1
|
Langlois AW, Chenoweth MJ, Twesigomwe D, Scantamburlo G, Whirl-Carrillo M, Sangkuhl K, Klein TE, Nofziger C, Tyndale RF, Gaedigk A. PharmVar GeneFocus: CYP2A6. Clin Pharmacol Ther 2024; 116:948-962. [PMID: 39051767 PMCID: PMC11452280 DOI: 10.1002/cpt.3387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024]
Abstract
The Pharmacogene Variation Consortium (PharmVar) provides nomenclature for the human CYP2A gene locus containing the highly polymorphic CYP2A6 gene. CYP2A6 plays a role in the metabolism of nicotine and various drugs. Thus, genetic variation can substantially contribute to the function of this enzyme and associated efficacy and safety. This GeneFocus provides an overview of the clinical significance of CYP2A6, including its genetic variation and function. We also highlight and discuss caveats in the identification and characterization of allelic variation of this complex pharmacogene, a prerequisite for accurate genotype determination and prediction of phenotype status.
Collapse
Affiliation(s)
- Alec W.R. Langlois
- Department of Pharmacology & Toxicology, University of Toronto; 1 King’s College Circle, Toronto, ON, M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health 100 Stokes Street, Toronto, ON, M6J 1H4, Canada
| | - Meghan J. Chenoweth
- Department of Pharmacology & Toxicology, University of Toronto; 1 King’s College Circle, Toronto, ON, M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health 100 Stokes Street, Toronto, ON, M6J 1H4, Canada
- Department of Psychiatry, University of Toronto; 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - David Twesigomwe
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | | | - Katrin Sangkuhl
- Department of Biomedical Data Science, Stanford University, Stanford, California, USA
| | - Teri E. Klein
- Department of Biomedical Data Science, Stanford University, Stanford, California, USA
- Departments of Medicine (BMIR) and Genetics, Stanford University, Stanford, California, USA
| | | | - Rachel F. Tyndale
- Department of Pharmacology & Toxicology, University of Toronto; 1 King’s College Circle, Toronto, ON, M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health 100 Stokes Street, Toronto, ON, M6J 1H4, Canada
- Department of Psychiatry, University of Toronto; 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children’s Mercy Research Institute (CMRI), Kansas City, Missouri, USA and School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
| |
Collapse
|
2
|
Takeji S, Okada M, Hayashi S, Kanamaru K, Uno Y, Imaishi H, Uno T. Metabolism of testosterone and progesterone by cytochrome P450 2C19 allelic variants. Biopharm Drug Dispos 2023; 44:420-430. [PMID: 37815926 DOI: 10.1002/bdd.2378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 08/29/2023] [Accepted: 09/19/2023] [Indexed: 10/12/2023]
Abstract
CYP2C19 is a member of the human microsomal cytochrome P450 (CYP). Significant variation in CYP2C19 levels and activity can be attributed to polymorphisms in this gene. Wildtype CYP2C19 and 13 mutants (CYP2C19.1B, CYP2C19.5A, CYP2C19.5B, CYP2C19.6, CYP2C19.8, CYP2C19.9, CYP2C19.10, CYP2C19.11, CYP2C19.13, CYP2C19.16, CYP2C19.19, CYP2C19.23, CYP2C19.30, and CYP2C19.33) were coexpressed with NADPH-cytochrome P450 reductase in Escherichia coli. Hydroxylase activity toward testosterone and progesterone was also examined. Ten CYP2C19 variants showed Soret peaks (450 nm) typical of P450 in the reduced CO-difference spectra. CYP2C19.11 and CYP2C19.23 showed higher testosterone 11α, 16α-/17- and progesterone 6β-,21-,16α-/17α-hydroxylase activities than CYP2C19.1B. CYP2C19.6, CYP2C19.16, CYP2C19.19, and CYP2C19.30 showed lower activity than CYP2C19.1B. CYP2C19.9, CYP2C19.10. CYP2C19.13, and CYP2C19.33 showed different hydroxylation activities than CYP2C19.1B. These results indicated that CYP2C19 variants have very different substrate specificities for testosterone and progesterone.
Collapse
Affiliation(s)
- Shiori Takeji
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Mai Okada
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Shu Hayashi
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Kengo Kanamaru
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Yuichi Uno
- Department of Plant Resource Science, Faculty of Agriculture, Kobe University, Kobe, Japan
| | - Hiromasa Imaishi
- Functional Analysis of Environmental Genes, Research Center for Environmental, Genomics, Kobe University, Kobe, Japan
| | - Tomohide Uno
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| |
Collapse
|
3
|
Perez-Paramo YX, Watson CJ, Chen G, Thomas CE, Adams-Haduch J, Wang R, Khor CC, Koh WP, Nelson HH, Yuan JM, Lazarus P. Impact of Genetic Variants in the Nicotine Metabolism Pathway on Nicotine Metabolite Levels in Smokers. Cancer Epidemiol Biomarkers Prev 2023; 32:54-65. [PMID: 36252563 PMCID: PMC9827107 DOI: 10.1158/1055-9965.epi-22-0868] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/14/2022] [Accepted: 10/11/2022] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Nicotine metabolism is a major factor in nicotine dependence, with approximately 70% to 80% of nicotine metabolized to cotinine in Caucasians. Cotinine formation is catalyzed primarily by CYP2A6, which also converts cotinine to trans-3'-hydroxycotinine (3HC). The goal of the present study was to examine the effects of CYP2A6 deficiency on nicotine metabolism profiles in vivo and the importance of genetic variants in nicotine-metabolizing enzyme genes on urinary nicotine metabolites levels. METHODS Urine samples from 722 smokers who participated in the Singapore Chinese Health Study were analyzed using UPLC-MS/MS to detect nicotine and eight of its urinary metabolites, and a total of 58 variants in 12 genes involved in nicotine metabolism were investigated in 475 of these subjects with informative genotyping data. RESULTS Urine samples stratified by the ratio of 3HC/cotinine exhibited a 7-fold increase in nicotine-N'-oxide, a 6-fold increase in nicotine-Glucuronide (Gluc), and a 5-fold decrease in 3HC-Gluc when comparing the lower versus upper 3HC/cotinine ventiles. Significant (P < 0.0001) associations were observed between functional metabolizing enzyme genotypes and levels of various urinary nicotine metabolites, including CYP2A6 genotype and levels of nicotine, nicotine-Gluc, nicotine-N'-oxide and 3HC, UGT2B10 genotype and levels of cotinine, nicotine-Gluc and cotinine-Gluc, UGT2B17 genotype and levels of 3HC-Gluc, FMO3 genotype and levels of nicotine-N'-oxide, and CYP2B6 genotype and levels of nicotine-N'-oxide and 4-hydroxy-4-(3-pyridyl)-butanoic acid. CONCLUSIONS These data suggest that several pathways are important in nicotine metabolism. IMPACT Genotype differences in several nicotine-metabolizing enzyme pathways may potentially lead to differences in nicotine dependence and smoking behavior and cessation.
Collapse
Affiliation(s)
- Yadira X. Perez-Paramo
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Christy J.W. Watson
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Gang Chen
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Claire E. Thomas
- Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jennifer Adams-Haduch
- Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Renwei Wang
- Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Chiea Chuen Khor
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Eye Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Woon-Puay Koh
- Health Services and Systems Research, Duke-NUS Medical School Singapore, Singapore, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Heather H. Nelson
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.,Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota
| | - Jian-Min Yuan
- Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania.,Corresponding Authors: Philip Lazarus, College of Pharmacy and Pharmaceutical Sciences, Washington State University, PBS building, Room 431, Spokane, Washington, 99210-1495. E-mail: ; and Jian-Min Yuan, Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, 5150 Centre Avenue, Pittsburgh, Pennsylvania, 15232. E-mail:
| | - Philip Lazarus
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.,Corresponding Authors: Philip Lazarus, College of Pharmacy and Pharmaceutical Sciences, Washington State University, PBS building, Room 431, Spokane, Washington, 99210-1495. E-mail: ; and Jian-Min Yuan, Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, 5150 Centre Avenue, Pittsburgh, Pennsylvania, 15232. E-mail:
| |
Collapse
|
4
|
Kolli AR, Calvino-Martin F, Kuczaj AK, Wong ET, Titz B, Xiang Y, Lebrun S, Schlage WK, Vanscheeuwijck P, Hoeng J. Deconvolution of Systemic Pharmacokinetics Predicts Inhaled Aerosol Dosimetry of Nicotine. Eur J Pharm Sci 2023; 180:106321. [PMID: 36336278 DOI: 10.1016/j.ejps.2022.106321] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 10/21/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022]
Abstract
Absorption of inhaled compounds can occur from multiple sites based on upper and lower respiratory tract deposition, and clearance mechanisms leading to differential local and systemic pharmacokinetics. Deriving inhaled aerosol dosimetry and local tissue concentrations for nose-only exposure in rodents and inhaled products in humans is challenging. In this study we use inhaled nicotine as an example to identify regional respiratory tract deposition, absorption fractions, and their contribution toward systemic pharmacokinetics in rodents and humans. A physiologically based pharmacokinetic (PBPK) model was constructed to describe the disposition of nicotine and its major metabolite, cotinine. The model description for the lungs was simplified to include an upper respiratory tract region with active mucociliary clearance and a lower respiratory tract region. The PBPK model parameters such as rate of oral absorption, metabolism and clearance were fitted to the published nicotine and cotinine plasma concentrations post systemic administration and oral dosing. The fractional deposition of inhaled aerosol in the upper and lower respiratory tract regions was estimated by fitting the plasma concentrations. The model predicted upper respiratory tract deposition was 63.9% for nose-only exposure to nicotine containing nebulized aqueous aerosol in rats and 60.2% for orally inhaled electronic vapor product in humans. A marked absorption of nicotine from the upper respiratory tract and the gastrointestinal tract for inhaled aqueous aerosol contributed to the differential systemic pharmacokinetics in rats and humans. The PBPK model derived dosimetry shows that the current aerosol dosimetry models with their posteriori application using independent aerosol physicochemical characterization to predict aerosol deposition are insufficient and will need to consider complex interplay of inhaled aerosol evolutionary process. While the study highlights the needs for future research, it provides a preliminary framework for interpreting pharmacokinetics of inhaled aerosols to facilitate the analysis of in vivo exposure-responses for pharmacological and toxicological assessments.
