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Thomas L, Raju AP, Mallayasamy S, Rao M. Precision Medicine Strategies to Improve Isoniazid Therapy in Patients with Tuberculosis. Eur J Drug Metab Pharmacokinet 2024:10.1007/s13318-024-00910-7. [PMID: 39153028 DOI: 10.1007/s13318-024-00910-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2024] [Indexed: 08/19/2024]
Abstract
Due to interindividual variability in drug metabolism and pharmacokinetics, traditional isoniazid fixed-dose regimens may lead to suboptimal or toxic isoniazid concentrations in the plasma of patients with tuberculosis, contributing to adverse drug reactions, therapeutic failure, or the development of drug resistance. Achieving precision therapy for isoniazid requires a multifaceted approach that could integrate various clinical and genomic factors to tailor the isoniazid dose to individual patient characteristics. This includes leveraging molecular diagnostics to perform the comprehensive profiling of host pharmacogenomics to determine how it affects isoniazid metabolism, such as its metabolism by N-acetyltransferase 2 (NAT2), and studying drug-resistant mutations in the Mycobacterium tuberculosis genome for enabling targeted therapy selection. Several other molecular signatures identified from the host pharmacogenomics as well as other omics-based approaches such as gut microbiome, epigenomic, proteomic, metabolomic, and lipidomic approaches have provided mechanistic explanations for isoniazid pharmacokinetic variability and/or adverse drug reactions and thereby may facilitate precision therapy of isoniazid, though further validations in larger and diverse populations with tuberculosis are required for clinical applications. Therapeutic drug monitoring and population pharmacokinetic approaches allow for the adjustment of isoniazid dosages based on patient-specific pharmacokinetic profiles, optimizing drug exposure while minimizing toxicity and the risk of resistance. Current evidence has shown that with the integration of the host pharmacogenomics-particularly NAT2 and Mycobacterium tuberculosis genomics data along with isoniazid pharmacokinetic concentrations in the blood and patient factors such as anthropometric measurements, comorbidities, and type and timing of food administered-precision therapy approaches in isoniazid therapy can be tailored to the specific characteristics of both the host and the pathogen for improving tuberculosis treatment outcomes.
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Affiliation(s)
- Levin Thomas
- Department of Pharmacy Practice, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India
| | - Arun Prasath Raju
- Department of Pharmacy Practice, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India
| | - Surulivelrajan Mallayasamy
- Department of Pharmacy Practice, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India
| | - Mahadev Rao
- Department of Pharmacy Practice, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India.
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2
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Delabays B, Trajanoska K, Walonoski J, Mooser V. Cardiovascular Pharmacogenetics: From Discovery of Genetic Association to Clinical Adoption of Derived Test. Pharmacol Rev 2024; 76:791-827. [PMID: 39122647 DOI: 10.1124/pharmrev.123.000750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 04/24/2024] [Accepted: 05/28/2024] [Indexed: 08/12/2024] Open
Abstract
Recent breakthroughs in human genetics and in information technologies have markedly expanded our understanding at the molecular level of the response to drugs, i.e., pharmacogenetics (PGx), across therapy areas. This review is restricted to PGx for cardiovascular (CV) drugs. First, we examined the PGx information in the labels approved by regulatory agencies in Europe, Japan, and North America and related recommendations from expert panels. Out of 221 marketed CV drugs, 36 had PGx information in their labels approved by one or more agencies. The level of annotations and recommendations varied markedly between agencies and expert panels. Clopidogrel is the only CV drug with consistent PGx recommendation (i.e., "actionable"). This situation prompted us to dissect the steps from discovery of a PGx association to clinical translation. We found 101 genome-wide association studies that investigated the response to CV drugs or drug classes. These studies reported significant associations for 48 PGx traits mapping to 306 genes. Six of these 306 genes are mentioned in the corresponding PGx labels or recommendations for CV drugs. Genomic analyses also highlighted the wide between-population differences in risk allele frequencies and the individual load of actionable PGx variants. Given the high attrition rate and the long road to clinical translation, additional work is warranted to identify and validate PGx variants for more CV drugs across diverse populations and to demonstrate the utility of PGx testing. To that end, pre-emptive PGx combining genomic profiling with electronic medical records opens unprecedented opportunities to improve healthcare, for CV diseases and beyond. SIGNIFICANCE STATEMENT: Despite spectacular breakthroughs in human molecular genetics and information technologies, consistent evidence supporting PGx testing in the cardiovascular area is limited to a few drugs. Additional work is warranted to discover and validate new PGx markers and demonstrate their utility. Pre-emptive PGx combining genomic profiling with electronic medical records opens unprecedented opportunities to improve healthcare, for CV diseases and beyond.
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Affiliation(s)
- Benoît Delabays
- Canada Excellence Research Chair in Genomic Medicine, Victor Phillip Dahdaleh Institute of Genomic Medicine, Department of Human Genetics, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada (B.D., K.T., V.M.); and Medeloop Inc., Palo Alto, California, and Montreal, QC, Canada (J.W.)
| | - Katerina Trajanoska
- Canada Excellence Research Chair in Genomic Medicine, Victor Phillip Dahdaleh Institute of Genomic Medicine, Department of Human Genetics, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada (B.D., K.T., V.M.); and Medeloop Inc., Palo Alto, California, and Montreal, QC, Canada (J.W.)
| | - Joshua Walonoski
- Canada Excellence Research Chair in Genomic Medicine, Victor Phillip Dahdaleh Institute of Genomic Medicine, Department of Human Genetics, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada (B.D., K.T., V.M.); and Medeloop Inc., Palo Alto, California, and Montreal, QC, Canada (J.W.)
| | - Vincent Mooser
- Canada Excellence Research Chair in Genomic Medicine, Victor Phillip Dahdaleh Institute of Genomic Medicine, Department of Human Genetics, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada (B.D., K.T., V.M.); and Medeloop Inc., Palo Alto, California, and Montreal, QC, Canada (J.W.)
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3
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Drain PK. Another Step Closer to Genomic-informed Therapeutic Dosing for Tuberculosis Drugs. Am J Respir Crit Care Med 2024; 209:1427-1428. [PMID: 38648185 PMCID: PMC11208968 DOI: 10.1164/rccm.202403-0566ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 04/19/2024] [Indexed: 04/25/2024] Open
Affiliation(s)
- Paul K Drain
- Department of Global Health Department of Medicine
- Department of Epidemiology University of Washington Seattle, Washington
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4
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Lagrange E, Loriot MA, Chaudhary NK, Schultz P, Dirks AC, Guissart C, James TY, Vernoux JP, Camu W, Tripathi A, Spencer PS. Corrected speciation and gyromitrin content of false morels linked to ALS patients with mostly slow-acetylator phenotypes. eNeurologicalSci 2024; 35:100502. [PMID: 38770222 PMCID: PMC11103407 DOI: 10.1016/j.ensci.2024.100502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/22/2024] [Accepted: 05/03/2024] [Indexed: 05/22/2024] Open
Abstract
A case-control study of sporadic amyotrophic lateral sclerosis (ALS) in a mountainous village in the French Alps discovered an association of cases with a history of eating wild fungi (false morels) collected locally and initially identified and erroneously reported as Gyromitra gigas. Specialist re-examination of dried specimens of the ALS-associated fungi demonstrated they were members of the G. esculenta group, namely G. venenata and G. esculenta, species that have been reported to contain substantially higher concentrations of gyromitrin than present in G. gigas. Gyromitrin is metabolized to monomethylhydrazine, which is responsible not only for the acute oral toxic and neurotoxic properties of false morels but also has genotoxic potential with proposed mechanistic relevance to the etiology of neurodegenerative disease. Most ALS patients had a slow- or intermediate-acetylator phenotype predicted by N-acetyltransferase-2 (NAT2) genotyping, which would increase the risk for neurotoxic and genotoxic effects of gyromitrin metabolites.
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Affiliation(s)
- Emmeline Lagrange
- Department of Neurology, Reference Center of Neuromuscular Disease and ALS Consultations, Grenoble University Hospital, Grenoble, France
| | - Marie-Anne Loriot
- Department of Clinical Chemistry, European Georges-Pompidou hospital, Assistance Publique–Hôpitaux de Paris, University Paris Cité, INSERM UMR-S1138, Centre de Recherches des Cordeliers, 75908 Paris Cedex 15, France
| | - Nirmal K. Chaudhary
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pam Schultz
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alden C. Dirks
- Department of Ecology and Evolution, University of Michigan, Ann Arbor, MI 48109, USA
| | - Claire Guissart
- Laboratoire de Biochimie et Biologie Moleculaire, CHU Nimes, Nimes, Motoneuron Disease: Pathophysiology and Therapy, INM, Univ. Montpellier, Montpellier, France
| | - Timothy Y. James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jean Paul Vernoux
- Unité de Recherche Aliments Bioprocédés Toxicologie Environnements (ABTE) EA 4651, Normandie University, UNICAEN, 14000 Caen, France
| | - William Camu
- NM, Université Montpellier, INSERM, CNRS, Montpellier, France
| | - Ashootosh Tripathi
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan, 48109, USA
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5
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Tiis RP, Osipova LP, Galieva ER, Lichman DV, Voronina EN, Melikhova AV, Orlov YL, Filipenko ML. [N-aсetyltransferase (NAT2) gene polymorphism and gene network analysis]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2021; 67:213-221. [PMID: 34142528 DOI: 10.18097/pbmc20216703213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To search for new targets of therapy, it is necessary to reconstruct the gene network of the disease, and identify the interaction of genes, proteins, and drug compounds. Using the online bioinformatics tools we have analyzed the current data set related to the metabolism of xenobiotics, mediated by the N-acetyltransferase 2 (NAT2) gene. The study of allelic polymorphism of the NAT2 gene has a prognostic value, allowing to determine the risk of a number of oncological diseases, the degree of increased risk due to smoking and exposure to chemical carcinogens, including drugs. The aim of this study was to determine the frequencies of two important "slow" variants of the NAT2 gene (NAT2*5, rs1801280 and NAT2*7, rs1799931), which significantly affected the rate of xenobiotic acetylation among the indigenous Nenets population of Northern Siberia. The obtained frequencies of polymorphic variants among the Nenets occupy an intermediate value between those for Europeans and Asians, which might indicate specific features of adaptation. We present a model of the distribution of two polymorphic variants of the NAT2 gene involved in the biotransformation of xenobiotics to study the characteristics of their metabolism in the indigenous inhabitants of Yamal.
