gene variants and risk of non-Hodgkin's lymphoma. 1698 26

Polymorphisms in genes coding xenobiotic-metabolizing enzymes are considered as risk factors modifying susceptibility to cancer. We developed a biochip for the analysis of 18 mutations in 10 genes of metabolizing system: CYP1A1, CYP2D6, GSTT1, GSTM1, MTHFR, MTRR, NQO1, CYP2C9, CYP2C19, and NAT2. Using allele-specific hybridization on the biochip 76 T-cell non-Hodgkin's lymphoma (NHL) patients, 83 B-cell chronic lymphocytic leukemia (B-CLL) patients, and 177 healthy donors were tested. Polymorphic CYP1A1 alleles were more frequent in B-CLL patients relative to normal controls, for example, a combination of polymorphic variants 4887C > A, 4889A > G, and 6235T > C (OR = 1.76, 95% CI = 1.0-3.1). The GSTM1 null genotype was more frequent in NHL patients relative to controls (OR = 1.82, 95% CI = 1.1-3.1). The combination of unfavorable polymorphic CYP1A1 variants and GSTM1 null genotype was found more frequently in B-CLL patients relative to controls (OR = 2.52, 95% CI = 1.3-4.9). In addition, male B-CLL patients demonstrated a significantly increased occurrence of heterozygous and homozygous allele *2 of CYP2C9 gene (OR = 2.38, 95% CI = 1.1-5.2) as well as a combination of alleles *2 and *3 of the gene (OR = 2.09, 95% CI = 1.1-3.9). Thus, our findings show the association between polymorphic alleles of CYP1A1, GSTM1, and CYP2C9 genes and the risk to develop NHL or B-CLL. The developed biochip can be considered as a convenient analytical tool for research studies and predictive analysis in oncohematology.
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PMID:Polymorphisms in xenobiotic-metabolizing genes and the risk of chronic lymphocytic leukemia and non-Hodgkin's lymphoma in adult Russian patients. 1806 41

Estrogen and its metabolites are believed to play important roles in breast cancer, and its determinants include both genetic and lifestyle factors. The objective of the study is to investigate the association of breast cancer risk in Thailand with genetic polymorphisms in several genes involved in estrogen synthesis and metabolism. Five hundred and seventy patients with histopathologically confirmed breast cancer and 497 controls were included in the present study. Forty single nucleotide polymorphisms (SNPs) in the CYP1A1, CYP1A2, CYP1B1, CYP17, CYP19, CYP2C9, CYP2C19, AhR, ESR1, PGR, ERRG, COMT, HSD17B1, HSD17B2, EPHX1 and NQO1 genes were genotyped. Association of genotypes with breast cancer risk was evaluated using multivariate logistic regression, which suggested an altered risk for the following SNPs [gene, odds ratio (OR) and 95% confidence interval are shown]: heterozygote carriers of rs4917623 [CYP2C19, OR = 1.38 (1.04-1.84)], rs2066853 [AhR, OR = 1.34 (1.02-1.76)] and rs1857407 [ERRG, (OR = 0.72 (0.55-0.96)]; homozygote carriers of rs762551 [CYP1A2, OR = 2.75 (1.47-5.14)], rs4917623 [CYP2C19, OR = 1.48 (1.00-2.19) and rs945453 [ERRG, OR = 1.66 (1.04-2.65)]. In addition, a stratified analysis by menopausal status indicated that the association of the CYP1A2 (rs762551) and CYP17 (rs743572) polymorphisms with breast cancer risk were mainly evident in premenopausal, while ERRG (rs1857407) was significant in postmenopausal women. These findings suggest that CYP1A2, CYP2C19, AhR, ERRG and CYP17 polymorphisms may play an important role in estrogen metabolism and modify individual susceptibility to breast cancer in Thai women.
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PMID:Genetic polymorphisms of estrogen metabolizing enzyme and breast cancer risk in Thai women. 1941 45