Collapse
Affiliation(s)
- Aditya R Kolli
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland.
| | | | - Arkadiusz K Kuczaj
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Ee Tsin Wong
- Philip Morris International Research Laboratories Pte Ltd, 50 Science Park Road, The Kendall #02-07 Science Park II, 117406, Singapore
| | - Bjoern Titz
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Yang Xiang
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Stefan Lebrun
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Walter K Schlage
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland; Biology consultant, Max-Baermann-Str. 21, D-51429 Bergisch Gladbach, Germany
| | | | - Julia Hoeng
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| |
Collapse
|
5
|
Öner Ç, Soyergin D, Özyurt A, Çolak E. 4-Hydroxycoumarin Effects on Both Cellular and Genetic Characteristics of Hepatocellular Carcinoma Cells. CYTOL GENET+ 2022. [DOI: 10.3103/s0095452722030094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
6
|
Yadav VK, Katiyar T, Ruwali M, Yadav S, Singh S, Hadi R, Bhatt MLB, Parmar D. Polymorphism in cytochrome P4502A6 reduces the risk to head and neck cancer and modifies the treatment outcome. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:502-511. [PMID: 34655463 DOI: 10.1002/em.22466] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/26/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
The present case-control study consisting of 1300 cases of head and neck squamous cell carcinoma (HNSCC) and the equal number of controls aimed to investigate the association of functionally important polymorphisms in cytochrome P4502A6 (CYP2A6*1B, CYP2A6*4C, CYP2A6*9-rs28399433) with HNSCC and the treatment response in cases receiving a combination of chemotherapy/radiotherapy (CT/RT). A significant decrease in risk to HNSCC was observed in the cases with deletion (CYP2A6*4B and CYP2A6*4C) or reduced activity genotypes (CYP2A6*9) of CYP2A6. This risk to HNSCC was further reduced significantly in tobacco users among the cases when compared to nontobacco users among the cases. The risk was also reduced to a slightly greater extent in alcohol users among the cases when compared to nonalcohol users among the cases. In contrast with decreased risk to HNSCC, almost half of the cases with variant genotypes of CYP2A6 (CYP2A6*1A/*4C+*1B/*4C+*4C/*4C and *9/*9) did not respond to the treatment. Likewise, the survival rate in cases receiving the treatment, after 55 months of follow-up was significantly lower in cases with deletion (6.3%) or reduced activity (11.9%) allele than in the cases with common alleles (41%). The present study has shown that CYP2A6 polymorphism significantly reduces the risk to HNSCC. Our data further suggested that CYP2A6 polymorphism may worsen the treatment outcome in the cases receiving CT/RT.
Collapse
Affiliation(s)
- Vinay Kumar Yadav
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Tridiv Katiyar
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Munindra Ruwali
- Faculty of Science, Engineering And Technology, Amity University, Gurgaon, India
| | - Sanjay Yadav
- All India Institute of Medical Sciences, Raebareli, India
| | - Sudhir Singh
- Department of Radiotherapy, King George's Medical University, Lucknow, India
| | - Rahat Hadi
- Department of Radiation Oncology, Dr Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India
| | | | - Devendra Parmar
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| |
Collapse
|
7
|
Kovar L, Selzer D, Britz H, Benowitz N, St Helen G, Kohl Y, Bals R, Lehr T. Comprehensive Parent-Metabolite PBPK/PD Modeling Insights into Nicotine Replacement Therapy Strategies. Clin Pharmacokinet 2021; 59:1119-1134. [PMID: 32166575 PMCID: PMC7467963 DOI: 10.1007/s40262-020-00880-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Background Nicotine, the pharmacologically active substance in both tobacco and many electronic cigarette (e-cigarette) liquids, is responsible for the addiction that sustains cigarette smoking. With 8 million deaths worldwide annually, smoking remains one of the major causes of disability and premature death. However, nicotine also plays an important role in smoking cessation strategies. Objectives The aim of this study was to develop a comprehensive, whole-body, physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model of nicotine and its major metabolite cotinine, covering various routes of nicotine administration, and to simulate nicotine brain tissue concentrations after the use of combustible cigarettes, e-cigarettes, nicotine gums, and nicotine patches. Methods A parent–metabolite, PBPK/PD model of nicotine for a non-smoking and a smoking population was developed using 91 plasma and brain tissue concentration–time profiles and 11 heart rate profiles. Among others, cytochrome P450 (CYP) 2A6 and 2B6 enzymes were implemented, including kinetics for CYP2A6 poor metabolizers. Results The model is able to precisely describe and predict both nicotine plasma and brain tissue concentrations, cotinine plasma concentrations, and heart rate profiles. 100% of the predicted area under the concentration–time curve (AUC) and maximum concentration (Cmax) values meet the twofold acceptance criterion with overall geometric mean fold errors of 1.12 and 1.15, respectively. The administration of combustible cigarettes, e-cigarettes, nicotine patches, and nicotine gums was successfully implemented in the model and used to identify differences in steady-state nicotine brain tissue concentration patterns. Conclusions Our PBPK/PD model may be helpful in further investigations of nicotine dependence and smoking cessation strategies. As the model represents the first nicotine PBPK/PD model predicting nicotine concentration and heart rate profiles after the use of e-cigarettes, it could also contribute to a better understanding of the recent increase in youth e-cigarette use. Electronic supplementary material The online version of this article (10.1007/s40262-020-00880-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lukas Kovar
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany
| | - Dominik Selzer
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany
| | - Hannah Britz
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany
| | - Neal Benowitz
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Gideon St Helen
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Yvonne Kohl
- Fraunhofer Institute for Biomedical Engineering IBMT, Sulzbach, Germany
| | - Robert Bals
- Department of Internal Medicine V, Saarland University, Homburg, Germany
| | - Thorsten Lehr
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany.
| |
Collapse
|
8
|
Perez-Paramo YX, Lazarus P. Pharmacogenetics factors influencing smoking cessation success; the importance of nicotine metabolism. Expert Opin Drug Metab Toxicol 2021; 17:333-349. [PMID: 33322962 PMCID: PMC8049967 DOI: 10.1080/17425255.2021.1863948] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/10/2020] [Indexed: 01/12/2023]
Abstract
Introduction: Smoking remains a worldwide epidemic, and despite an increase in public acceptance of the harms of tobacco use, it remains the leading cause of preventable death. It is estimated that up to 70% of all smokers express a desire to quit, but only 3-5% of them are successful.Areas covered: The goal of this review was to evaluate the current status of smoking cessation treatments and the feasibility of implementing personalized-medicine approaches to these pharmacotherapies. We evaluated the genetics associated with higher levels of nicotine addiction and follow with an analysis of the genetic variants that affect the nicotine metabolic ratio (NMR) and the FDA approved treatments for smoking cessation. We also highlighted the gaps in the process of translating current laboratory understanding into clinical practice, and the benefits of personalized treatment approaches for a successful smoking cessation strategy.Expert opinion: Evidence supports the use of tailored therapies to ensure that the most efficient treatments are utilized in an individual's smoking cessation efforts. An understanding of the genetic effects on the efficacy of individualized smoking cessation pharmacotherapies is key to smoking cessation, ideally utilizing a polygenetic risk score that considers all genetic variation.
Collapse
Affiliation(s)
- Yadira X. Perez-Paramo
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington, USA
| | - Philip Lazarus
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington, USA
| |
Collapse
|
9
|
Hsieh CJ, Sun M, Osborne G, Ricker K, Tsai FC, Li K, Tomar R, Phuong J, Schmitz R, Sandy MS. Cancer Hazard Identification Integrating Human Variability: The Case of Coumarin. Int J Toxicol 2019; 38:501-552. [PMID: 31845612 DOI: 10.1177/1091581819884544] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Coumarin is a naturally occurring sweet-smelling benzopyrone that may be extracted from plants or synthesized for commercial uses. Its uses include as a flavoring agent, fragrance enhancer, and odor-masking additive. We reviewed and evaluated the scientific evidence on the carcinogenicity of coumarin, integrating information from carcinogenicity studies in animals with mechanistic and other relevant data, including data from toxicogenomic, genotoxicity, and metabolism studies, and studies of human variability of a key enzyme, CYP2A6. Increases in tumors were observed in multiple studies in rats and mice in multiple tissues. Our functional pathway analysis identified several common cancer-related biological processes/pathways affected by coumarin in rat liver following in vivo exposure and in human primary hepatocytes exposed in vitro. When coumarin 7-hydroxylation by CYP2A6 is compromised, this can lead to a shift in metabolism to the 3,4-epoxidation pathway and increased generation of electrophilic metabolites. Mechanistic data align with 3 key characteristics of carcinogens, namely formation of electrophilic metabolites, genotoxicity, and induction of oxidative stress. Considerations of metabolism, human variability in CYP2A6 activity, and coumarin hepatotoxicity in susceptible individuals provide additional support for carcinogenicity concern. Our analysis illustrates the importance of integrating information on human variability in the cancer hazard identification process.
Collapse
Affiliation(s)
- ChingYi Jennifer Hsieh
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Meng Sun
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Gwendolyn Osborne
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Karin Ricker
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Feng C Tsai
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Kate Li
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Rajpal Tomar
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA.,Retired
| | - Jimmy Phuong
- Department of Biomedical and Health Informatics, University of Washington, Seattle, WA, USA
| | - Rose Schmitz
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| | - Martha S Sandy
- Office of Environmental Health Hazard Assessment, CalEPA, Sacramento and Oakland, CA, USA
| |
Collapse
|
10
|
Challenges to assess substrate-dependent allelic effects in CYP450 enzymes and the potential clinical implications. THE PHARMACOGENOMICS JOURNAL 2019; 19:501-515. [DOI: 10.1038/s41397-019-0105-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 09/09/2019] [Accepted: 10/02/2019] [Indexed: 12/12/2022]
|
11
|
Zhou Y, Mkrtchian S, Kumondai M, Hiratsuka M, Lauschke VM. An optimized prediction framework to assess the functional impact of pharmacogenetic variants. THE PHARMACOGENOMICS JOURNAL 2018; 19:115-126. [PMID: 30206299 PMCID: PMC6462826 DOI: 10.1038/s41397-018-0044-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 06/27/2018] [Accepted: 08/10/2018] [Indexed: 01/25/2023]
Abstract
Prediction of phenotypic consequences of mutations constitutes an important aspect of precision medicine. Current computational tools mostly rely on evolutionary conservation and have been calibrated on variants associated with disease, which poses conceptual problems for assessment of variants in poorly conserved pharmacogenes. Here, we evaluated the performance of 18 current functionality prediction methods leveraging experimental high-quality activity data from 337 variants in genes involved in drug metabolism and transport and found that these models only achieved probabilities of 0.1–50.6% to make informed conclusions. We therefore developed a functionality prediction framework optimized for pharmacogenetic assessments that significantly outperformed current algorithms. Our model achieved 93% for both sensitivity and specificity for both loss-of-function and functionally neutral variants, and we confirmed its superior performance using cross validation analyses. This novel model holds promise to improve the translation of personal genetic information into biological conclusions and pharmacogenetic recommendations, thereby facilitating the implementation of Next-Generation Sequencing data into clinical diagnostics.