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Affiliation(s)
- R P Tiis
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia
| | - L P Osipova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia
| | - E R Galieva
- Novosibirsk State University, Novosibirsk, Russia
| | - D V Lichman
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia
| | - E N Voronina
- Novosibirsk State University, Novosibirsk, Russia; Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A V Melikhova
- Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Moscow, Russia
| | - Y L Orlov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia; I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Moscow, Russia
| | - M L Filipenko
- Novosibirsk State University, Novosibirsk, Russia; Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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6
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Abstract
Drug metabolizing enzymes catalyze the biotransformation of many of drugs and chemicals. The drug metabolizing enzymes are distributed among several evolutionary families and catalyze a range of detoxication reactions, including oxidation/reduction, conjugative, and hydrolytic reactions that serve to detoxify potentially toxic compounds. This detoxication function requires that drug metabolizing enzymes exhibit substrate promiscuity. In addition to their catalytic functions, many drug metabolizing enzymes possess functions unrelated to or in addition to catalysis. Such proteins are termed 'moonlighting proteins' and are defined as proteins with multiple biochemical or biophysical functions that reside in a single protein. This review discusses the diverse moonlighting functions of drug metabolizing enzymes and the roles they play in physiological functions relating to reproduction, vision, cell signaling, cancer, and transport. Further research will likely reveal new examples of moonlighting functions of drug metabolizing enzymes.
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Affiliation(s)
- Philip G Board
- John Curtin School of Medical Research, ANU College of Health and Medicine, The Australian National University, Canberra, ACT, Australia
| | - M W Anders
- Department of Pharmacology and Physiology, University of Rochester Medical Center, New York, NY, USA
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7
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Swart C, Meldau S, Centner CM, Marais AD, Omar F. Validation of PHASE for deriving N-acetyltransferase 2 haplotypes in the Western Cape mixed ancestry population. Afr J Lab Med 2020; 9:988. [PMID: 33392048 PMCID: PMC7756977 DOI: 10.4102/ajlm.v9i1.988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 09/14/2020] [Indexed: 11/17/2022] Open
Abstract
Background There is a shortage of data on the accuracy of statistical methods for the prediction of N-acetyltransferase 2 (NAT2) haplotypes in the mixed ancestry population of the Western Cape. Objective This study aimed to identify the NAT2 haplotypes and assess the accuracy of PHASE version 2.1.1 in assigning NAT2 haplotypes to a mixed ancestry population from the Western Cape. Methods This study was conducted between 2013 and 2016. The NAT2 gene was amplified and sequenced from the DNA of 100 self-identified mixed ancestry participants. Haplotyping was performed by molecular and computational techniques. Agreement was assessed between the two techniques. Results Haplotypes were assigned to 93 samples, of which 67 (72%) were ambiguous. Haplotype prediction by PHASE demonstrated 94.6% agreement (kappa 0.94, p < 0.001) with those assigned using molecular techniques. Five haplotype combinations (from 10 chromosomes) were incorrectly predicted, four of which were flagged as uncertain by the PHASE software. Only one resulted in the assignment of an incorrect acetylation phenotype (intermediate to slow), although the software flagged this for further analysis. The most common haplotypes were NAT2*4 (28%) followed by NAT2*5B (27.4%), NAT2*6A (21.5%) and NAT2*12A (7.5%). Four rare single nucleotide variants (c.589C>T, c.622T>C, c.809T>C and c.387C>T) were detected. Conclusion PHASE accurately predicted the phenotype in 92 of 93 samples (99%) from genotypic data in our mixed ancestry sample population, and is therefore a suitable alternative to molecular methods to individualise isoniazid therapy in this high burden tuberculosis setting.
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Affiliation(s)
- Celeste Swart
- Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,National Health Laboratory Service (NHLS), Groote Schuur Hospital, Cape Town, South Africa
| | - Surita Meldau
- National Health Laboratory Service (NHLS), Groote Schuur Hospital, Cape Town, South Africa.,Division of Chemical Pathology, University of Cape Town, Cape Town, South Africa
| | - Chad M Centner
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa.,National Health Laboratory Service (NHLS), Medical Microbiology, Groote Schuur Hospital, Cape Town, South Africa
| | - Adrian D Marais
- Division of Chemical Pathology, University of Cape Town, Cape Town, South Africa
| | - Fierdoz Omar
- Division of Chemical Pathology, University of Cape Town, Cape Town, South Africa
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8
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Human arylamine N-acetyltransferase 2 genotype-dependent protein expression in cryopreserved human hepatocytes. Sci Rep 2020; 10:7566. [PMID: 32372066 PMCID: PMC7200704 DOI: 10.1038/s41598-020-64508-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/16/2020] [Indexed: 01/08/2023] Open
Abstract
Human N-acetyltransferases (NAT; EC 2.3.1.5) catalyze the N-acetylation of arylamine and hydrazine drugs and the O-acetylation of N-hydroxylated metabolites of aromatic and heterocyclic amines. Two different isoforms of this protein, N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2), are expressed in human hepatocytes. Both are encoded by a single 870-bp open reading frame that exhibits genetic polymorphisms in human populations. NAT1 and NAT2 share more than 85% gene and protein sequence, making it challenging to produce antibodies with high specificity for NAT1 or NAT2. In the present study, we compared methods for the quantification of immunoreactive NAT1 and NAT2 with seven different antibodies and investigated the relationship of NAT2 genotype to NAT2 mRNA and protein expression in cryopreserved human hepatocytes. Sulfamethazine (NAT2-selective substrate) and NAT2 protein expression differed significantly with NAT2 acetylator genotype (p < 0.0001). NAT2 protein expression and sulfamethazine NAT2 catalytic activity correlated highly across the cryopreserved human hepatocytes of rapid, intermediate, and slow acetylator NAT2 genotypes. In conclusion, our data describe a specific analytical method for the quantification of NAT1 and NAT2 protein expression. We showed that the NAT2 activity in human hepatocytes is directly correlated to expression levels of NAT2 protein but not mRNA.
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9
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Saiz PA, Garcia-Portilla MP, Arango C, Morales B, Alvarez V, Coto E, Fernandez JM, Bousono M, Bobes J. N-acetyltransferase-2 polymorphisms and schizophrenia. Eur Psychiatry 2020; 21:333-7. [PMID: 16529914 DOI: 10.1016/j.eurpsy.2005.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 12/15/2005] [Indexed: 11/22/2022] Open
Affiliation(s)
- Pilar Alejandra Saiz
- School of Medicine, University of Oviedo, Department of Psychiatry, Julian Claveria 6 - 3th, 33006, Oviedo, Asturias, Spain.
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10
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N-Acetyltransferase 2 Genotypes among Zulu-Speaking South Africans and Isoniazid and N-Acetyl-Isoniazid Pharmacokinetics during Antituberculosis Treatment. Antimicrob Agents Chemother 2020; 64:AAC.02376-19. [PMID: 31964788 PMCID: PMC7179278 DOI: 10.1128/aac.02376-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 12/23/2019] [Indexed: 01/06/2023] Open
Abstract
The distribution of N-acetyltransferase 2 gene (NAT2) polymorphisms varies considerably among different ethnic groups. Information on NAT2 single-nucleotide polymorphisms in the South African population is limited. We investigated NAT2 polymorphisms and their effect on isoniazid pharmacokinetics (PK) in Zulu black HIV-infected South Africans in Durban, South Africa. HIV-infected participants with culture-confirmed pulmonary tuberculosis (TB) were enrolled from two unrelated studies. Participants with culture-confirmed pulmonary TB were genotyped for the NAT2 polymorphisms 282C>T, 341T>C, 481C>T, 857G>A, 590G>A, and 803A>G using Life Technologies prevalidated TaqMan assays (Life Technologies, Paisley, UK). Participants underwent sampling for determination of plasma isoniazid and N-acetyl-isoniazid concentrations. Among the 120 patients, 63/120 (52.5%) were slow metabolizers (NAT2*5/*5), 43/120 (35.8%) had an intermediate metabolism genotype (NAT2*5/12), and 12/120 (11.7%) had a rapid metabolism genotype (NAT2*4/*11, NAT2*11/12, and NAT2*12/12). The NAT2 alleles evaluated in this study were *4, *5C, *5D, *5E, *5J, *5K, *5KA, *5T, *11A, *12A/12C, and *12M. NAT2*5 was the most frequent allele (70.4%), followed by NAT2*12 (27.9%). Fifty-eight of 60 participants in study 1 had PK results. The median area under the concentration-time curve from 0 to infinity (AUC0-∞) was 5.53 (interquartile range [IQR], 3.63 to 9.12 μg h/ml), and the maximum concentration (C max) was 1.47 μg/ml (IQR, 1.14 to 1.89 μg/ml). Thirty-four of 40 participants in study 2 had both PK results and NAT2 genotyping results. The median AUC0-∞ was 10.76 μg·h/ml (IQR, 8.24 to 28.96 μg·h/ml), and the C max was 3.14 μg/ml (IQR, 2.39 to 4.34 μg/ml). Individual polymorphisms were not equally distributed, with some being represented in small numbers. The genotype did not correlate with the phenotype, with those with a rapid acetylator genotype showing higher AUC0-∞ values than those with a slow acetylator genotype, but the difference was not significant (P = 0.43). There was a high prevalence of slow acetylator genotypes, followed by intermediate and then rapid acetylator genotypes. The poor concordance between genotype and phenotype suggests that other factors or genetic loci influence isoniazid metabolism, and these warrant further investigation in this population.
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11
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Cicchese JM, Dartois V, Kirschner DE, Linderman JJ. Both Pharmacokinetic Variability and Granuloma Heterogeneity Impact the Ability of the First-Line Antibiotics to Sterilize Tuberculosis Granulomas. Front Pharmacol 2020; 11:333. [PMID: 32265707 PMCID: PMC7105635 DOI: 10.3389/fphar.2020.00333] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis (TB) remains as one of the world's deadliest infectious diseases despite the use of standardized antibiotic therapies. Recommended therapy for drug-susceptible TB is up to 6 months of antibiotics. Factors that contribute to lengthy regimens include antibiotic underexposure in lesions due to poor pharmacokinetics (PK) and complex granuloma compositions, but it is difficult to quantify how individual antibiotics are affected by these factors and to what extent these impact treatments. We use our next-generation multi-scale computational model to simulate granuloma formation and function together with antibiotic pharmacokinetics and pharmacodynamics, allowing us to predict conditions leading to granuloma sterilization. In this work, we focus on how PK variability, determined from human PK data, and granuloma heterogeneity each quantitatively impact granuloma sterilization. We focus on treatment with the standard regimen for TB of four first-line antibiotics: isoniazid, rifampin, ethambutol, and pyrazinamide. We find that low levels of antibiotic concentration due to naturally occurring PK variability and complex granulomas leads to longer granuloma sterilization times. Additionally, the ability of antibiotics to distribute in granulomas and kill different subpopulations of bacteria contributes to their specialization in the more efficacious combination therapy. These results can inform strategies to improve antibiotic therapy for TB.