A substantial part of the interindividual variability in response to drugs and xenobiotics is related to genetically-determined impairment in drug metabolism. Several drug-metabolising enzymes are polymorphic in humans and often polymorphisms are strongly related to altered drug biodisposition and to the risk of developing adverse effects. Drugs used in general anaesthesia undergo polymorphic metabolism. Among these, halothane is metabolized by cytochrome P450 (CYP) 2E1 and, to a lesser extent, by CYP3A4 and CYP2A6. CYP2E1 also plays a key role in the metabolism of isoflurane, sevoflurane, enflurane and desflurane. CYP2B6, CYP3A4 and CYP2C9 play a relevant role in the metabolism of ketamine. The enzymes involved in the metabolism of thiopental and etomidate remains to be elucidated. Propofol is metabolized mainly by glucuronidation by uridine diphosphate-glucuronosyltransferases (UGTs) and by hydroxylation by CYP2B6 and CYP2C enzymes. The enzymes SULT1A1 and NQO1 participate in later steps in propofol metabolism. All the above-mentioned anaesthetic-metabolising enzymes are polymorphic in man. The present review analyzes the importance of enzymes in the metabolism of anaesthetics and common polymorphisms related to the biotransformation of general anaesthetics and it raises hypotheses on genetic and non-genetics factors related to altered response to anaesthetics that require further investigation. Based on functional relevance and allele frequencies, we identify the most promising targets for the clinical use of pharmacogenomic techniques in anaesthesia to prevent altered pharmacokinetics or adverse drug effects.
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PMID:Polymorphic drug metabolism in anaesthesia. 1944 86

Xenobiotic-metabolizing genes (e.g., Cytochromes P450, GST, NAT2, and NQO1), folate metabolism genes (e.g., MTHFR and MTRR), and major histocompatibility complex genes (e.g., HLA-DQA1) play multiple roles in the organism functioning. In addition, AB0 is the most clinically significant high-polymorphic gene in transfusion and transplantation medicine. Epidemiological data show that allele frequencies of these genes exhibit ethnic and geographic diversity. Besides, little is known about frequency distribution of the major polymorphic variants in native Russians. We developed biological microchips that allow us to analyze a spectrum of allelic variants in 12 different genes: CYP1A1, CYP2D6, CYP2C9, CYP2C19, GSTT1, GSTM1, MTHFR, MTRR, NQO1, NAT2, HLA-DQA1, and AB0. Using this composite methodological platform we have studied 352 DNA samples from healthy native Russian volunteers. The allelic frequencies of gene polymorphisms obtained are close to allelic frequencies observed in some European populations, as published earlier. These data were used in comparative studies to determine predisposition to tuberculosis, lymphoma, and leukemia in adults and to childhood acute leukemia. The HLA-DQA1 and AB0 allele frequencies were used to estimate forensic population parameters for these loci.
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PMID:Microarray-based detection of CYP1A1, CYP2C9, CYP2C19, CYP2D6, GSTT1, GSTM1, MTHFR, MTRR, NQO1, NAT2, HLA-DQA1, and AB0 allele frequencies in native Russians. 2037 52

In developed countries cardiovascular disease is one of the leading causes of death. Cardiovascular drugs such as platelet aggregation inhibitors, oral anticoagulants, antihypertensives and cholesterol lowering drugs are abundantly prescribed to reduce risk of cardiovascular disease. Notable interindividual variation exists in the response to these pharmacotherapeutic interventions, which can be partially explained by factors such as gender, age, diet, concomitant drug use and environmental factors. Notwithstanding, a great part of this variability remains unknown. To a smaller or larger extent, genetic variability may contribute to the variability in response to these cardiovascular drugs. This review gives an overview of pharmacogenetic studies of genes that were reported to be associated with four commonly prescribed drugs/drug classes (platelet aggregation inhibitors, coumarins, antihypertensives and statins) and were studied at least 2 times with a similar outcome measure. In the field of cardiovascular drug therapy, polymorphisms in candidate genes such as the cycloxygenase-1, vitamin K reductase complex subunit 1, CYP2C9, alpha adducin and 3-hydroxy-3-methylglutaryl-CoA reductase have received a great amount of interest in the pharmacogenetics of aspirin, coumarins, antihypertensives and statins respectively. However, only variations in VKORC1 and CYP2C9 have consistently been associated with drug response (coumarins) and have clinical implications. Clinical trials should provide evidence for the effectiveness of genotyping before this procedure will be a part of every day anticoagulant therapy. In spite of the tremendous amount of publications in this field, there is no reason to advocate for genetic testing for any other drugs cardiovascular drug therapy yet. Current approaches in pharmacogenetic research do not seem to lead to results that meet our expectations of individualized medicine. Therefore, new approaches are needed addressing issues and challenges such as the number of SNPs studied, study power, study design and application of new statistical methods in (pharmaco-)genetic analysis.
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PMID:Pharmacogenetics of cardiovascular drug therapy. 2246 Oct 99


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