Collapse
Affiliation(s)
- Yitian Zhou
- Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Souren Mkrtchian
- Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Masaki Kumondai
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
| |
Collapse
|
12
|
Ezzeldin N, El-Lebedy D, Darwish A, El Bastawisy A, Abd Elaziz SH, Hassan MM, Saad-Hussein A. Association of genetic polymorphisms CYP2A6*2 rs1801272 and CYP2A6*9 rs28399433 with tobacco-induced lung Cancer: case-control study in an Egyptian population. BMC Cancer 2018; 18:525. [PMID: 29724170 PMCID: PMC5934827 DOI: 10.1186/s12885-018-4342-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 04/08/2018] [Indexed: 11/10/2022] Open
Abstract
Background Several studies have reported the role of CYP2A6 genetic polymorphisms in smoking and lung cancer risk with some contradictory results in different populations. The purpose of the current study is to assess the contribution of the CYP2A6*2 rs1801272 and CYP2A6*9 rs28399433 gene polymorphisms and tobacco smoking in the risk of lung cancer in an Egyptian population. Methods A case-control study was conducted on 150 lung cancer cases and 150 controls. All subjects were subjected to blood sampling for Extraction of genomic DNA and Genotyping of the CYP2A6 gene SNPs (CYP2A6*2 (1799 T > A) rs1801272 and CYP2A6*9 (− 48 T > G) rs28399433 by Real time PCR. Results AC and CC genotypes were detected in CYP2A6*9; and AT genotype in CYP2A6*2. The frequency of CYP2A6*2 and CYP2A6*9 were 0.7% and 3.7% respectively in the studied Egyptian population. All cancer cases with slow metabolizer variants were NSCLC. Non-smokers represented 71.4% of the CYP2A6 variants. There was no statistical significant association between risk of lung cancer, smoking habits, heaviness of smoking and the different polymorphisms of CYP2A6 genotypes. Conclusion The frequency of slow metabolizers CYP2A6*2 and CYP2A6*9 are poor in the studied Egyptian population. Our findings did not suggest any association between CYP2A6 genotypes and risk of lung cancer.
Collapse
Affiliation(s)
- Nada Ezzeldin
- Chest Diseases, National Research Center, Cairo, Egypt
| | | | - Amira Darwish
- Medical Oncology, National Cancer Institute, Cairo University, Cairo, Egypt. .,National Cancer Institute (NCI), Fom-Elkhalig Square, P.O.Box: 11796, Cairo, Egypt.
| | - Ahmed El Bastawisy
- Medical Oncology, National Cancer Institute, Cairo University, Cairo, Egypt
| | | | | | - Amal Saad-Hussein
- Environmental Health & Preventive Medicine, National Research Center, Cairo, Egypt
| |
Collapse
|
13
|
A randomized phase II study of S-1 versus capecitabine as first-line chemotherapy in elderly metastatic gastric cancer patients with or without poor performance status. Pharmacogenet Genomics 2018; 28:23-30. [DOI: 10.1097/fpc.0000000000000320] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
14
|
Tanner JA, Tyndale RF. Variation in CYP2A6 Activity and Personalized Medicine. J Pers Med 2017; 7:jpm7040018. [PMID: 29194389 PMCID: PMC5748630 DOI: 10.3390/jpm7040018] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 11/17/2017] [Accepted: 11/27/2017] [Indexed: 12/16/2022] Open
Abstract
The cytochrome P450 2A6 (CYP2A6) enzyme metabolizes several clinically relevant substrates, including nicotine-the primary psychoactive component in cigarette smoke. The gene that encodes the CYP2A6 enzyme is highly polymorphic, resulting in extensive interindividual variation in CYP2A6 enzyme activity and the rate of metabolism of nicotine and other CYP2A6 substrates including cotinine, tegafur, letrozole, efavirenz, valproic acid, pilocarpine, artemisinin, artesunate, SM-12502, caffeine, and tyrosol. CYP2A6 expression and activity are also impacted by non-genetic factors, including induction or inhibition by pharmacological, endogenous, and dietary substances, as well as age-related changes, or interactions with other hepatic enzymes, co-enzymes, and co-factors. As variation in CYP2A6 activity is associated with smoking behavior, smoking cessation, tobacco-related lung cancer risk, and with altered metabolism and resulting clinical responses for several therapeutics, CYP2A6 expression and enzyme activity is an important clinical consideration. This review will discuss sources of variation in CYP2A6 enzyme activity, with a focus on the impact of CYP2A6 genetic variation on metabolism of the CYP2A6 substrates.
Collapse
Affiliation(s)
- Julie-Anne Tanner
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON M5T 1R8, Canada.
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada.
| | - Rachel F Tyndale
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON M5T 1R8, Canada.
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada.
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada.
| |
Collapse
|
15
|
Tanner JA, Henderson JA, Buchwald D, Howard BV, Henderson PN, Tyndale RF. Variation in CYP2A6 and nicotine metabolism among two American Indian tribal groups differing in smoking patterns and risk for tobacco-related cancer. Pharmacogenet Genomics 2017; 27:169-178. [PMID: 28181923 PMCID: PMC5382092 DOI: 10.1097/fpc.0000000000000271] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The Northern Plains (NP) and Southwest (SW) American Indian populations differ in their smoking patterns and lung cancer incidence. We aimed to compare CYP2A6 genetic variation and CYP2A6 enzyme activity (representative of the rate of nicotine metabolism) between the two tribal populations as these have previously been associated with differences in smoking, quitting, and lung cancer risk. PARTICIPANTS AND METHODS American Indians (N=636) were recruited from two different tribal populations (NP in South Dakota, SW in Arizona) as part of a study carried out as part of the Collaborative to Improve Native Cancer Outcomes P50 Project. A questionnaire assessed smoking-related traits and demographics. Participants were genotyped for CYP2A6 genetic variants *1B, *2, *4, *7, *9, *12, *17, and *35. Plasma and/or saliva samples were used to measure nicotine's metabolites cotinine and 3'-hydroxycotinine and determine CYP2A6 activity (3'-hydroxycotinine/cotinine, i.e. the nicotine metabolite ratio, NMR). RESULTS The overall frequency of genetically reduced nicotine metabolizers, those with CYP2A6 decrease-of-function or loss-of-function alleles, was lower in the NP compared with the SW (P=0.0006). The CYP2A6 genotype was associated with NMR in both tribal groups (NP, P<0.0001; SW, P=0.04). Notably, the rate of nicotine metabolism was higher in NP compared with SW smokers (P=0.03), and in comparison with other ethnic groups in the USA. Of the variables studied, the CYP2A6 genotype was the only variable to significantly independently influence NMR among smokers in both tribal populations (NP, P<0.001; SW, P=0.05). CONCLUSION Unique CYP2A6 allelic patterns and rates of nicotine metabolism among these American Indian populations suggest different risks for smoking, and tobacco-related disease.
Collapse
Affiliation(s)
- Julie-Anne Tanner
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | | | - Dedra Buchwald
- Elson S. Floyd College of Medicine, Initiative for Research and Education to Advance Community Health (IREACH), Washington State University, Seattle, Washington
| | - Barbara V. Howard
- MedStar Health Research Institute, Hyattsville, Maryland; the Georgetown-Howard Universities Center for Clinical and Translational Sciences, Washington, District of Columbia
| | | | - Rachel F. Tyndale
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
16
|
López-Flores LA, Pérez-Rubio G, Falfán-Valencia R. Distribution of polymorphic variants of CYP2A6 and their involvement in nicotine addiction. EXCLI JOURNAL 2017; 16:174-196. [PMID: 28507465 PMCID: PMC5427481 DOI: 10.17179/excli2016-847] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/13/2017] [Indexed: 01/08/2023]
Abstract
Tobacco consumption has become a major public health issue, which has motivated studies to identify and understand the biological processes involved in the smoking behavior for prevention and smoking cessation treatments. CYP2A6 has been identified as the main gene that codifies the enzyme that metabolizes nicotine. Many alleles have been identified after the discovery of CYP2A6, suggesting a wide interethnic variability and a diverse smoking behavior of the allele carrying individuals. The main purpose of this review is to update and highlight the effects of the CYP2A6 gene variability related to tobacco consumption reported from diverse human populations. The review further aims to consider CYP2A6 in future studies as a possible genetic marker for the prevention and treatment of nicotine addiction. Therefore, we analyzed several population studies and their importance at addressing and characterizing a population using specific parameters. Our efforts may contribute to a personalized system for detecting, preventing and treating populations at a higher risk of smoking to avoid diseases related to tobacco consumption.