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Affiliation(s)
- Joseph M Cicchese
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Véronique Dartois
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States.,Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, United States
| | - Denise E Kirschner
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Jennifer J Linderman
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, United States
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12
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Akhter N, Iqbal T, Jamil A, Akram M, Mehmood Tahir I, Munir N. Determination of Arylamine N-Acetyltransferase 2 Acetylation Genotype by PCR and Phenotyping Using Dapsone Through High-Pressure Liquid Chromatography Assay: A Gender Wise Study. Dose Response 2019; 17:1559325819855537. [PMID: 31285712 PMCID: PMC6600507 DOI: 10.1177/1559325819855537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 05/03/2019] [Accepted: 05/07/2019] [Indexed: 11/30/2022] Open
Abstract
The main aim of the study was to establish the acetylation status of local
population of Pakistan by N-acetyltransferase 2 (NAT2) enzyme and to find out
the concordance between phenotypic and genotypic methods for the determination
of NAT2 acetylation. Gender-wise comparison of selected healthy male and female
volunteers aged greater than 18 years was also conducted to see the effect of
sex on NAT2 acetylation. Phenotypically, the rate of acetylation was determined
by high-pressure liquid chromatography with dapsone (DDS) probe drug, while
genotypically, NAT2 acetylation was determined by using specific primers for
NAT2 variant alleles (M1, M2, and M3) amplified in separate polymerase chain
reactions. High-pressure liquid chromatography results indicated 64% of the male
volunteers to be fast acetylators while 36% were slow acetylators, while ratio
of fast and slow acetylators for female was found to be 66% and 34%,
respectively. Genotypically, the ratio of fast and slow for male was 60% and 40%
and for female was 66% and 34%, respectively. The distribution of 3 NAT2 variant
alleles was found in invariable number. For male volunteers, the highest
frequency distribution showed by M2 allele was 56%, while for M1 and M3 the
frequency was 32% and 12%, respectively, and for female volunteers highest
frequency (51%) was shown by the M2 variant allele while lowest frequency (18%)
was shown by M3 allele. There was the 94% concordance between the DDS phenotype
and genotype. Gender effect on the acetylation was found to be nonsignificant
(P > .05). Therefore, it is concluded that NAT2
acetylation rate can be used to check in vivo acetylation status with dapsone as
probe drug. It is concluded that NAT2 acetylation rate was unaffected by gender
and can be used to check in vivo acetylation status with dapsone as probe drug,
which is inexpensive and less time-consuming.
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Affiliation(s)
- Naheed Akhter
- College of Allied Health Professionals, Directorate of Medical Sciences, Government College University, Faisalabad, Pakistan
| | - Tahira Iqbal
- Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan
| | - Amer Jamil
- Department of Biochemistry, Government College University, Faisalabad, Pakistan
| | - Muhammad Akram
- Department of Eastern Medicine and Surgery, Directorate of Medical Sciences, Government College University, Faisalabad, Pakistan
| | - Imtiaz Mehmood Tahir
- College of Allied Health Professionals, Directorate of Medical Sciences, Government College University, Faisalabad, Pakistan
| | - Naveed Munir
- Department of Biochemistry, Government College University, Faisalabad, Pakistan
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13
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Kaye AD, Garcia AJ, Hall OM, Jeha GM, Cramer KD, Granier AL, Kallurkar A, Cornett EM, Urman RD. Update on the pharmacogenomics of pain management. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2019; 12:125-143. [PMID: 31308726 PMCID: PMC6613192 DOI: 10.2147/pgpm.s179152] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/09/2019] [Indexed: 12/30/2022]
Abstract
Pharmacogenomics is the study of genetic variants that impact drug effects through changes in a drug’s pharmacokinetics and pharmacodynamics. Pharmacogenomics is being integrated into clinical pain management practice because variants in individual genes can be predictive of how a patient may respond to a drug treatment. Pain is subjective and is considered challenging to treat. Furthermore, pain patients do not respond to treatments in the same way, which makes it hard to issue a consistent treatment regimen for all pain conditions. Pharmacogenomics would bring consistency to the subjective nature of pain and could revolutionize the field of pain management by providing personalized medical care tailored to each patient based on their gene variants. Additionally, pharmacogenomics offers a solution to the opioid crisis by identifying potentially opioid-vulnerable patients who could be recommended a nonopioid treatment for their pain condition. The integration of pharmacogenomics into clinical practice creates better and safer healthcare practices for patients. In this article, we provide a comprehensive history of pharmacogenomics and pain management, and focus on up to date information on the pharmacogenomics of pain management, describing genes involved in pain, genes that may reduce or guard against pain and discuss specific pain management drugs and their genetic correlations.
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Affiliation(s)
- Alan David Kaye
- Department of Anesthesiology, LSU Health Sciences Center, New Orleans, LA, USA
| | - Andrew Jesse Garcia
- Department of Anesthesiology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - O Morgan Hall
- Department of Anesthesiology, Louisiana State University School of Medicine, New Orleans, LA, USA
| | - George M Jeha
- Department of Anesthesiology, LSU Health Sciences Center New Orleans, New Orleans, LA, USA
| | - Kelsey D Cramer
- Department of Anesthesiology, LSU Health Sciences Center New Orleans, New Orleans, LA, USA
| | - Amanda L Granier
- Department of Anesthesiology, LSU Health Sciences Center New Orleans, New Orleans, LA, USA
| | - Anusha Kallurkar
- Department of Anesthesiology, LSU Health Shreveport, Shreveport, LA, USA
| | - Elyse M Cornett
- Department of Anesthesiology, LSU Health Shreveport, Shreveport, LA, USA
| | - Richard D Urman
- Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA
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Nutter SC, Gálvez‐Peralta M. Pharmacogenomics: From classroom to practice. Mol Genet Genomic Med 2018; 6:307-313. [PMID: 29852540 PMCID: PMC6014445 DOI: 10.1002/mgg3.417] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022] Open
Abstract
Perceptions and challenges connecting Pharmacogenomics taught in classrooms and translationing it to advance pharmacy practice rotations and healthcare settings and potential areas of development.
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Affiliation(s)
- Samantha C. Nutter
- Department of Pharmaceutical SciencesWest Virginia University School of PharmacyMorgantownWest Virginia
| | - Marina Gálvez‐Peralta
- Department of Pharmaceutical SciencesWest Virginia University School of PharmacyMorgantownWest Virginia
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Moyer AM, Caraballo PJ. The challenges of implementing pharmacogenomic testing in the clinic. Expert Rev Pharmacoecon Outcomes Res 2017; 17:567-577. [PMID: 28949250 DOI: 10.1080/14737167.2017.1385395] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Pharmacogenomic testing has the potential to greatly benefit patients by enabling personalization of medication management, ensuring better efficacy and decreasing the risk of side effects. However, to fully realize the potential of pharmacogenomic testing, there are several important issues that must be addressed. Areas covered: In this expert review we discuss current challenges impacting the implementation of pharmacogenomic testing in the clinical practice. We emphasize issues related to testing methods, reporting of the results, test selection, clinical interpretation of the results, cost-effectiveness, and the long-term use of pharmacogenomic results in clinical practice. We identify opportunities and future directions to facilitate clinical implementation. Expert commentary: Several key elements are necessary to optimally integrate pharmacogenomic testing into clinical practice. Collaborative efforts among laboratories are needed to improve standardization of testing and reporting of the results. Clinicians need educational opportunities to improve understanding of which test to order and how to interpret the results. The electronic health records and other clinical systems need to improve their storage of the pharmacogenomics test results and interoperability to facilitate the use of clinically actionable results to improve patient care.
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Affiliation(s)
- Ann M Moyer
- a Department of Laboratory Medicine and Pathology , Mayo Clinic , Rochester , MN , USA
| | - Pedro J Caraballo
- b Department of Medicine , Mayo Clinic , Rochester , MN , USA.,c Center for Translational Informatics and Knowledge Management, Mayo Clinic , Rochester , MN , USA
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16
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Cloete R, Akurugu WA, Werely CJ, van Helden PD, Christoffels A. Structural and functional effects of nucleotide variation on the human TB drug metabolizing enzyme arylamine N-acetyltransferase 1. J Mol Graph Model 2017. [PMID: 28628859 DOI: 10.1016/j.jmgm.2017.04.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human arylamine N-acetyltransferase 1 (NAT1) enzyme plays a vital role in determining the duration of action of amine-containing drugs such as para-aminobenzoic acid (PABA) by influencing the balance between detoxification and metabolic activation of these drugs. Recently, four novel single nucleotide polymorphisms (SNPs) were identified within a South African mixed ancestry population. Modeling the effects of these SNPs within the structural protein was done to assess possible structure and function changes in the enzyme. The use of molecular dynamics simulations and stability predictions indicated less thermodynamically stable protein structures containing E264K and V231G, while the N245I change showed a stabilizing effect. Coincidently the N245I change displayed a similar free energy landscape profile to the known R64W amino acid substitution (slow acetylator), while the R242M displayed a similar profile to the published variant, I263V (proposed fast acetylator), and the wild type protein structure. Similarly, principal component analysis indicated that two amino acid substitutions (E264K and V231G) occupied less conformational clusters of folded states as compared to the WT and were found to be destabilizing (may affect protein function). However, two of the four novel SNPs that result in amino acid changes: (V231G and N245I) were predicted by both SIFT and POLYPHEN-2 algorithms to affect NAT1 protein function, while two other SNPs that result in R242M and E264K substitutions showed contradictory results based on SIFT and POLYPHEN-2 analysis. In conclusion, the structural methods were able to verify that two non-synonymous substitutions (E264K and V231G) can destabilize the protein structure, and are in agreement with mCSM predictions, and should therefore be experimentally tested for NAT1 activity. These findings could inform a strategy of incorporating genotypic data (i.e., functional SNP alleles) with phenotypic information (slow or fast acetylator) to better prescribe effective treatment using drugs metabolized by NAT1.
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Affiliation(s)
- Ruben Cloete
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Bellville, Cape Town 7535, South Africa.
| | - Wisdom A Akurugu
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Bellville, Cape Town 7535, South Africa.
| | - Cedric J Werely
- SAMRC Centre for Molecular and Cellular Biology, and DST-NRF Centre of Excellence for Biomedical TB Research. Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town 8000, South Africa.
| | - Paul D van Helden
- SAMRC Centre for Molecular and Cellular Biology, and DST-NRF Centre of Excellence for Biomedical TB Research. Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town 8000, South Africa.
| | - Alan Christoffels
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Bellville, Cape Town 7535, South Africa.