Collapse
|
17
|
Jeong JH, Park SR, Ahn Y, Ryu MH, Ryoo BY, Kong SY, Yook JH, Yoo MW, Kim BS, Kim BS, Kang YK. Associations between CYP2A6 polymorphisms and outcomes of adjuvant S-1 chemotherapy in patients with curatively resected gastric cancer. Gastric Cancer 2017; 20:146-155. [PMID: 26715117 DOI: 10.1007/s10120-015-0586-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/07/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Oral fluoropyrimidine S-1 contains tegafur, which is metabolized to 5-fluorouracil by cytochrome P450 2A6 (CYP2A6). We here examined associations between CYP2A6 polymorphisms and treatment outcomes of adjuvant S-1 in gastric cancer patients. METHODS Patients received adjuvant S-1 (40 mg/m2 twice daily, days 1-28, every 6 weeks for eight cycles) after curative surgery for pathological stage II-III gastric cancer. We analyzed the wild-type allele (W) (CYP2A6*1) and four variant alleles (V) (CYP2A6*4, *7, *9, *10) that abolish or reduce this enzyme activity. RESULTS Patients (n = 200) were enrolled between November 2007 and July 2013 with the following clinical characteristics: median age, 57 years (range, 32-83 years); 128 men, 72 women. With a median follow-up of 46.4 months, the 3-year relapse-free survival (RFS) and overall survival (OS) rates were 83.1 % (95 % CI, 77.7-88.5 %) and 94.8 % (95 % CI, 91.6-98.0 %), respectively. Genotype distributions were as follows: W/W (n = 49, 24.5 %), W/V (n = 94, 47.0 %), and V/V (n = 57, 28.5 %). Overall toxicity did not differ according to genotype for any grade (p = 0.612) or grade ≥3 (p = 0.143). However, RFS differed significantly according to CYP2A6 genotype. The 3-year RFS rates were 95.9 % for W/W, 83.1 % for W/V, and 72.5 % for V/V (p = 0.032). Carriers of W/V and V/V genotypes had a poorer RFS with a hazard ratio of 3.41 (95 % CI, 1.01-11.52; p = 0.049) and 4.03 (95 % CI, 1.16-13.93; p = 0.028), respectively, compared with the W/W genotype. CONCLUSIONS CYP2A6 polymorphisms are not associated with toxicity of S-1 chemotherapy, but correlate with the efficacy of S-1 in the adjuvant setting for gastric cancer.
Collapse
Affiliation(s)
- Jae Ho Jeong
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea
| | - Sook Ryun Park
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea
| | - Yongchel Ahn
- Department of Hematology and Oncology, Gangneung Asan Hospital, 38, Bangdong-gil, Sacheon-myeon, Gangneung, Republic of Korea
| | - Min-Hee Ryu
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea
| | - Baek-Yeol Ryoo
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea
| | - Sun-Young Kong
- Department of Laboratory Medicine, Center for Diagnostic Oncology, Research Institute and Hospital, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang, Republic of Korea
| | - Jeong Hwan Yook
- Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Republic of Korea
| | - Moon-Won Yoo
- Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Republic of Korea
| | - Beom Su Kim
- Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Republic of Korea
| | - Byung Sik Kim
- Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Republic of Korea
| | - Yoon-Koo Kang
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
| |
Collapse
|
18
|
Fattore L, Diana M. Drug addiction: An affective-cognitive disorder in need of a cure. Neurosci Biobehav Rev 2016; 65:341-61. [DOI: 10.1016/j.neubiorev.2016.04.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/24/2016] [Accepted: 04/11/2016] [Indexed: 12/22/2022]
|
19
|
Park SL, Tiirikainen MI, Patel YM, Wilkens LR, Stram DO, Le Marchand L, Murphy SE. Genetic determinants of CYP2A6 activity across racial/ethnic groups with different risks of lung cancer and effect on their smoking intensity. Carcinogenesis 2016; 37:269-279. [PMID: 26818358 DOI: 10.1093/carcin/bgw012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/19/2016] [Indexed: 01/22/2023] Open
Abstract
Genetic variation in cytochrome P450 2A6 (CYP2A6) gene is the primary contributor to the intraindividual and interindividual differences in nicotine metabolism and has been found to influence smoking intensity. However, no study has evaluated the relationship between CYP2A6 genetic variants and the CYP2A6 activity ratio (total 3-hydroxycotinine/cotinine) and their influence on smoking intensity [total nicotine equivalents (TNE)], across five racial/ethnic groups found to have disparate rates of lung cancer. This study genotyped 10 known functional CYP2A6 genetic or copy number variants in 2115 current smokers from the multiethnic cohort study [African Americans (AA) = 350, Native Hawaiians (NH) = 288, Whites = 413, Latinos (LA) = 437 and Japanese Americans (JA) = 627] to conduct such an investigation. Here, we found that LA had the highest CYP2A6 activity followed by Whites, AA, NH and JA, who had the lowest levels. Adjusting for age, sex, race/ethnicity and body mass index, we found that CYP2A6 diplotypes were predictive of TNE levels, particularly in AA and JA (P trend < 0.0001). However, only in JA did the association remain after accounting for cigarettes per day. Also, it is only in this population that the lower activity ratio supports lower TNE levels, carcinogen exposure and thereby lower risk of lung cancer. Despite the association between nicotine metabolism (CYP2A6 activity phenotype and diplotypes) and smoking intensity (TNE), CYP2A6 levels did not correlate with the higher TNE levels found in AA nor the lower TNE levels found in LA, suggesting that other factors may influence smoking dose in these populations. Therefore, further study in these populations is recommended.
Collapse
Affiliation(s)
| | - Maarit I Tiirikainen
- Epidemiology Program, University of Hawaii Cancer Center , Honolulu, HI 96813 , USA and
| | | | - Lynne R Wilkens
- Epidemiology Program, University of Hawaii Cancer Center , Honolulu, HI 96813 , USA and
| | | | - Loic Le Marchand
- Epidemiology Program, University of Hawaii Cancer Center , Honolulu, HI 96813 , USA and
| | - Sharon E Murphy
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, University of Minnesota , 2231 6th Street SE, 2-127 CCRB, Minneapolis, MN 55455 , USA
| |
Collapse
|
20
|
Kumondai M, Hosono H, Orikasa K, Arai Y, Arai T, Sugimura H, Ozono S, Sugiyama T, Takayama T, Sasaki T, Hirasawa N, Hiratsuka M. Genetic Polymorphisms of CYP2A6 in a Case-Control Study on Bladder Cancer in Japanese Smokers. Biol Pharm Bull 2016; 39:84-9. [DOI: 10.1248/bpb.b15-00604] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Masaki Kumondai
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Hiroki Hosono
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Kazuhiko Orikasa
- Kesen-numa City Hospital
- Department of Urology, Tohoku University
| | | | - Tomio Arai
- Department of Pathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
| | - Haruhiko Sugimura
- Department of Tumor Pathology, Hamamatsu University School of Medicine
| | - Seiichiro Ozono
- Department of Urology, Hamamatsu University School of Medicine
| | | | | | - Takamitsu Sasaki
- Department of Environmental and Health Science, Tohoku Pharmaceutical University
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University
| |
Collapse
|
21
|
Wassenaar CA, Zhou Q, Tyndale RF. CYP2A6 genotyping methods and strategies using real-time and end point PCR platforms. Pharmacogenomics 2015; 17:147-62. [PMID: 26670214 DOI: 10.2217/pgs.15.156] [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] [Indexed: 11/21/2022] Open
Abstract
CYP2A6 genotyping is of clinical importance--CYP2A6 gene variants influence nicotine metabolism and are associated with nicotine dependence, cigarettes per day, smoking cessation and the risk for tobacco-associated cancers. CYP2A6 gene variants also influence the metabolism of therapeutic drugs, such as the anticancer agents, tegafur and letrozole. Over the years, CYP2A6 genotyping methods have evolved to incorporate novel gene variants and to circumvent genotyping errors resulting from the high degree of homology between CYP2A6 and neighboring CYP2A genes. Herein, CYP2A6 genotyping strategies are described for commonly genotyped functionally significant alleles including SNPs, small insertions/deletions and more complex structural variants. The methods presented utilize higher throughput SYBR green real-time PCR technology in addition to standard thermocycling.
Collapse
Affiliation(s)
- Catherine A Wassenaar
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
| | - Qian Zhou
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
| | - Rachel F Tyndale
- Campbell Family Mental Health Research Institute, Centre for Addiction & Mental Health (CAMH), Departments of Pharmacology & Toxicology & Psychiatry, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
| |
Collapse
|
22
|
Hosono H, Kumondai M, Arai T, Sugimura H, Sasaki T, Hirasawa N, Hiratsuka M. CYP2A6 genetic polymorphism is associated with decreased susceptibility to squamous cell lung cancer in Japanese smokers. Drug Metab Pharmacokinet 2015; 30:263-8. [DOI: 10.1016/j.dmpk.2015.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 04/06/2015] [Accepted: 04/08/2015] [Indexed: 11/30/2022]
|
23
|
Yamamiya I, Yoshisue K, Ishii Y, Yamada H, Chiba M. Effect of CYP2A6 genetic polymorphism on the metabolic conversion of tegafur to 5-fluorouracil and its enantioselectivity. Drug Metab Dispos 2014; 42:1485-92. [PMID: 25002745 DOI: 10.1124/dmd.114.058008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tegafur (FT), a prodrug of 5-fluorouracil, is a chiral molecule, a racemate of R- and S-isomers, and CYP2A6 plays an important role in the enantioselective metabolism of FT in human liver microsomes (R-FT >> S-FT). This study examined the enantioselective metabolism of FT by microsomes prepared from Sf9 cells expressing wild-type CYP2A6 and its variants (CYP2A6*7, *8, *10, and *11) that are highly prevalent in the Asian population. We also investigated the metabolism of coumarin and nicotine, both CYP2A6 probe drugs, in these variants. Enzyme kinetic analyses showed that CYP2A6.7 (I471T) and CYP2A6.10 (I471T and R485L) had markedly lower Vmax values for both enantiomers than wild-type enzyme (CYP2A6.1) and other variant enzymes, whereas Km values were higher in most of the variant enzymes for both enantiomers than CYP2A6.1. The ratios of Vmax and Km values for R-FT to corresponding values for S-FT (R/S ratio) were similar among enzymes, indicating little difference in enantioselectivity among the wild-type and variant enzymes. Similarly, both CYP2A6.7 and CYP2A6.10 had markedly lower Vmax values for coumarin 7-hydroxylase and nicotine C-oxidase activities than CYP2A6.1 and other variant enzymes, whereas Km values were higher in most of the variant enzymes for both activities than CYP2A6.1. In conclusion, the amino acid substitutions in CYP2A6 variants generally resulted in lower affinity for substrates, while Vmax values were selectively reduced in CYP2A6.7 and CYP2A6.10. Consistent R/S ratios among CYP2A6.1 and variant enzymes indicated that the amino acid substitutions had little effect on enantioselectivity in the metabolism of FT.
Collapse
Affiliation(s)
- Ikuo Yamamiya
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Kunihiro Yoshisue
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Yuji Ishii
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Hideyuki Yamada
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Masato Chiba
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| |
Collapse
|
24
|
Yang L, Yang Y, Qin Q, Zhou A, Zhao J, Wang J, Shu C, Yuan X, Hu S. Dose-finding study on adjuvant chemotherapy with S-1 plus oxaliplatin for gastric cancer. Mol Clin Oncol 2013; 2:93-98. [PMID: 24649314 DOI: 10.3892/mco.2013.191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/11/2013] [Indexed: 01/27/2023] Open
Abstract
Gastric cancer (GC) is the fourth most common type of cancer, accounting for an estimated one million new cases annually worldwide. Locally advanced GC often recurs, even following curative surgical resection. Therefore, there is a need for an effective adjuvant chemotherapy regimen. The aim of this trial was to investigate the maximum tolerated dose (MTD) of S-1 when administered in combination with oxaliplatin in postoperative GC patients. Oxaliplatin was administered at a fixed dose of 130 mg/m2 on day 1. S-1 was administered from day 1 to 14 of a 3-week cycle and escalated by 10 mg/m2/day from 60 to 80 mg/m2/day. A total of 15 patients were enrolled in this study. No dose-limiting toxicities (DLTs) occurred at level 1 (S-1, 60 mg/m2; n=3). One case of DLT (grade 3 vomiting) occurred at level 2 (S-1, 70 mg/m2; n= 6), whereas 2 cases of grade 3 vomiting were observed at level 3 (S-1, 80 mg/m2; n=6). Based on these results, the MTD of S-1 was initially determined to be 70 mg/m2. Furthermore, we observed that cytochrome P450 2A6 (CYP2A6) 41349640C>G was associated with severe neutropenia (C/C vs. C/G vs. G/G = 0 vs. 33.33 vs. 100%; P=0.03297, Fisher's exact test) during the entire course of the treatment.
Collapse
Affiliation(s)
- Lin Yang
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021
| | - Yi Yang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Qiong Qin
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021
| | - Aiping Zhou
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021
| | - Jianjun Zhao
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021
| | - Jinwan Wang
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021
| | - Chang Shu
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Xinghua Yuan
- Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021
| | - Songnian Hu
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| |
Collapse
|
25
|
Martiny VY, Miteva MA. Advances in molecular modeling of human cytochrome P450 polymorphism. J Mol Biol 2013; 425:3978-92. [PMID: 23856621 DOI: 10.1016/j.jmb.2013.07.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 01/08/2023]
Abstract
Cytochrome P450 (CYP) is a supergene family of metabolizing enzymes involved in the phase I metabolism of drugs and endogenous compounds. CYP oxidation often leads to inactive drug metabolites or to highly toxic or carcinogenic metabolites involved in adverse drug reactions (ADR). During the last decade, the impact of CYP polymorphism in various drug responses and ADR has been demonstrated. Of the drugs involved in ADR, 56% are metabolized by polymorphic phase I metabolizing enzymes, 86% among them being CYP. Here, we review the major CYP polymorphic forms, their impact for drug response and current advances in molecular modeling of CYP polymorphism. We focus on recent studies exploring CYP polymorphism performed by the use of sequence-based and/or protein-structure-based computational approaches. The importance of understanding the molecular mechanisms related to CYP polymorphism and drug response at the atomic level is outlined.
Collapse
Affiliation(s)
- Virginie Y Martiny
- Université Paris Diderot, Sorbonne Paris Cité, Molécules Thérapeutiques In Silico, Inserm UMR-S 973, 35 rue Helene Brion, 75013 Paris, France; Inserm, U973, F-75205 Paris, France
| | | |
Collapse
|
26
|
Liu YL, Xu Y, Li F, Chen H, Guo SL. CYP2A6 deletion polymorphism is associated with decreased susceptibility of lung cancer in Asian smokers: a meta-analysis. Tumour Biol 2013; 34:2651-7. [PMID: 23649654 DOI: 10.1007/s13277-013-0815-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Accepted: 04/18/2013] [Indexed: 11/28/2022] Open
Abstract
Cytochrome P450 2A6 (CYP2A6) is an enzyme involved in the metabolism of some tobacco carcinogens, which is an important risk factor of lung cancer. Among CYP2A6 allelic variants, CYP2A6*4 presents a whole gene deletion that accounts for the majority of poor metabolizer. In this study, a meta-analysis was performed to assess the association between CYP2A6*4 and risk of lung cancer. Literature searches were conducted to identify peer-reviewed manuscripts published up to December 20, 2012. Pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were calculated in a fixed-effects model and a random-effects model when appropriate. Eight eligible studies with 3,203 lung cancer cases and 2,839 controls were included in this study. Overall, no significant association was observed in CYP2A6*4 with the risk of lung cancer under any genetic model for all samples after correction. However, subgroup analysis showed that significant associations were observed in Asian with pooled OR (95 %CI) of 0.761 (0.672-0.861) for allele comparison, 0.769 (0.668-0.886) for dominant model, and 0.522 (0.359-0.760) for recessive model. Furthermore, after stratifying Asian samples according to smoking status, significant associations were only observed in smokers with pooled OR (95 %CI) of 0.713 (0.607-0.838) for allele comparison, 0.720 (0.596-0.869) for dominant model, and 0.444 (0.275-0.715) for recessive model. This meta-analysis suggests that the CYP2A6*4 polymorphism was associated with susceptibility of lung cancer for smokers in Asian. The whole gene deletion of CYP2A6 might decrease the risk of tobacco-related lung cancer in Asian.
Collapse
Affiliation(s)
- Yu-liang Liu
- Department of Respiratory Medicine, The first affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | | | | | | | | |
Collapse
|
27
|
Wang L, Zang W, Liu J, Xie D, Ji W, Pan Y, Li Z, Shen J, Shi Y. Association of CYP2A6*4 with susceptibility of lung cancer: a meta-analysis. PLoS One 2013; 8:e59556. [PMID: 23585826 DOI: 10.1371/journal.pone.0059556] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 02/15/2013] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To assess the association between the variant of Cytochrome P450 2A6 whole gene deletion (CYP2A6*4) polymorphism and risk of lung cancer. METHODS Two investigators independently searched the PubMed, Elsevier, EMBASE, Web of Science, Wiley Online Library and Chinese National Knowledge Infrastructure (CNKI). Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for CYP2A6*4 and lung cancer were calculated in a fixed-effects model (the Mantel-Haenszel method) and a random-effects model (the DerSimonian and Laird method) when appropriate. RESULTS This meta-analysis included seven eligible studies, which included 2524 lung cancer cases and 2258 controls (cancer-free). Overall, CYP2A6*4 was associated with the risk of lung cancer (allele*4 vs. allele non-*4, pooled OR = 0.826, 95% CI = 0.725-0.941, P-value = 0.004). When stratifying for population, significant association was observed in Asian (additive model, pooled OR = 0.794, 95% CI = 0.694-0.909, P-value = 0.001; dominant model, pooled OR = 0.827, 95% CI = 0.709-0.965, P-value = 0.016; recessive model (pooled OR = 0.444, 95% CI = 0.293-0.675, P-value <0.0001). In the overall analysis, a comparably significant decrease in the frequency of *4/*4 genotype was detected between cases and controls in Asian while no *4/*4 genotype was detected in Caucasian in collected data. CONCLUSION This meta-analysis suggests that the CYP2A6*4 polymorphism is associated with susceptibility of lung cancer in Asian. The whole gene deletion of CYP2A6 may decrease the risk of lung cancer in Asian samples.
Collapse
Affiliation(s)
- Lishan Wang
- Bio-X Institutes and Affiliated Changning Mental Health Center, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
PharmGKB summary: very important pharmacogene information for cytochrome P-450, family 2, subfamily A, polypeptide 6. Pharmacogenet Genomics 2013; 22:695-708. [PMID: 22547082 DOI: 10.1097/fpc.0b013e3283540217] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
29
|
Zhu AZX, Renner CC, Hatsukami DK, Swan GE, Lerman C, Benowitz NL, Tyndale RF. The ability of plasma cotinine to predict nicotine and carcinogen exposure is altered by differences in CYP2A6: the influence of genetics, race, and sex. Cancer Epidemiol Biomarkers Prev 2013; 22:708-18. [PMID: 23371292 DOI: 10.1158/1055-9965.epi-12-1234-t] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Cotinine, a nicotine metabolite, is a biomarker of tobacco, nicotine, and carcinogen exposure. However, a given cotinine level may not represent the same tobacco exposure; for example, African-Americans have higher cotinine levels than Caucasians after controlling for exposure. METHODS Cotinine levels are determined by the amount of cotinine formation and the rate of cotinine removal, which are both mediated by the enzyme CYP2A6. Because CYP2A6 activity differs by sex (estrogen induces CYP2A6) and genotype, their effect on cotinine formation and removal was measured in nonsmoking Caucasians (Study 1, n = 181) infused with labeled nicotine and cotinine. The findings were then extended to ad libitum smokers (Study 2, n = 163). RESULTS Study 1: Reduced CYP2A6 activity altered cotinine formation less than cotinine removal resulting in ratios of formation to removal of 1.31 and 1.12 in CYP2A6 reduced and normal metabolizers (P = 0.01), or 1.39 and 1.12 in males and females (P = 0.001), suggesting an overestimation of tobacco exposure in slower metabolizers. Study 2: Cotinine again overestimated tobacco and carcinogen exposure by 25% or more in CYP2A6 reduced metabolizers (≈2-fold between some genotypes) and in males. CONCLUSIONS In people with slower relative to faster CYP2A6 activity, cotinine accumulates resulting in substantial differences in cotinine levels for a given tobacco exposure. IMPACT Cotinine levels may be misleading when comparing those with differing CYP2A6 genotypes within a race, between races with differing frequencies of CYP2A6 gene variants (i.e., African-Americans have higher frequencies of reduced function variants contributing to their higher cotinine levels), or between the sexes.