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Keel BN, Nonneman DJ, Rohrer GA. A survey of single nucleotide polymorphisms identified from whole-genome sequencing and their functional effect in the porcine genome . Anim Genet 2017; 48:404-411. [PMID: 28485055 DOI: 10.1111/age.12557] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2017] [Indexed: 12/30/2022]
Abstract
Genetic variants detected from sequence have been used to successfully identify causal variants and map complex traits in several organisms. High and moderate impact variants, those expected to alter or disrupt the protein coded by a gene and those that regulate protein production, likely have a more significant effect on phenotypic variation than do other types of genetic variants. Hence, a comprehensive list of these functional variants would be of considerable interest in swine genomic studies, particularly those targeting fertility and production traits. Whole-genome sequence was obtained from 72 of the founders of an intensely phenotyped experimental swine herd at the U.S. Meat Animal Research Center (USMARC). These animals included all 24 of the founding boars (12 Duroc and 12 Landrace) and 48 Yorkshire-Landrace composite sows. Sequence reads were mapped to the Sscrofa10.2 genome build, resulting in a mean of 6.1 fold (×) coverage per genome. A total of 22 342 915 high confidence SNPs were identified from the sequenced genomes. These included 21 million previously reported SNPs and 79% of the 62 163 SNPs on the PorcineSNP60 BeadChip assay. Variation was detected in the coding sequence or untranslated regions (UTRs) of 87.8% of the genes in the porcine genome: loss-of-function variants were predicted in 504 genes, 10 202 genes contained nonsynonymous variants, 10 773 had variation in UTRs and 13 010 genes contained synonymous variants. Approximately 139 000 SNPs were classified as loss-of-function, nonsynonymous or regulatory, which suggests that over 99% of the variation detected in our pigs could potentially be ignored, allowing us to focus on a much smaller number of functional SNPs during future analyses.
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Affiliation(s)
- B N Keel
- USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - D J Nonneman
- USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - G A Rohrer
- USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE, 68933, USA
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Rogers Z, Hiruy H, Pasipanodya JG, Mbowane C, Adamson J, Ngotho L, Karim F, Jeena P, Bishai W, Gumbo T. The Non-Linear Child: Ontogeny, Isoniazid Concentration, and NAT2 Genotype Modulate Enzyme Reaction Kinetics and Metabolism. EBioMedicine 2016; 11:118-126. [PMID: 27528266 PMCID: PMC5049930 DOI: 10.1016/j.ebiom.2016.07.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 11/25/2022] Open
Abstract
N-acetyltransferase 2 (NAT2) catalyzes the acetylation of isoniazid to N-acetylisoniazid. NAT2 polymorphism explains 88% of isoniazid clearance variability in adults. We examined the effects of clinical and genetic factors on Michaelis-Menten reaction kinetic constants of maximum velocity (Vmax) and affinity (Km) in children 0–10 years old. We measured the rates of isoniazid elimination and N-acetylisoniazid production in the blood of 30 children. Since maturation effects could be non-linear, we utilized a pharmacometric approach and the artificial intelligence method, multivariate adaptive regression splines (MARS), to identify factors predicting NAT2 Vmax and Km by examining clinical, genetic, and laboratory factors in toto. Isoniazid concentration predicted both Vmax and Km and superseded the contribution of NAT2 genotype. Age non-linearly modified the NAT2 genotype contribution until maturation at ≥ 5.3 years. Thus, enzyme efficiency was constrained by substrate concentration, genes, and age. Since MARS output is in the form of basis functions and equations, it allows multiscale systems modeling from the level of cellular chemical reactions to whole body physiological parameters, by automatic selection of significant predictors by the algorithm. We identified the NAT2 Km and Vmax in children treated with isoniazid. Artificial intelligence (AI) algorithms were used to find predictors of Km and Vmax. Isoniazid concentration affected Vmax and Km, and superseded NAT2 genotype. Age non-linearly modified NAT2 genotype contribution until maturation at ≥ 5.3 years. AI output is in the form of equations that allow multiscale systems modeling.
The effects of maturation on drug metabolism have not been studied for the type phase II enzymes such as NAT2, which metabolizes the drug isoniazid. Genes have been found to control speed of isoniazid metabolism. Studies to characterize affinity and maximum velocity for isoniazid metabolism in people were last performed in two individuals' livers in the 1960s. We identified NAT2 affinity and maximum velocity in 30 tuberculosis children treated with isoniazid. Artificial intelligence methods found that metabolism was affected by the drug's concentration more than by genes, which were affected by age up to 5.3 years.
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Affiliation(s)
- Zoe Rogers
- KwaZulu-Natal Research Institute for TB and HIV, Durban 4001, South Africa
| | - Hiwot Hiruy
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Jotam G Pasipanodya
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX 75204, USA
| | - Chris Mbowane
- Dept of Pediatrics, Nelson Mandela School of Medicine, UKZN, Durban 4001, South Africa
| | - John Adamson
- KwaZulu-Natal Research Institute for TB and HIV, Durban 4001, South Africa
| | - Lihle Ngotho
- KwaZulu-Natal Research Institute for TB and HIV, Durban 4001, South Africa
| | - Farina Karim
- KwaZulu-Natal Research Institute for TB and HIV, Durban 4001, South Africa
| | - Prakash Jeena
- Dept of Pediatrics, Nelson Mandela School of Medicine, UKZN, Durban 4001, South Africa
| | - William Bishai
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX 75204, USA; Department of Medicine, University of Cape Town, Observatory, South Africa.
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Abstract
A young science serves its purpose if it leads not only to new knowledge, but to new insights and concepts. This article opens with examples to illustrate some former thinking that the introduction of pharmacogenetic has overcome. Pharmacogenetic case histories from discovery to the present illustrate the interlocking of observations, technical advances, and changing concepts. There are striking biological similarities between pharmacogenetics and those inborn factors that cause resistance to infectious disease: Both represent person-to-person variations that may help the survival of populations, one when facing massive toxic exposures, the other when facing plagues and epidemics. Thus pharmacogenetics represents a biologically necessary variability of the defenses against chemical intruders, and this includes drugs. While this variability is desirable, drug toxicity occurring on the basis of this variability must be avoided. The most successful defendants against toxicity due to polymorphic (ie, high incidence) variants should be the designers of new drugs. The only defender concerned with rare variants can be the attentive clinician.
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Affiliation(s)
- Werner Kalow
- Department of Pharmacology, Medical Sciences Building, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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20
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Mahajan R. Pharmacogenetics: A hope for difficult to treat chronic pain patients. Int J Appl Basic Med Res 2016; 6:77-8. [PMID: 27127733 PMCID: PMC4830159 DOI: 10.4103/2229-516x.179013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Rajiv Mahajan
- Department of Pharmacology, Adesh Institute of Medical Sciences and Research, Bathinda, Punjab, India
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21
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Abstract
After decades of discovery, inherited variations have been identified in approximately 20 genes that affect about 80 medications and are actionable in the clinic. And some somatically acquired genetic variants direct the choice of 'targeted' anticancer drugs for individual patients. Current efforts that focus on the processes required to appropriately act on pharmacogenomic variability in the clinic are moving away from discovery and towards implementation of an evidenced-based strategy for improving the use of medications, thereby providing a cornerstone for precision medicine.
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Daly AK. Pharmacogenetics of drug metabolizing enzymes in the United Kingdom population: review of current knowledge and comparison with selected European populations. Drug Metab Pers Ther 2015; 30:165-174. [PMID: 25803091 DOI: 10.1515/dmdi-2014-0034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/23/2015] [Indexed: 06/04/2023]
Abstract
Data on frequency of pharmacogenetic polymorphisms in the UK population are limited. However, availability of whole genome sequencing data on 94 UK controls of European ethnicity from the 1000 genomes project together with similar data on other populations provides a valuable new source of data in this area and allows direct comparison of allele frequencies with those for other European populations. The ethnic diversity of the UK population also needs to be considered, and 1000 genomes includes data on South Asians, the most common ethnic group in the UK after White Europeans. Allele frequencies for polymorphisms in genes relevant to phase I and phase II drug metabolism for UK, Finnish, Spanish and South Asian populations were obtained from the literature and 1000 genomes. Generally there was good agreement between the literature and 1000 genomes reports. CYP2D6*4, the most common CYP2D6 poor metabolizer allele among Europeans, appears more common in the UK than in Spain and Finland, whereas, as suggested previously, CYP2C19*2 and CYP2C9*2 appear more common in Finland and Spain, respectively, than in the UK. South Asians show low frequencies of CYP2C9*2 and CYP2C19*17 but higher frequencies of CYP2C19*2 compared with UK residents of European ethnicity. Though personalizing drug treatment on the basis of individual genotype rather than ethnicity may be more appropriate, differences in allele frequencies across continents should be considered when designing clinical trials of new drugs.
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23
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Fluegge KR, Roe BE. A comparative effectiveness analysis of treatment for latent tuberculosis infection using multilevel selection models. J Comp Eff Res 2015; 4:239-257. [PMID: 25965321 DOI: 10.2217/cer.15.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Nine months of isoniazid (9INH) is the gold standard for treatment of latent tuberculosis infection (LTBI). This paper compares the effectiveness of 9 months of isoniazid with 4 months of transitional rifampin (9H4R) to alternative therapies, including 9INH, 6 months of isoniazid (6INH) and 6 months of isoniazid with 4 months of transitional rifampin (6H4R), for treatment of LTBI. MATERIALS & METHODS Using an ethnically diverse clinic sample of 552 patients given treatment for LTBI with 9H4R, we use multilevel selection models to examine the adjusted comparative effectiveness of the regimens among ethnic groups that feature distinct genetic predispositions to side effects on INH. For unadjusted/absolute effectiveness, we simulated cost-effectiveness ratios for 4 months of rifampin (4RIF) and compared with bootstrapped confidence intervals for the alternative therapies. RESULTS There are variations in the comparative effectiveness across ethnic groups, with the most notable differences for 9H4R. For unadjusted/absolute effectiveness, 4RIF presents the greatest net benefit for US born black and African patients. For all other ethnic groups, 6H4R was the most effective. CONCLUSION Patient ethnicity affects tolerance to INH. 9H4R was the most effective LTBI treatment for all ethnicities. However, this result heavily depends on whether adjustments are made for self-selection.
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Affiliation(s)
- Kyle R Fluegge
- Department of Agricultural, Environmental & Development Economics, Ohio State University, 2120 Fyffe Road, Columbus, OH 43210, USA.,Division of Epidemiology, College of Public Health, Ohio State University, 2120 Fyffe Road, Columbus, OH 43210, USA.,Institute for Health & Environmental Research, Columbus, OH 43220, USA.,Department of Epidemiology & Biostatistics, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Brian E Roe
- Department of Agricultural, Environmental & Development Economics, Ohio State University, 2120 Fyffe Road, Columbus, OH 43210, USA
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Haghgoo SM, Allameh A, Mortaz E, Garssen J, Folkerts G, Barnes PJ, Adcock IM. Pharmacogenomics and targeted therapy of cancer: Focusing on non-small cell lung cancer. Eur J Pharmacol 2015; 754:82-91. [PMID: 25725115 DOI: 10.1016/j.ejphar.2015.02.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 02/11/2015] [Accepted: 02/17/2015] [Indexed: 12/20/2022]
Abstract
Recent studies have been established high degree of genetic diversity in solid organ tumors among individuals and even between individual tumor cells. This intratumor and intertumor genetic diversity results in a heterogeneous tumor with unique characteristics which potentially allows effective drug therapy. The goal of pharmacogenomics is to elucidate the genetic network(s) that underlie drug efficacy and drug resistance. Advances in targeted and personalized therapy play an increasingly important role in many common cancers, notably lung cancer, due to the high incidence, prevalence, mortality and the greater tendency towards drug resistance seen in these patients. Non-small cell lung cancer (NSCLC) is characterized by mutations in the epidermal growth factor receptor (EGFR) and or downstream kinase pathways. This has led to the development of highly selective monoclonal antibodies and EGFR tyrosine kinase inhibitors (EGFR-TKIs) to prevent cancer initiation, proliferation, differentiation, angiogenesis, survival, and invasion. However, resistance to many of these new treatments is induced and further pharmacogenomic analysis has revealed mutations associated with increased or reduced drug efficacy. Combinations of kinase inhibitors or potentially the targeting of cancer stem cells may further increase the success of pharmacogenomics in treating patients with lung cancer.
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Affiliation(s)
- Seyyed Mortaza Haghgoo
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abdolamir Allameh
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Esmaeil Mortaz
- Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, UK; Department of Immunology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Chronic Respiratory Diseases Research Center and National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
| | - Johan Garssen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands; Nutricia Research, Immunology, Utrecht, The Netherlands
| | - Gert Folkerts
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Peter J Barnes
- Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, UK
| | - Ian M Adcock
- Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, UK
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Sim E, Abuhammad A, Ryan A. Arylamine N-acetyltransferases: from drug metabolism and pharmacogenetics to drug discovery. Br J Pharmacol 2014; 171:2705-25. [PMID: 24467436 PMCID: PMC4158862 DOI: 10.1111/bph.12598] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 08/15/2013] [Accepted: 08/26/2013] [Indexed: 12/12/2022] Open
Abstract
Arylamine N-acetyltransferases (NATs) are polymorphic drug-metabolizing enzymes, acetylating arylamine carcinogens and drugs including hydralazine and sulphonamides. The slow NAT phenotype increases susceptibility to hydralazine and isoniazid toxicity and to occupational bladder cancer. The two polymorphic human NAT loci show linkage disequilibrium. All mammalian Nat genes have an intronless open reading frame and non-coding exons. The human gene products NAT1 and NAT2 have distinct substrate specificities: NAT2 acetylates hydralazine and human NAT1 acetylates p-aminosalicylate (p-AS) and the folate catabolite para-aminobenzoylglutamate (p-abaglu). Human NAT2 is mainly in liver and gut. Human NAT1 and its murine homologue are in many adult tissues and in early embryos. Human NAT1 is strongly expressed in oestrogen receptor-positive breast cancer and may contribute to folate and acetyl CoA homeostasis. NAT enzymes act through a catalytic triad of Cys, His and Asp with the architecture of the active site-modulating specificity. Polymorphisms may cause unfolded protein. The C-terminus helps bind acetyl CoA and differs among NATs including prokaryotic homologues. NAT in Salmonella typhimurium supports carcinogen activation and NAT in mycobacteria metabolizes isoniazid with polymorphism a minor factor in isoniazid resistance. Importantly, nat is in a gene cluster essential for Mycobacterium tuberculosis survival inside macrophages. NAT inhibitors are a starting point for novel anti-tuberculosis drugs. Human NAT1-specific inhibitors may act in biomarker detection in breast cancer and in cancer therapy. NAT inhibitors for co-administration with 5-aminosalicylate (5-AS) in inflammatory bowel disease has prompted ongoing investigations of azoreductases in gut bacteria which release 5-AS from prodrugs including balsalazide.
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Affiliation(s)
- E Sim
- Faculty of Science Engineering and Computing, Kingston University, Kingston, UK; Department of Pharmacology, Oxford University, Oxford, UK
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Fluegge KR. Assessing the impact of patient self-selection on the costs to treat latent tuberculosis infection (LTBI) with isoniazid and transitional rifampin. J Eval Clin Pract 2014; 20:685-91. [PMID: 25087583 DOI: 10.1111/jep.12204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/16/2014] [Indexed: 11/27/2022]
Abstract
RATIONALE, AIMS AND OBJECTIVES This article examines costs to treat latent tuberculosis infection (LTBI) in an urban clinic population and highlights the potential effectiveness of an alternative transitional treatment regimen. METHODS Patients who experienced side effects on the gold standard of 9 months of isoniazid (9INH) were either continued on isoniazid or transitioned to 4 months of rifampin (4RIF). I use multilevel Tobit models with selection to analyse whether transitioning to 4RIF is less costly than remaining on 9INH among patients experiencing side effects. RESULTS Results reveal that self-selection is present in this clinic data. Using an ordered probit parametric selection rule to account for selection, I find transitioning patients to 4RIF costs significantly less than continuing on 9INH. This result is especially sensitive to selection: not controlling for selection demonstrates that patients transitioning to 4RIF actually cost significantly more to treat. Post hoc analysis revealed that switching to 4RIF significantly reduced the dropout probability among these patients. CONCLUSION Future work should more carefully assess the clinical attributes, including effectiveness, of treatment with 9INH and transitional 4RIF as alternative treatment for LTBI.
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Affiliation(s)
- Kyle R Fluegge
- Department of Agricultural, Environmental, and Development Economics, Division of Epidemiology, College of Public Health, The Ohio State University, Columbus, OH, USA; Institute of Health and Environmental Research (IHER), Columbus, OH, USA
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Yarosh SL, Kokhtenko EV, Churnosov MI, Ataman AV, Solodilova MA, Polonikov AV. Synergism between the N-acetyltransferase 2 gene and oxidant exposure increases the risk of idiopathic male infertility. Reprod Biomed Online 2014; 29:362-9. [PMID: 24928356 DOI: 10.1016/j.rbmo.2014.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 04/24/2014] [Accepted: 04/29/2014] [Indexed: 12/14/2022]
Abstract
N-acetyltransferase (NAT2) is a phase-II xenobiotic-metabolizing enzyme participating in the detoxification of toxic arylamines, aromatic amines and hydrazines. The present study was designed to investigate whether two common single-nucleotide polymorphisms (SNP) of the NAT2 gene (481C>T, rs1799929; 590G>A, rs1799930) are associated with susceptibility to idiopathic male infertility and to assess if the risk is modified by oxidant and antioxidant exposures. A total 430 DNA samples (203 infertile patients and 227 fertile men) were genotyped for the polymorphisms by PCR and restriction fragment length polymorphism. No association was found between the NAT2 polymorphisms and idiopathic male infertility. However, gene-environment interaction analysis revealed that a low-acetylation genotype, 590GA, was significantly associated with increased disease risk in men who had environmental risk factors such as cigarette smoking (OR 1.71, 95% CI 1.02-2.87, P = 0.042), alcohol abuse (OR 2.14, 95% CI 1.08-4.27, P = 0.029) and low fruit/vegetable intake (OR 1.68, 95% CI 1.01-2.79, P = 0.04). This pilot study found, as far as is known for the first time, that the polymorphism 590G>A of NAT2 is a novel genetic marker for susceptibility to idiopathic male infertility, but the risk is potentiated by exposure to various environmental oxidants.
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Affiliation(s)
- Sergey L Yarosh
- Department of Biology, Medical Genetics and Ecology, Kursk State Medical University, Kursk, Russian Federation; Family Planning and Reproductive Health Clinic, Regional Perinatal Center, Kursk, Russian Federation
| | - Elena V Kokhtenko
- Department of Zoology and Theory of Evolution, Kursk State University, Kursk, Russian Federation
| | - Mikhail I Churnosov
- Department of Medical Biological Disciplines, Belgorod State National Research University, Belgorod, Russian Federation
| | | | - Maria A Solodilova
- Department of Biology, Medical Genetics and Ecology, Kursk State Medical University, Kursk, Russian Federation
| | - Alexey V Polonikov
- Department of Biology, Medical Genetics and Ecology, Kursk State Medical University, Kursk, Russian Federation.
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MOSTAFA H, SAAD M, EL-ATTAR A, AHMED G, BERRETTINI S, FORLI F, SICILIANO G, MANCUSO M. Mitochondrial DNA (mtDNA) haplotypes and dysfunctions in presbyacusis. ACTA OTORHINOLARYNGOLOGICA ITALICA : ORGANO UFFICIALE DELLA SOCIETA ITALIANA DI OTORINOLARINGOLOGIA E CHIRURGIA CERVICO-FACCIALE 2014; 34:54-61. [PMID: 24711684 PMCID: PMC3970225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 02/08/2013] [Indexed: 11/14/2022]
Abstract
The aim of this study was to investigate the presence of mitochondrial DNA (mtDNA) alterations and metabolic dysfunctions in patients with presbyacusis, and to discover correlations between presbyacusis and the degree of hearing loss and mitochondrial damage. Seventy patients with presbyacusis were examined, including 40 Egyptian patients and 30 Italian patients. Forty eight normal subjects were included as control group, including 24 Egyptians and 24 Italians. There was no common point mutation, and A1555G, A3243G, A7445G not were detected in any patients or controls. Haplogroup U was significantly common in patients in comparison to controls. Mutation of antioxidant genes (GSTT1, GSTM1) were significantly present in only Italian patients compared to Italian controls.