Collapse
Affiliation(s)
- Andy Z X Zhu
- Departments of Psychiatry, Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
30
|
Tanii H, Shitara Y, Torii M, Sekine S, Iwata H, Horie T. Induction of Cytochrome P450 2A6 by Bilirubin in Human Hepatocytes. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/pp.2013.42026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
31
|
Djordjevic N, Carrillo JA, van den Broek MP, Kishikawa J, Roh HK, Bertilsson L, Aklillu E. Comparisons of CYP2A6 Genotype and Enzyme Activity between Swedes and Koreans. Drug Metab Pharmacokinet 2013; 28:93-7. [DOI: 10.2133/dmpk.dmpk-12-rg-029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
32
|
Uno T, Obe Y, Ogura C, Goto T, Yamamoto K, Nakamura M, Kanamaru K, Yamagata H, Imaishi H. Metabolism of 7-ethoxycoumarin, safrole, flavanone and hydroxyflavanone by cytochrome P450 2A6 variants. Biopharm Drug Dispos 2012; 34:87-97. [DOI: 10.1002/bdd.1825] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 10/16/2012] [Accepted: 10/23/2012] [Indexed: 12/13/2022]
Affiliation(s)
- Tomohide Uno
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Yuichiro Obe
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Chika Ogura
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Tatsushi Goto
- Functional Analysis of Environmental Genes, Research Center for Environmental Genomics; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Kohei Yamamoto
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Masahiko Nakamura
- Department of Bioscience and Biotechnology, Faculty of Bioenvironmental Science; Kyoto Gakuen University; 1-1 Nanjo, Sogabe; Kameoka; Kyoto; 621-8555; Japan
| | - Kengo Kanamaru
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Hiroshi Yamagata
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| | - Hiromasa Imaishi
- Functional Analysis of Environmental Genes, Research Center for Environmental Genomics; Kobe University; Nada-ku; Kobe; Hyogo; 657-8501; Japan
| |
Collapse
|
33
|
Nakada T, Kiyotani K, Iwano S, Uno T, Yokohira M, Yamakawa K, Fujieda M, Saito T, Yamazaki H, Imaida K, Kamataki T. Lung tumorigenesis promoted by anti-apoptotic effects of cotinine, a nicotine metabolite through activation of PI3K/Akt pathway. J Toxicol Sci 2012; 37:555-63. [PMID: 22687995 DOI: 10.2131/jts.37.555] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We previously found that genetic polymorphism in cytochrome P450 2A6 (CYP2A6) is one of the potential determinants of tobacco-related lung cancer risk. It has been reported that the plasma concentration of cotinine, a major metabolite of nicotine, in carriers of wild-type alleles of CYP2A6 is considerably higher than that in carriers of null or reduced-function alleles of CYP2A6, raising the possibility that cotinine plays an important role in the development of lung cancer. As a novel mechanism of lung tumorigenesis mediated by CYP2A6, we investigated the effects of cotinine on the suppression of apoptosis and promotion of lung tumor growth. In human lung adenocarcinoma A549 cells, cotinine inhibited doxorubicin-induced cell death by suppressing caspase-mediated apoptosis. Enhanced phosphorylation of Akt, a key factor responsible for cell survival and inhibition of apoptosis, was detected after cotinine treatment. These data suggest that cotinine suppresses caspase-mediated apoptosis induced by doxorubicin through activation of the PI3K/Akt pathway. Furthermore, we clarified that cotinine significantly facilitated tumor growth in the Lewis lung cancer model and accelerated development of lung adenomas induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in A/J mice. We herein propose that cotinine induces tumor promotion by inhibiting apoptosis and enhancing cellular proliferation, thus underlining the importance of CYP2A6 in tobacco-related lung tumorigenesis.
Collapse
Affiliation(s)
- Tomohisa Nakada
- Laboratory of Drug Metabolism, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Williams JM, Gandhi KK, Lu SE, Steinberg ML, Benowitz NL. Nicotine intake and smoking topography in smokers with bipolar disorder. Bipolar Disord 2012; 14:618-27. [PMID: 22938167 PMCID: PMC3641517 DOI: 10.1111/j.1399-5618.2012.01047.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Cigarette smoking behavior in bipolar disorder (BPD), including the effects of mood-stabilizing medications, has not been well characterized. METHODS We compared serum nicotine, nicotine metabolite levels, and smoking topography in 75 smokers with BPD to 86 control smokers (CON). For some comparisons, an additional control group of 75 smokers with schizophrenia (SCZ) were included. RESULTS There were no differences between the BPD and CON groups in baseline smoking characteristics or serum nicotine or cotinine levels. Fifty-one smokers with BPD (68.9%) were taking one of the following mood stabilizers: valproic acid, lamotrigine, carbamazepine, oxcarbazepine, lithium, or topiramate. The 3-hydroxycotinine-to-cotinine ratio, a marker of cytochrome P450 2A6 (CYP2A6) metabolic activity, was significantly higher in BPD versus CON and versus SCZ (0.68 versus 0.49 versus 0.54; p =0.002). The difference between groups, however, was no longer significant when the analysis was repeated with those taking hepatic enzyme-inducing drugs (carbamazepine, oxcarbazepine, and topiramate) included as a covariate. The time between puffs, or interpuff interval (IPI), was shorter in BPD versus CON by an average of 3.0sec (p<0.05), although this was no longer significant when we removed smokers from the analysis of those taking hepatic enzyme inducers. CONCLUSIONS Smokers with BPD are not different from CON on most measures of nicotine intake and smoking topography. We found an increased rate of nicotine metabolism in smokers taking mood stabilizers that are hepatic enzyme inducers, including carbamazepine, oxcarbazepine, and topiramate. Smokers with rapid nicotine metabolism might be expected to smoke more intensely to compensate for the more rapid disappearance of nicotine from the blood and brain, and may have more difficulty in quitting smoking, although this requires further study.
Collapse
Affiliation(s)
- Jill M Williams
- University of Medicine and Dentistry of New Jersey (UMDNJ)-Robert Wood Johnson Medical School, New Brunswick, NJ 08901-2008, USA.
| | - Kunal K Gandhi
- UMDNJ–School of Public Health, New Brunswick, NJ,GlaxoSmithKline
| | - Shou-En Lu
- University of Medicine and Dentistry of New Jersey (UMDNJ)–Robert Wood Johnson Medical School, New Brunswick, NJ,UMDNJ–School of Public Health, New Brunswick, NJ
| | - Marc L Steinberg
- University of Medicine and Dentistry of New Jersey (UMDNJ)–Robert Wood Johnson Medical School, New Brunswick, NJ,UMDNJ–School of Public Health, New Brunswick, NJ
| | - Neal L Benowitz
- University of California at San Francisco, San Francisco, CA, USA
| |
Collapse
|
35
|
Han S, Choi S, Chun YJ, Yun CH, Lee CH, Shin HJ, Na HS, Chung MW, Kim D. Functional characterization of allelic variants of polymorphic human cytochrome P450 2A6 (CYP2A6*5, *7, *8, *18, *19, and *35). Biol Pharm Bull 2012; 35:394-9. [PMID: 22382327 DOI: 10.1248/bpb.35.394] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytochrome P450 2A6 (CYP2A6) catalyzes important metabolic reactions of many xenobiotic compounds, including coumarin, nicotine, cotinine, and clinical drugs. Genetic polymorphisms of CYP2A6 can influence its metabolic activities. This study analyzed the functional activities of six CYP2A6 allelic variants (CYP2A6*5, *7, *8, *18, *19, and *35) containing nonsynonymous single-nucleotide polymorphisms. Recombinant variant enzymes of CYP2A6*7, *8, *18, *19, and *35 were successfully expressed in Escherichia coli and purified. However, a P450 holoenzyme spectrum was not detected for the CYP2A6*5 allelic variant (G479V). Structural analysis shows that the G479V mutation may alter the interaction between the A helix and the F-G helices. Enzyme kinetic analyses indicated that the effects of mutations in CYP2A6 allelic variants on drug metabolism are dependent on the substrates. In the case of coumarin 7-hydroxylation, CYP2A6*8 and *35 displayed increased K(m) values whereas CYP2A6*18 and *19 showed decreased k(cat) values, which resulted in lower catalytic efficiencies (k(cat)/K(m)). In the case of nicotine 5-oxidation, the CYP2A6*19 variant exhibited an increased K(m) value, whereas CYP2A6*18 and *35 showed much greater decreases in k(cat) values. These results suggest that individuals carrying these allelic variants are likely to have different metabolisms for different CYP2A6 substrates. Functional characterization of these allelic variants of CYP2A6 can help determine the importance of CYP2A6 polymorphisms in the metabolism of many clinical drugs.
Collapse
Affiliation(s)
- Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Lee IS, Kim D. Polymorphic metabolism by functional alterations of human cytochrome P450 enzymes. Arch Pharm Res 2011; 34:1799-816. [PMID: 22139682 DOI: 10.1007/s12272-011-1103-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 08/24/2011] [Indexed: 10/14/2022]
Abstract
The study of cytochrome P450 pharmacogenomics is of particular interest because of its promise in the development of rational means to optimize drug therapy with respect to patient's genotype to ensure maximum efficacy with minimal adverse effects. Drug metabolizing P450 enzymes are polymorphic and are the main phase I enzymes responsible for the metabolism of clinical drugs. Therefore, polymorphisms in the P450s have the most impact on the fate of clinical drugs in phase I metabolism since almost 80% of drugs in use today are metabolized by these enzymes. Predictive genotyping for P450 enzymes for a more effective therapy will be routine for specific drugs in the future. In this review, we discuss the current knowledge of polymorphic metabolism by functional alterations in nonsynonymous SNPs of P450 1A2, 2A6, 2C8, 2C9, 2C19, 2D6, and 3A4 enzymes.
Collapse
Affiliation(s)
- Im-Soon Lee
- Department of Biological Sciences and Center for Biotechnology Research in UBITA, Konkuk University, Seoul 143-701, Korea
| | | |
Collapse
|
37
|
Wang H, Bian T, Liu D, Jin T, Chen Y, Lin A, Chen C. Association analysis of CYP2A6 genotypes and haplotypes with 5-fluorouracil formation from tegafur in human liver microsomes. Pharmacogenomics 2011; 12:481-92. [PMID: 21521021 DOI: 10.2217/pgs.10.202] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AIM Tegafur is primarily converted to 5-fluorouracil (5-FU) by CYP2A6 in the human liver to exert its antitumor effect. Our objective was to comprehensively investigate the effects of CYP2A6 genetic polymorphisms on tegafur bioactivation activity. MATERIALS & METHODS Using a set of over 45 Chinese livers, the association between CYP2A6 genetic variations and 5-FU formation rates from tegafur, as well as CYP2A6 mRNA and protein levels, was determined. RESULTS A total of 20 polymorphic variants and 20 haplotypes of CYP2A6 were identified. From genotype/haplotype-phenotype association tests, we demonstrated that CYP2A6*4 was the main allele responsible for the decreased 5-FU formation from tegafur and CYP2A6 expression in this population. By contrast, haplotype 14 (a novel CYP2A6*1B allele) was associated with increased microsomal 5-FU formation activity and CYP2A6 expression, and this may be attributed to the combined effects of three single variants (g.22C>T, g.1620T>C and a gene conversion in the 3´-UTR) included in this haplotype. CONCLUSION We concluded that CYP2A6*4 and the novel CYP2A6*1B variant were the major genetic determinants of interindividual variability in 5-FU formation from tegafur in Chinese livers. Original submitted 2 November 2010; Revision submitted 3 December 2010.
Collapse
Affiliation(s)
- Huijuan Wang
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an 710069, China
| | | | | | | | | | | | | |
Collapse
|
38
|
Liu T, David SP, Tyndale RF, Wang H, Zhou Q, Ding P, He YH, Yu XQ, Chen W, Crump C, Wen XZ, Chen WQ. Associations of CYP2A6 genotype with smoking behaviors in southern China. Addiction 2011; 106:985-94. [PMID: 21205058 PMCID: PMC3074015 DOI: 10.1111/j.1360-0443.2010.03353.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS To investigate the association of CYP2A6 genetic polymorphisms with smoking-related phenotypes in Chinese smokers. DESIGN Case-only genetic association study. SETTING Southern China. PARTICIPANTS A total of 1328 Han Chinese smokers who participated in a community-based chronic disease screening project in Guangzhou and Zhuhai from 2006 to 2007. MEASUREMENTS All participants answered a structured questionnaire about socio-demographic status and smoking behaviors and informative alleles were genotyped for the cytochrome P450 2A6 (CYP2A6) gene (CYP2A6*4,*5,*7,*9 and *10). FINDINGS The frequencies of CYP2A6*4, *5, *7, *9 and *10 alleles were 8.5, 1.2, 6.3, 13.5 and 2.4%, which corresponded to 48.9, 15.4, 24.2 and 11.5% of participants being classified as normal, intermediate, slow and poor metabolizers, respectively. Multivariate analyses in male smokers demonstrated that compared with normal metabolizers, poor metabolizers reported smoking fewer cigarettes per day [adjusted odds ratio (OR) = 0.49; 95% confidence interval (CI): 0.32-0.76], started smoking regularly later in life (adjusted OR = 1.55; 95% CI: 1.06-2.26) and, among former smokers, reported smoking for a shorter duration prior to quitting (adjusted OR = 0.33; 95% CI: 0.12-0.94). However, poor metabolizers were less likely to quit smoking and remain abstinent than normal metabolizers (adjusted OR = 0.54; 95% CI: 0.34-0.86). CONCLUSIONS Reduced metabolism function of cytochrome P450 2A6 in smokers appears to be associated with fewer cigarettes smoked, later initiation of smoking regularly, shorter smoking duration and lower likelihood of smoking cessation.
Collapse
Affiliation(s)
- Tao Liu
- Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-Sen University, 74, Zhongshan Road 2, 510080, Guangzhou, China
| | - Sean P. David
- Center for Education in Family & Community Medicine and the Division of Family & Community Medicine, Stanford University, 1215 Welch Road, Modular G, Stanford, CA 94305, USA, SRI International, 333 Ravenswood Ave, Menlo Park, CA 943025, USA, Center for Primary Care & Prevention and the Department of Family Medicine, Brown Alpert Medical School, 111 Brewster Street, Pawtucket, RI 02860
| | - Rachel F. Tyndale
- The Center for Addiction and Mental Health and the Departments of Psychiatry, Pharmacology and Toxicology, University of Toronto, Canada M5S 1A8
| | - Hui Wang
- Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-Sen University, 74, Zhongshan Road 2, 510080, Guangzhou, China
| | - Qian Zhou
- The Center for Addiction and Mental Health and the Departments of Psychiatry, Pharmacology and Toxicology, University of Toronto, Canada M5S 1A8
| | - Peng Ding
- Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-Sen University, 74, Zhongshan Road 2, 510080, Guangzhou, China
| | - Yan-Hui He
- Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-Sen University, 74, Zhongshan Road 2, 510080, Guangzhou, China
| | - Xue-Qing Yu
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-Sen University, 58, Zhongshan Road 2, 510080, Guangzhou, China
| | - Wei Chen
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-Sen University, 58, Zhongshan Road 2, 510080, Guangzhou, China
| | - Casey Crump
- Center for Education in Family & Community Medicine and the Division of Family & Community Medicine, Stanford University, 1215 Welch Road, Modular G, Stanford, CA 94305, USA
| | - Xiao-Zhong Wen
- Department of Community Health, Brown University, Providence, RI, USA
| | - Wei-Qing Chen
- Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-Sen University, 74, Zhongshan Road 2, 510080, Guangzhou, China,To whom correspondence should be addressed. Tel: +8620 87332199; Fax: +8620 87330446, (Wei-Qing Chen)
| |
Collapse
|
39
|
Tanii H, Shitara Y, Horie T. Population pharmacokinetic analysis of letrozole in Japanese postmenopausal women. Eur J Clin Pharmacol 2011; 67:1017-25. [PMID: 21494765 DOI: 10.1007/s00228-011-1042-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 03/21/2011] [Indexed: 12/21/2022]
Abstract
PURPOSE Letrozole is an orally active aromatase inhibitor for the treatment of breast cancer. The objectives of this study were to examine the pharmacokinetic profile of letrozole in Japanese subjects and to identify factors that influence variability in the pharmacokinetics of letrozole using population pharmacokinetic (PPK) analysis. METHODS Twenty-five healthy postmenopausal Japanese women were enrolled in the study and received 2.5 mg letrozole once daily for 14 or 28 days. A PPK model was developed using NONMEM software. Age, body weight (WT), AST, ALT, total bilirubin, serum creatinine (CRE), and genotype of CYP2A6 were studied as covariates. Estrone, estrone sulfate, and estradiol in plasma were measured as pharmacodynamic markers. RESULTS CYP2A6 genotype, CRE, and AST were significant covariates for apparent systemic clearance (CL/F), and WT was a significant covariate for apparent distribution volume (Vd/F). Population mean estimates of CL/F and Vd/F in subjects without CYP2A6 mutation were 1.03 × (CRE/0.70)(-1.27) × (AST/17.5)(-0.793) L/h and 94.2 × (WT/51.1)(1.12) L respectively. CL/F in subjects possessing 1 and 2 CYP2A6 mutation alleles were 84.3% and 44.8% of the value in the subjects without mutation respectively. Estrogen levels fell to below detection limits in most subjects after letrozole administration. Three mild and transient adverse events (upper respiratory tract inflammation, arthralgia, and vomiting) were reported in the study. CONCLUSIONS CYP2A6 genotype largely influences CL/F of letrozole. Genetic polymorphism of CYP2A6 and body weight will be causes of ethnic difference in PK. However, dose adjustment is not necessary, because of the wide therapeutic range.
Collapse
Affiliation(s)
- Hiromi Tanii
- Translational Science Department, Novartis Pharma K.K., 4-17-30, Nishiazabu, Minato-ku, Tokyo 106-8616, Japan.
| | | | | |
Collapse
|
40
|
Park SR, Kong SY, Nam BH, Choi IJ, Kim CG, Lee JY, Cho SJ, Kim YW, Ryu KW, Lee JH, Rhee J, Park YI, Kim NK. CYP2A6 and ERCC1 polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients. Br J Cancer 2011; 104:1126-34. [PMID: 21364592 PMCID: PMC3068488 DOI: 10.1038/bjc.2011.24] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Background: We evaluated the association between polymorphisms of cytochrome P450 2A6 (CYP2A6)/excision repair cross-complementation group 1 (ERCC1)/X-ray repair cross-complementing group 1(XRCC1) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin. Methods: Among MGC patients (n=108), who received S-1 (40 mg m−2 b.i.d., days 1–14) and cisplatin (60 mg m−2, day 1) every 3 weeks, we analysed the wild-type allele (W) and variants (V) of CYP2A6 (*4, *7, *9, *10), and the polymorphisms of ERCC1 (rs11615, rs3212986) and XRCC1 (rs25487). Results: Patients having fewer CYP2A6 variants had better response rates (W/W vs W/V other than *1/*4 vs V/V or *1/*4=66.7 vs 58.3 vs 32.3% P=0.008), time to progression (TTP) (7.2 vs 6.1 vs 3.5 months, P=0.021), and overall survival (23.2 vs 15.4 vs 12.0 months, P=0.004). ERCC1 19442C>A (rs3212986) was also associated with response rate (C/C, 46.7% vs C/A, 55.3% vs A/A, 87.5%) (P=0.048) and TTP (4.4 vs 7.6 vs 7.9 months) (P=0.012). Patients carrying both risk genotypes of CYP2A6 (V/V or 1/*4) and ERCC1 19442C>A (C/C) vs those carrying none showed an adjusted odds ratio of 0.113 (P=0.004) for response, and adjusted hazard ratios of 3.748 (P=0.0001) for TTP and 2.961 (P=0.006) for death. Conclusion: Polymorphisms of CYP2A6 and ERCC1 19442C>A correlated with the efficacy of S-1/cisplatin.
Collapse
Affiliation(s)
- S R Park
- Center for Gastric Cancer, Research Institute and Hospital, National Cancer Center, 111 Jungbalsan-ro, Ilsandong-gu, Goyang, Gyeonggi, 410-769, Republic of Korea.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Tsunoda A, Nakao K, Watanabe M, Matsui N, Ooyama A, Kusano M. Associations of various gene polymorphisms with toxicity in colorectal cancer patients receiving oral uracil and tegafur plus leucovorin: a prospective study. Ann Oncol 2010; 22:355-61. [PMID: 20647221 DOI: 10.1093/annonc/mdq358] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND To assess the predictive value of polymorphism in nine genes, primarily thymidylate synthase (TS) and orotate phosphoribosyltransferase (OPRT), which relates to 5-fluorouracil (5-FU) metabolism, for toxicity in patients treated with oral uracil/tegafur (UFT) plus leucovorin (LV). PATIENTS AND METHODS We treated 99 patients with stage II or III colorectal carcinoma with oral UFT + LV. Germline DNA from patients was genotyped for 5-FU and folate metabolism-relating genes. CYP2A6, tegafur-activating enzyme, and uridine diphosphate-glucuronosyltransferase 1A1 genetic variation were also assessed. Toxicity was graded by the National Cancer Institute Common Toxicity Criteria, version 2.0. RESULTS The multivariate logistic regression revealed that OPRT 638G>C polymorphism was associated with grade 3 diarrhea [odds ratio (OR) 19.84 for patients with the C/C homozygous type compared with patients with wild type, P = 0.014] and polymorphisms of UGT1A1 were associated with hyperbilirubinemia (OR 38.76 for homozygotes and double heterozygotes of *6 or *28 compared with wild type, P = 0.0008). No relationships were observed between TS polymorphisms and any toxicity. CONCLUSIONS OPRT polymorphism predicts toxicity, especially grade 3 or greater diarrhea to oral UFT + LV adjuvant chemotherapy, whereas TS does not, in our study cohort. UGT1A1 polymorphism seems to be a risk factor for hyperbilirubinemia due to UFT+LV.