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Affiliation(s)
- H. MOSTAFA
- Audiology Unit, ENT Department, Faculty Of Medicine, Assiut University, Egypt;,Address for correspondence: Hossam Mostafa. Audiology Unit, ENT Department, Assiut University Hospital, 71517, Egypt. E-mail:
| | - M. SAAD
- Audiology Unit, ENT Department, Faculty Of Medicine, Assiut University, Egypt
| | - A. EL-ATTAR
- Audiology Unit, ENT Department, Faculty Of Medicine, Assiut University, Egypt
| | - G. AHMED
- Department of Genetics, Faculty of Agriculture, Assiut University, Egypt
| | - S. BERRETTINI
- Department of otolaryngology, Faculty of Medicine, University of Pisa, Italy
| | - F. FORLI
- Department of otolaryngology, Faculty of Medicine, University of Pisa, Italy
| | - G. SICILIANO
- Department of Neurosciences, Faculty of Medicine, University of Pisa, Italy
| | - M. MANCUSO
- Department of Neurosciences, Faculty of Medicine, University of Pisa, Italy
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Abstract
The sequencing of the entire human genome was completed in June 2000. The sequence, however, is only a starting point and gene-function is now of major interest. All this information shows that gene-based diagnostics can be helpful for treatment targeting and patient surveillance. High volume gene expression assays can optimize pharmaceutical therapies by targeting genome-based treatments to specific patient populations and providing methods to study genes involved with cancer growth patterns and tumor suppression. Molecular biology, so far, has elucidated many of the genetic mechanisms underlying heritable metabolic diseases, so that appropriate diagnostic assays will revolutionize molecular diagnostics in medicine and pharmaceuticals. One of the most promising new technologies designed to analyze large amounts of genomic information rapidly is the DNA chip.
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Affiliation(s)
- Roland Toder
- R. Toder Consulting, Oleweg 7, D-79279 Vorstetten, Germany.
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Rana SV, Sharma SK, Ola RP, Kamboj JK, Malik A, Morya RK, Sinha SK. N-acetyltransferase 2, cytochrome P4502E1 and glutathione S-transferase genotypes in antitubercular treatment-induced hepatotoxicity in North Indians. J Clin Pharm Ther 2013; 39:91-6. [PMID: 24188272 DOI: 10.1111/jcpt.12105] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 09/30/2013] [Indexed: 11/30/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Tuberculosis (TB) is a major cause of illness and death in developing countries. Hepatotoxicity is a serious side effect of antituberculosis treatment (ATT). NAT2, CYP2E1 and glutathione S-transferase (GST) gene polymorphisms may play an important role in ATT-induced hepatotoxicity. So, elucidating the genetics involved in anti-TB drug-induced hepatotoxicity in patients would be of utmost clinical significance. Therefore, the objective of the study was to elucidate the role of NAT2, CYP2E1 and GST gene polymorphisms in ATT-induced hepatotoxicity in North Indian patients. METHODS Three hundred patients with pulmonary and extra-pulmonary TB were enrolled. Total genomic DNA was isolated from each patient's peripheral lymphocytes using phenol-chloroform method, and genetic polymorphic analysis for N-acetyltransferase 2 (NAT2), cytochrome P4502E1 (CYP2E1) and GST was performed by polymerase chain reaction (PCR) with restriction fragment length polymorphism (RFLP). RESULTS AND DISCUSSION Of the 300 patients, 185 were males and 115 females. Among them, 33 males and 22 females developed ATT-induced hepatotoxicity. There were significant increases in alanine aminotransferase, aspartate aminotransferase and bilirubin levels in patients with ATT-induced hepatotoxicity at 1 month of treatment. NAT2 5/7 and 6/7 were significantly higher in hepatotoxicity patients as compared to the non-hepatotoxicity group. c1/c1 allele of CYP2E1 gene was lower (50·9%) in ATT-induced hepatotoxicity patients as compared to non-hepatotoxicity patients (61·2%), whereas c1/c2 and c2/c2 alleles were higher, but not statistically significant. GSTM1 was significantly higher in hepatotoxicity patients as compared to non-hepatotoxicity patients, whereas GSTT1 and GSTT1/M1 were lower, but not statistically significant. WHAT IS NEW AND CONCLUSION This study indicates that patients with slow-acetylator genotypes (NAT2 5/7, 6/7) and GSTM1 allele of GST enzyme were at higher risk of ATT-induced hepatotoxicity.
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Affiliation(s)
- S V Rana
- Department of Super Specialty Gastroenterology, Post Graduate Institute of Medical Education & Research, Chandigarh, India
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Stacey M, Thygesen P, Stanley L, Matas N, Risch A, Sim E. Arylarnine N-acetyltransferase as a potential biornarker in bladder cancer: fluorescent in situ hybridization and irnmunohistochernistry studies. Biomarkers 2013; 1:55-61. [PMID: 23888894 DOI: 10.3109/13547509609079347] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract Arylamine N-acetyltransferase isoenzymes NAT1 and NAT2 are encoded at two polymorphic loci on human chromosome 8p22. The two loci have previously been identified using chimeric Yeast Artificial Chromosome (YAC) clones encoding either NAT1 or NAT2 as probes for metaphase chromosomes using fluorescent in situ hybridization. The 8p22 region has been demonstrated to be deleted in highly invasive bladder tumours and since NAT isoenzymes participate in the metabolism of arylamine bladder carcinogens, it is important to determine whether NAT1 and NAT2 gene loci are included in the region of deletion. We describe here the application of a cosmid clone for NAT2 as a biomarker for Fluorescent In Situ Hybridization (FISH) on interphase nuclei of exfoliated bladder cells. We also describe a 70kb probe for NAT1 which is a candidate for a suitable biomarker for use in similar FISH studies. lmmunohistochemical staining of bladder tumour sections with a polyclonal anti-peptide antibody specific for the NATl isoenzyme as a biomarker for NAT1 protein expression is also shown.
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Affiliation(s)
- M Stacey
- the Department of Pharmacology, University of Oxford, Mansfieid Road, Oxford, OXI 3QT, UK
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32
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Li X, Lian FM, Guo D, Fan L, Tang J, Peng JB, Deng HW, Liu ZQ, Xiao XH, Wang YR, Qu KY, Deng S, Zhong Q, Sha YL, Zhu Y, Bai YJ, Chen XY, Zhou Q, Zhou HH, Tong XL, Zhang W. The rs1142345 in TPMT Affects the Therapeutic Effect of Traditional Hypoglycemic Herbs in Prediabetes. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2013; 2013:327629. [PMID: 23737827 PMCID: PMC3657408 DOI: 10.1155/2013/327629] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 03/25/2013] [Accepted: 03/25/2013] [Indexed: 01/26/2023]
Abstract
Therapeutic interventions in prediabetes are important in the primary prevention of type 2 diabetes (T2D) and its chronic complications. However, little is known about the pharmacogenetic effect of traditional herbs on prediabetes treatment. A total of 194 impaired glucose tolerance (IGT) subjects were treated with traditional hypoglycemic herbs (Tianqi Jiangtang) for 12 months in this study. DNA samples were genotyped for 184 mutations in 34 genes involved in drug metabolism or transportation. Multinomial logistic regression analysis indicated that rs1142345 (A > G) in the thiopurine S-methyltransferase (TPMT) gene was significantly associated with the hypoglycemic effect of the drug (P = 0.001, FDR P = 0.043). The "G" allele frequencies of rs1142345 in the healthy (subjects reverted from IGT to normal glucose tolerance), maintenance (subjects still had IGT), and deterioration (subjects progressed from IGT to T2D) groups were 0.094, 0.214, and 0.542, respectively. Binary logistic regression analysis indicated that rs1142345 was also significantly associated with the hypoglycemic effect of the drug between the healthy and maintenance groups (P = 0.027, OR = 4.828) and between the healthy and deterioration groups (P = 0.001, OR = 7.811). Therefore, rs1142345 was associated with the clinical effect of traditional hypoglycemic herbs. Results also suggested that TPMT was probably involved in the pharmacological mechanisms of T2D.
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Affiliation(s)
- Xi Li
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Feng-Mei Lian
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Dong Guo
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Lan Fan
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Jie Tang
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Jing-Bo Peng
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Hong-Wen Deng
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Zhao-Qian Liu
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Xin-Hua Xiao
- Department of Endocrinology, Peking Union Medical College Hospital, China Academy of Medical Sciences, Beijing 100730, China
| | - Yan-Rong Wang
- Department of Endocrinology, Peking University Third Hospital, Peking University, Beijing 100083, China
| | - Ke-Yi Qu
- Department of Endocrinology, Yiling Hospital, Yichang, Hubei 443100, China
| | - Sheng Deng
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
| | - Qi Zhong
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
| | - Yi-Ling Sha
- Department of Endocrinology, First People's Hospital of Hegang, Hegang, Heilongjiang 154100, China
| | - Yan Zhu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Yu-Jing Bai
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Xin-Yan Chen
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Qiang Zhou
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Hong-Hao Zhou
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
| | - Xiao-Lin Tong
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Wei Zhang
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, China
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Lin IS, Fan PL, Chen HI, Loh CH, Shih TS, Liou SH. Rapid and intermediate N-acetylators are less susceptible to oxidative damage among 4,4'-methylenebis(2-chloroaniline) (MBOCA)-exposed workers. Int J Hyg Environ Health 2013; 216:515-20. [PMID: 23491024 DOI: 10.1016/j.ijheh.2013.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 01/30/2013] [Accepted: 02/04/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVES In this study, we explored the association between a marker of oxidative stress, 8-hydroxydeoxyguanosine (8-OHdG), and genetic polymorphism of the carcinogen-metabolizing enzyme N-acetyltransferase 2 (NAT2) among 4,4'-methylenebis(2-chloroaniline) (MBOCA)-exposed workers. METHODS The study population was recruited from four MBOCA-producing factories, and included 57 MBOCA-exposed workers and 101 unexposed control workers. Personal characteristics were collected by questionnaire. Plasma 8-OHdG levels were measured by LC/MS/MS. NAT2 alleles were measured by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). RESULTS NAT2 polymorphism influenced the plasma 8-OHdG levels of MBOCA-exposed workers, but not of non-exposed workers. No difference between exposed and control groups was found for the crude 8-OHdG levels among rapid, intermediate, and slow acetylators. After adjusting for gender, age, smoking, and alcohol consumption habit, the 8-OHdG concentration in the MBOCA-exposed workers was 0.18pg/ml (95% CI -1.80 to -0.12) lower than the control group among rapid and intermediate acetylators. However, the difference between exposed and control groups was not significant for slow acetylators. CONCLUSION Gene-environment interactions could play a role in the carcinogenesis of occupational MBOCA exposure. We suggest that the impact of the NAT2 acetylator status is low, if at all, on the generation of the oxidative stress marker 8-OHdG in the investigated exposed group.
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Affiliation(s)
- I-Shen Lin
- Department of Family Medicine & Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Neihu, Taipei, Taiwan, ROC
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Djordjevic N, Carrillo JA, Ueda N, Gervasini G, Fukasawa T, Suda A, Jankovic S, Aklillu E. N-acetyltransferase-2 (NAT2) Gene Polymorphisms and Enzyme Activity in Serbs: Unprecedented High Prevalence of Rapid Acetylators in a White Population. J Clin Pharmacol 2013; 51:994-1003. [DOI: 10.1177/0091270010377630] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Wang X, Cui L, Zhou N, Zhu W, Wang R, Qian X, Xu Y. A highly selective and sensitive near-infrared fluorescence probe for arylamine N-acetyltransferase 2 in vitro and in vivo. Chem Sci 2013. [DOI: 10.1039/c3sc51079d] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Tilak AV, Iyer SN, Mukherjee MS, Singhal RS, Lele SS. Full-gene-sequencing analysis of N-acetyltransferase-2 in an adult Indian population. Genet Test Mol Biomarkers 2012; 17:188-94. [PMID: 23216273 DOI: 10.1089/gtmb.2012.0258] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
AIMS Drug-metabolizing enzymes play a major role in determining the outcome of drug therapy. N-acetyltransferase-2 (NAT2) is one of the main enzymes involved in metabolism of isoniazid used in treatment of tuberculosis (TB). Several variations in the NAT2 gene give rise to multiple haplotypes that phenotypically code for different acetylator status. The objective was to generate a more unambiguous picture of the NAT2 scenario in India as compared to that obtained from polymerase chain reaction-restriction fragment length polymorphism methods. METHODS Full-gene-sequencing analysis of NAT2 was carried out in 181 healthy Indian subjects from different regional groups. RESULTS A total of 33 diplotypes were recorded from six known single-nucleotide polymorphisms. The overall frequency of the slow acetylator haplotypes detected in this study was 65%, followed by 26% and 9% intermediate and rapid acetylators, respectively. Of the slow acetylator alleles, the NAT2*5B/*6A occurred in 25% of the study subjects. CONCLUSIONS The study indicates that the frequency of slow acetylator alleles is high in the adult Indian population. Since the prevalence of TB is high in this population, pharmacogenetic testing for NAT2 alleles may be advisable before start of therapy with isoniazid to prevent drug toxicity.
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Affiliation(s)
- Ashwini V Tilak
- Food Engineering and Technology Department (FETD), Institute of Chemical Technology (ICT), Matunga, Mumbai, India.
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Saghir SA, Khan SA, McCoy AT. Ontogeny of mammalian metabolizing enzymes in humans and animals used in toxicological studies. Crit Rev Toxicol 2012; 42:323-57. [PMID: 22512665 DOI: 10.3109/10408444.2012.674100] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
It is well recognized that expression of enzymes varies during development and growth. However, an in-depth review of this acquired knowledge is needed to translate the understanding of enzyme expression and activity into the prediction of change in effects (e.g. kinetics and toxicity) of xenobiotics with age. Age-related changes in metabolic capacity are critical for understanding and predicting the potential differences resulting from exposure. Such information may be especially useful in the evaluation of the risk of exposure to very low (µg/kg/day or ng/kg/day) levels of environmental chemicals. This review is to better understand the ontogeny of metabolizing enzymes in converting chemicals to either less-toxic metabolite(s) or more toxic products (e.g. reactive intermediate[s]) during stages before birth and during early development (neonate/infant/child). In this review, we evaluated the ontogeny of major "phase I" and "phase II" metabolizing enzymes in humans and commonly used experimental animals (e.g. mouse, rat, and others) in order to fill the information gap.
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Affiliation(s)
- Shakil Ahmed Saghir
- Toxicology & Environmental Research & Consulting, The Dow Chemical Company, Midland, Michigan, USA.
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Abstract
Clinical genetic testing has grown substantially over the past 30 years as the causative mutations for Mendelian diseases have been identified, particularly aided in part by the recent advances in molecular-based technologies. Importantly, the adoption of new tests and testing strategies (e.g., diagnostic confirmation, prenatal testing, and population-based carrier screening) has often been met with caution and careful consideration before clinical implementation, which facilitates the appropriate use of new genetic tests. Although the field of pharmacogenetics was established in the 1950s, clinical testing for constitutional pharmacogenetic variants implicated in interindividual drug response variability has only recently become available to help clinicians guide pharmacotherapy, in part due to US Food and Drug Administration-mediated product insert revisions that include pharmacogenetic information for selected drugs. However, despite pharmacogenetic associations with adverse outcomes, physician uptake of clinical pharmacogenetic testing has been slow. Compared with testing for Mendelian diseases, pharmacogenetic testing for certain indications can have a lower positive predictive value, which is one reason for underutilization. A number of other barriers remain with implementing clinical pharmacogenetics, including clinical utility, professional education, and regulatory and reimbursement issues, among others. This review presents some of the current opportunities and challenges with implementing clinical pharmacogenetic testing.
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Terai T, Kikuchi K, Urano Y, Kojima H, Nagano T. A long-lived luminescent probe to sensitively detect arylamine N-acetyltransferase (NAT) activity of cells. Chem Commun (Camb) 2012; 48:2234-6. [DOI: 10.1039/c2cc17622j] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Arylamine N-Acetyltransferases – from Drug Metabolism and Pharmacogenetics to Identification of Novel Targets for Pharmacological Intervention. CURRENT CONCEPTS IN DRUG METABOLISM AND TOXICOLOGY 2012; 63:169-205. [DOI: 10.1016/b978-0-12-398339-8.00005-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Semiz S, Dujic T, Ostanek B, Velija-Asimi Z, Prnjavorac B, Bego T, Malenica M, Mlinar B, Heljic B, Marc J, Causevic A. Association of NAT2 polymorphisms with type 2 diabetes in a population from Bosnia and Herzegovina. Arch Med Res 2011; 42:311-7. [PMID: 21820610 DOI: 10.1016/j.arcmed.2011.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 06/09/2011] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND AIMS N-acetyltransferase 2 (NAT2) is a drug-metabolizing enzyme, which is genetically variable in human populations. Polymorphisms in the NAT2 gene have been associated with drug efficacy and toxicity as well as disease susceptibility. Recently, an association of NAT2 gene variation with risk of type 2 diabetes mellitus (T2DM) has been suggested. This is the first study performed in a population from Bosnia and Herzegovina (BH) in which the frequency of two common NAT2 polymorphisms, 341T>C (NAT2*5) and 590G>A (NAT2*6) was determined in diabetic patients. METHODS The frequency of the NAT2*5 (341T>C) and NAT2*6 (590G>A) polymorphisms was analyzed by employing TaqMan SNP Genotyping Assays (Applied Biosystems) in a group of 63 patients with T2DM and 79 nondiabetic subjects. RESULTS Our data demonstrated that the frequencies of NAT2*5 (341T>C) and NAT2*6 (590G>A) polymorphisms in BH population were in line with the Caucasians genotype data. The NAT2*5 and NAT2*6 alleles were in high linkage disequilibrium (D' = 0.969). Strinkingly, there was a significant difference in genotype frequencies for NAT2*5 (p <0.05) and NAT2*6 (p <0.001) polymorphisms between diabetic and nondiabetic subjects. NAT2*5 polymorphism was associated with 2.4-fold increased risk for developing T2DM (adjusted OR = 2.40, 95% CI = 1.10-5.25, p = 0.028). On the contrary, NAT2*6 variant significantly decreased by 5-fold susceptibility to the disease (adjusted OR = 0.20, 95% CI = 0.09-0.43, p <0.001). CONCLUSIONS Our data demonstrated that NAT2 genetic variation appeared to be an important risk factor in development of T2DM.
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Affiliation(s)
- Sabina Semiz
- Department of Biochemistry and Clinical Analysis, Faculty of Pharmacy, University of Sarajevo, Bosnia and Herzegovina.
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Zheng Y, Li Y, Teng Y, Zhang Z, Cao X. Association of NAT2 phenotype with risk of head and neck carcinoma: A meta-analysis. Oncol Lett 2011; 3:429-434. [PMID: 22740926 DOI: 10.3892/ol.2011.493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/17/2011] [Indexed: 12/23/2022] Open
Abstract
N-acetyltransferase 2 (NAT2) is a key enzyme involved in the metabolism of xenobiotics and plays a significant role in the detoxification of numerous potential carcinogens. According to its acetylation status, NAT2 acetylator may be classified into two phenotypes, rapid and slow. Numerous studies have demonstrated that the polymorphisms of NAT2 were correlated with individual susceptibility to several malignant neoplasms, including head and neck carcinomas (HNC). However, the associations between the acetylator phenotypes and HNC risk in each study were not entirely consistent. To assess these associations more comprehensively, we performed a meta-analysis. In this meta-analysis, 16 eligible studies including 2,965 cases with HNC and 3,919 controls were identified by searching the databases of PubMed, Medline and the ISI Web of Knowledge. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were used to evaluate the association. No significant associations between the rapid acetylator phenotype in NAT2 and HNC risk were found either in the overall analysis (OR=0.98; 95% CI 0.83, 1.15; I(2)=57%; P(heterogeneity)=0.003) or in the subgroup analysis by ethnicity (for the Caucasian population, OR=1.03, 95% CI 0.85, 1.24, I(2)=63%, P(heterogeneity)=0.002; for other mixed populations, OR=0.78, 95% CI=0.61, 1.00, I(2)=0%, P(heterogeneity)=0.47). In conclusion, this meta-analysis suggested that there is no association between the NAT2 phenotype and the risk of HNC.
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Affiliation(s)
- Youyang Zheng
- Department of Stomatology, The Second Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou 310009
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Hein DW, Doll MA. Accuracy of various human NAT2 SNP genotyping panels to infer rapid, intermediate and slow acetylator phenotypes. Pharmacogenomics 2011; 13:31-41. [PMID: 22092036 DOI: 10.2217/pgs.11.122] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Humans exhibit genetic polymorphism in NAT2 resulting in rapid, intermediate and slow acetylator phenotypes. Over 65 NAT2 variants possessing one or more SNPs in the 870-bp NAT2 coding region have been reported. The seven most frequent SNPs are rs1801279 (191G>A), rs1041983 (282C>T), rs1801280 (341T>C), rs1799929 (481C>T), rs1799930 (590G>A), rs1208 (803A>G) and rs1799931 (857G>A). The majority of studies investigate the NAT2 genotype assay for three SNPs: 481C>T, 590G>A and 857G>A. A tag-SNP (rs1495741) recently identified in a genome-wide association study has also been proposed as a biomarker for the NAT2 phenotype. MATERIALS & METHODS Sulfamethazine N-acetyltransferase catalytic activities were measured in cryopreserved human hepatocytes from a convenience sample of individuals in the USA with an ethnic frequency similar to the 2010 US population census. These activities were segregated by the tag-SNP rs1495741 and each of the seven SNPs described above. We assessed the accuracy of the tag-SNP and various two-, three-, four- and seven-SNP genotyping panels for their ability to accurately infer NAT2 phenotype. RESULTS The accuracy of the various NAT2 SNP genotype panels to infer NAT2 phenotype were as follows: seven-SNP: 98.4%; tag-SNP: 77.7%; two-SNP: 96.1%; three-SNP: 92.2%; and four-SNP: 98.4%. CONCLUSION A NAT2 four-SNP genotype panel of rs1801279 (191G>A), rs1801280 (341T>C), rs1799930 (590G>A) and rs1799931 (857G>A) infers NAT2 acetylator phenotype with high accuracy, and is recommended over the tag-, two-, three- and (for economy of scale) the seven-SNP genotyping panels, particularly in populations of non-European ancestry.
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Affiliation(s)
- David W Hein
- Department of Pharmacology & Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40202-1617, USA
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Mukherjee S, Bhowmik AD, Roychoudhury P, Mukhopadhyay K, Ray JG, Chaudhuri K. Association of XRCC1, XRCC3, and NAT2 polymorphisms with the risk of oral submucous fibrosis among eastern Indian population. J Oral Pathol Med 2011; 41:292-302. [PMID: 22092501 DOI: 10.1111/j.1600-0714.2011.01097.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Arecanut and smokeless tobacco usage is a major cause for oral submucous fibrosis (OSF) and its subsequent development to oral squamous cell carcinoma in South-east Asian population. Polymorphisms at N-acetyltransferase 2 locus, coding for an enzyme catalyzing acetylation of aromatic amines, might cause DNA adduct formation because of improper acetylation of these polyaromatic hydrocarbons. DNA repair enzymes remove these adduct to prevent malignancy. METHODS In this hospital-based study, 100 controls and 88 OSF patients were genotyped at four polymorphic sites on NAT2 481 (C > T; silent), 590 (G > A; Arg197 > Gln), 803 (A > G; Lys268 > Arg), 857 (G > A; Gly286 > Glu) and two on XRCC1 18067 (C > T Arg 194 > Trp), 28152 (G > A Arg 399 > Gln), and one of XRCC3 26304 (C > T Thr 241 > Met) loci by PCR-RFLP to determine the risk of the disease. RESULTS Heterozygous XRCC3 codon 241 [OR 2.07 (1.05-4.06)], homozygous variant of NAT C481T [OR 2.81 (1.09-7.21)], and both heterozygous and homozygous variants of NAT codon 268 and 286 [OR 2.31 (1.20-4.45) and 4.98 (1.87-13.14), and 6.12 (2.75-13.62) and 2.65 (1.04-6.72)] individually influenced susceptibility to OSF in the population. CONCLUSION Gene-gene interaction analysis by multifactor dimensionality reduction (MDR) revealed that XRCC3 Thr 241 Met had the largest univariate effect followed by XRCC3 Thr 241 Met - NAT2 A857G in men that presents a highly synergistic interaction as one of the potential combinations of single nucleotide polymorphisms (SNPs) to increase the risk of OSF in men if exposed to arecanut or smokeless tobacco usage. These observations can speculate the impact of the studied SNPs on the etiology of OSF.
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Affiliation(s)
- Sanjit Mukherjee
- Molecular & Human Genetics Division, Indian Institute of Chemical Biology (A Unit of CSIR), Kolkata, India
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Pinto N, Dolan ME. Clinically relevant genetic variations in drug metabolizing enzymes. Curr Drug Metab 2011; 12:487-97. [PMID: 21453273 DOI: 10.2174/138920011795495321] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 03/14/2011] [Indexed: 01/11/2023]
Abstract
In the field of pharmacogenetics, we currently have a few markers to guide physicians as to the best course of therapy for patients. For the most part, these genetic variants are within a drug metabolizing enzyme that has a large effect on the degree or rate at which a drug is converted to its metabolites. For many drugs, response and toxicity are multi-genic traits and understanding relationships between a patient's genetic variation in drug metabolizing enzymes and the efficacy and/or toxicity of a medication offers the potential to optimize therapies. This review will focus on variants in drug metabolizing enzymes with predictable and relatively large impacts on drug efficacy and/or toxicity; some of these drug/gene variant pairs have impacted drug labels by the United States Food and Drug Administration. The challenges in identifying genetic markers and implementing clinical changes based on known markers will be discussed. In addition, the impact of next generation sequencing in identifying rare variants will be addressed.
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Affiliation(s)
- Navin Pinto
- Section of Hematology/Oncology, Department of Pediatrics, Comprehensive Cancer Center, The University of Chicago, Illinois, USA.
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Turesky RJ, Le Marchand L. Metabolism and biomarkers of heterocyclic aromatic amines in molecular epidemiology studies: lessons learned from aromatic amines. Chem Res Toxicol 2011; 24:1169-214. [PMID: 21688801 PMCID: PMC3156293 DOI: 10.1021/tx200135s] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct, and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels, and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs, and thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and emerging biomarkers of HAAs that may be implemented in molecular epidemiology studies are discussed.
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Affiliation(s)
- Robert J Turesky
- Division of Environmental Health Sciences, Wadsworth Center , Albany, New York 12201, United States.
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McQueen CA. Measuring the activity of arylamine N-acetyltransferase (NAT). ACTA ACUST UNITED AC 2011; Chapter 4:Unit4.6. [PMID: 20945298 DOI: 10.1002/0471140856.tx0406s10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This unit describes methods for measuring the activity of arylamine N-acetyltransferases (NAT). Genetic polymorphisms in NAT 1 and NAT 2 have been associated with susceptibility to aromatic amines carcinogens and effects of therapeutic drugs. Evaluation of the activities associated with substrates of NATs is helpful in elucidating the contribution of these enzymes to the pharmacologic and toxicologic effects of arylamines and hydrazines.
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Bose PD, Sarma MP, Medhi S, Das BC, Husain SA, Kar P. Role of polymorphic N-acetyl transferase2 and cytochrome P4502E1 gene in antituberculosis treatment-induced hepatitis. J Gastroenterol Hepatol 2011; 26:312-8. [PMID: 21261721 DOI: 10.1111/j.1440-1746.2010.06355.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIM Antituberculosis drugs, isoniazid and rifampicin, in combination, are known to develop drug-induced hepatotoxicity (DIH). A higher risk of DIH during antituberculosis treatment (ATT) has been reported in the Indian subcontinent compared to its Western counterparts. The role of genetic factors in a higher incidence of ATT hepatotoxicity in the Indian population is still unclear. The present study was aimed at investigating the role of the N-acetyltransferase2 (NAT2) and cytochrome P4502E1 (CYP2E1) gene polymorphisms in ATT hepatotoxicity. METHODS The study population included 218 pulmonary tuberculosis patients who were started on ATT and followed up for the occurrence of ATT-induced hepatitis. The genetic polymorphisms of the NAT2 and CYP2E1 genes were studied by polymerase chain reaction-restriction fragment length polymorphism. RESULTS The occurrence of DIH was 18.8% (41/218). There was a higher prevalence of NAT2 slow-acetylator genotypes in DIH (70.73%) compared to non-DIH (44.63%; P < 0.05). The frequency of the NAT2*5/*7 and NAT2*6/*7 genotypes was significantly higher in DIH than non-DIH (19.51% vs 6.78%, and 19.51% vs 5.08%). No association of the CYP2E1 RsaI polymorphism could be demonstrated with DIH. However, the DraI C/D genotype of the CYP2E1 gene was mostly prevalent in DIH (85.37%), compared to non-DIH (64.41%) (P < 0.05). Slow-acetylator status and the CYP2E1 C/D or C/C genotype together showed a higher frequency in DIH (65.85%) compared to non-DIH (28.81%) (P < 0.0001). CONCLUSION The study demonstrates for the first time a possible association between the DraI polymorphism of the CYP2E1 gene and the risk of ATT hepatotoxicity. The genotyping of the NAT2 and CYP2E1 genes could possibly identify the groups at highest risk of developing ATT-induced hepatitis prior to medication.
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Affiliation(s)
- Purabi Deka Bose
- Department of Medicine, Maulana Azad Medical College, New Delhi, India
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Pavanello S. Metabolic and DNA Repair Variations in Susceptibility to Genotoxins. Polycycl Aromat Compd 2010. [DOI: 10.1080/10406630308061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Sofia Pavanello
- a Section of Occupational Health, Department of Environmental Medicine and Public Health , University of Padova , Padova , Italy
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Antioxidant enzymes, presbycusis, and ethnic variability. Otolaryngol Head Neck Surg 2010; 143:263-8. [PMID: 20647132 DOI: 10.1016/j.otohns.2010.03.024] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 03/15/2010] [Accepted: 03/23/2010] [Indexed: 01/12/2023]
Abstract
OBJECTIVE A proposed mechanism for presbycusis is a significant increase in oxidative stress in the cochlea. The enzymes glutathione S-transferase (GST) and N-acetyltransferase (NAT) are two classes of antioxidant enzymes active in the cochlea. In this work, we sought to investigate the association of different polymorphisms of GSTM1, GSTT1, and NAT2 and presbycusis and analyze whether ethnicity has an effect in the genotype-phenotype associations. STUDY DESIGN Case-control study of 134 DNA samples. SETTING University-based tertiary care center. SUBJECTS AND METHODS Clinical, audiometric, and DNA testing of 55 adults with presbycusis and 79 control patients with normal hearing. RESULTS The GSTM1 null genotype was present in 77 percent of white Hispanics and 51 percent of white non-Hispanics (Fisher's exact test, 2-tail, P = 0.0262). The GSTT1 null genotype was present in 34 percent of control patients and in 60 percent of white presbycusis subjects (P = 0.0067, odds ratio [OR] = 2.843, 95% confidence interval [95% CI] = 1.379-5.860). The GSTM1 null genotype was more frequent in presbycusis subjects, i.e., 48 percent of control patients and 69 percent of white subjects carried this deletion (P = 0.0198, OR = 2.43, 95% CI = 1.163-5.067). The NAT2*6A mutant genotype was more frequent among subjects with presbycusis (60%) than in control patients (34%; P = 0.0086, OR = 2.88, 95% CI = 1.355-6.141). CONCLUSION We showed an increased risk of presbycusis among white subjects carrying the GSTM1 and the GSTT1 null genotype and the NAT*6A mutant allele. Subjects with the GSTT1 null genotypes are almost three times more likely to develop presbycusis than those with the wild type. The GSTM1 null genotype was more prevalent in white Hispanics than in white non-Hispanics, but the GSTT1 and NAT2 polymorphisms were equally represented in the two groups.
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