Collapse
Affiliation(s)
- A Tsunoda
- Department of Surgery, Kameda Medical Center, Chiba.
| | | | | | | | | | | |
Collapse
|
42
|
Can the 2-(13)C-uracil breath test be used to predict the effect of the antitumor drug S-1? Cancer Chemother Pharmacol 2009; 66:333-43. [PMID: 19921195 DOI: 10.1007/s00280-009-1168-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Accepted: 10/27/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE S-1 is an oral anticancer drug containing tegafur (FT), a pro-drug of fluorouracil, combined with two modulators, 5-chloro-2,4-dihydroxypyridine and potassium oxonate (Oxo), at a molar ratio of 1:0.4:1. CYP2A6 genetic polymorphism and dihydropyrimidine dehydrogenase (DPD) inhibition are important for the antitumor effect of S-1. Exploiting the usefulness of the 2-(13)C-uracil breath test (UrBT) as an indicator of DPD activity, we examined whether the results of CYP2A6 genetic polymorphism analysis and UrBT could be used to predict the antitumor effect of S-1. METHODS Thirty-four patients with advanced or recurrent cancer (15, 16 and 3 with gastric, colorectal and pancreatic cancer, respectively) were orally administered 40 mg/m(2) S-1 twice daily in the morning and evening. Eighteen patients with a complete response (CR)/partial response (PR) (2 with CR, 16 with PR) and 16 with progressive disease (PD) were compared with respect to CYP2A6 genetic polymorphisms (1- vs. 2-allele mutation), UrBT results, and plasma FT and 5-fluorouracil levels at 3 h after S-1 ingestion in the morning. RESULTS On multivariate analysis between the CR/PR and PD groups, only the UrBT results was an independent factor of CR/PR to S-1 (95% CI 1.02-1.10). CONCLUSION These results suggest that the anticancer effect of S-1 can be predicted by performing UrBT 3 h after the initial oral S-1 administration.
Collapse
|
43
|
Murai K, Yamazaki H, Nakagawa K, Kawai R, Kamataki T. Deactivation of anti-cancer drug letrozole to a carbinol metabolite by polymorphic cytochrome P450 2A6 in human liver microsomes. Xenobiotica 2009; 39:795-802. [DOI: 10.3109/00498250903171395] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
44
|
Zhou SF, Liu JP, Chowbay B. Polymorphism of human cytochrome P450 enzymes and its clinical impact. Drug Metab Rev 2009; 41:89-295. [PMID: 19514967 DOI: 10.1080/03602530902843483] [Citation(s) in RCA: 502] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pharmacogenetics is the study of how interindividual variations in the DNA sequence of specific genes affect drug response. This article highlights current pharmacogenetic knowledge on important human drug-metabolizing cytochrome P450s (CYPs) to understand the large interindividual variability in drug clearance and responses in clinical practice. The human CYP superfamily contains 57 functional genes and 58 pseudogenes, with members of the 1, 2, and 3 families playing an important role in the metabolism of therapeutic drugs, other xenobiotics, and some endogenous compounds. Polymorphisms in the CYP family may have had the most impact on the fate of therapeutic drugs. CYP2D6, 2C19, and 2C9 polymorphisms account for the most frequent variations in phase I metabolism of drugs, since almost 80% of drugs in use today are metabolized by these enzymes. Approximately 5-14% of Caucasians, 0-5% Africans, and 0-1% of Asians lack CYP2D6 activity, and these individuals are known as poor metabolizers. CYP2C9 is another clinically significant enzyme that demonstrates multiple genetic variants with a potentially functional impact on the efficacy and adverse effects of drugs that are mainly eliminated by this enzyme. Studies into the CYP2C9 polymorphism have highlighted the importance of the CYP2C9*2 and *3 alleles. Extensive polymorphism also occurs in other CYP genes, such as CYP1A1, 2A6, 2A13, 2C8, 3A4, and 3A5. Since several of these CYPs (e.g., CYP1A1 and 1A2) play a role in the bioactivation of many procarcinogens, polymorphisms of these enzymes may contribute to the variable susceptibility to carcinogenesis. The distribution of the common variant alleles of CYP genes varies among different ethnic populations. Pharmacogenetics has the potential to achieve optimal quality use of medicines, and to improve the efficacy and safety of both prospective and currently available drugs. Further studies are warranted to explore the gene-dose, gene-concentration, and gene-response relationships for these important drug-metabolizing CYPs.
Collapse
Affiliation(s)
- Shu-Feng Zhou
- School of Health Sciences, RMIT University, Bundoora, Victoria, Australia.
| | | | | |
Collapse
|
45
|
Koudsi NA, Ahluwalia JS, Lin SK, Sellers EM, Tyndale RF. A novel CYP2A6 allele (CYP2A6*35) resulting in an amino-acid substitution (Asn438Tyr) is associated with lower CYP2A6 activity in vivo. THE PHARMACOGENOMICS JOURNAL 2009; 9:274-82. [PMID: 19365400 PMCID: PMC2922203 DOI: 10.1038/tpj.2009.11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 02/11/2009] [Accepted: 03/16/2009] [Indexed: 11/09/2022]
Abstract
Cytochrome P450 2A6 (CYP2A6) is the primary human enzyme involved in nicotine metabolism. The objective of this study was to characterize two nonsynonymous single nucleotide polymorphisms in CYP2A6(*)24, 594G>C (Val110Leu) and 6458A>T (Asn438Tyr). We determined their haplotype, allele frequencies, effect on CYP2A6 activity in vivo, as well as their stability and ability to metabolize nicotine in vitro. CYP2A6(*)35 (6458A>T) occurred at a frequency of 2.5-2.9% among individuals of black African descent, 0.5-0.8% among Asians and was not found in Caucasians. In addition, we identified two novel alleles, CYP2A6(*)36 (6458A>T and 6558T>C (Ile471Thr)) and CYP2A6(*)37 (6458A>T, 6558T>C and 6600G>T (Arg485Leu)). In vivo, CYP2A6(*)35 was associated with lower CYP2A6 activity as measured by the 3HC/COT ratio. In vitro, CYP2A6.35 had decreased nicotine C-oxidation activity and thermal stability. In conclusion, we identified three novel CYP2A6 alleles (CYP2A6(*)35, (*)36 and (*)37); the higher allele frequency variant CYP2A6(*)35 was associated with lower CYP2A6 activity.
Collapse
Affiliation(s)
- Nael Al Koudsi
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Jasjit S. Ahluwalia
- Department of Medicine and Masonic Cancer Centre, University of Minnesota, Minneapolis, MN
| | - Shih-Ku Lin
- Taipei City Hospital and Psychiatric Centre, Taipei, Taiwan
| | - Edward M. Sellers
- Clinical Pharmacology, Kendle Early Phase, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Rachel F. Tyndale
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| |
Collapse
|
46
|
Yusof W, Gan SH. High prevalence of CYP2A6⁎4 and CYP2A6⁎9 alleles detected among a Malaysian population. Clin Chim Acta 2009; 403:105-9. [DOI: 10.1016/j.cca.2009.01.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 01/28/2009] [Accepted: 01/28/2009] [Indexed: 10/21/2022]
|
47
|
Abstract
The molecular genetics of nicotine metabolism involves multiple polymorphic catalytic enzymes. Variation in metabolic pathways results in nicotine disposition kinetics that differ between individuals and ethnic groups. Twin studies indicate that a large part of this variance is genetic in origin, although environmental influences also contribute. The primary aim of this chapter is to review the current knowledge regarding the genetic variability in the enzymes that metabolize nicotine in humans. The focus is on describing the genetic polymorphisms that exist in cytochromes P450 (CYPs), aldehyde oxidase 1 (AOX1), UDP-glucuronosyltransferases (UGTs), and flavin-containing monooxygenase 3 (FMO3). Genetic studies have demonstrated that polymorphisms in CYP2A6, the primary enzyme responsible for nicotine breakdown, make a sizable contribution to the wide range of nicotine metabolic capacity observed in humans. Thus, special attention will be given to CYP2A6, because slower nicotine metabolism requires less frequent self-administration, and accordingly influences smoking behaviors. In addition, the molecular genetics of nicotine metabolism in nonhuman primates, mice, and rats will be reviewed briefly.
Collapse
Affiliation(s)
- Jill C Mwenifumbo
- Centre for Addiction & Mental Health and Department of Pharmacology, University of Toronto, Toronto, ON, Canada
| | | |
Collapse
|
48
|
Mwenifumbo JC, Sellers EM, Tyndale RF. Socioeconomic and drug use determinants of smoking status in an urban adult population of Black African descent. Nicotine Tob Res 2009; 10:1319-25. [PMID: 18686179 DOI: 10.1080/14622200802238894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We examined the influence of socioeconomics and drug use on current smokers (N = 137) and nonsmokers (N = 143) from an urban adult population of Black African descent. Median participant age was 33 years (range = 20-59). Smokers consumed a median of eight cigarettes/day (range = 0-35). Interestingly, 86% smoked fewer than 15 cigarettes/day and only 8% smoked menthol cigarettes. Socioeconomic and drug use variables significantly associated with smoking status in univariate analyses were included in a multiple logistic regression model that controlled for gender and age. Compared with nonsmokers, smokers were less likely to be university educated, more likely to be divorced, separated, or widowed, more likely to be current alcohol users, and more likely to be current marijuana users. Unexpectedly, household income and employment status were not associated with smoking status. Among current alcohol users, smokers consumed three times the number of drinks per month that nonsmokers consumed (p<.001). Among current marijuana users, smokers consumed more than five times the number of joints per month that nonsmokers consumed (p<.001). Overall, lower education levels, divorce, and alcohol and marijuana use were significantly associated with increased likelihood of smoking among this population.
Collapse
Affiliation(s)
- Jill C Mwenifumbo
- The Centre for Addiction and Mental Health and Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada
| | | | | |
Collapse
|
49
|
CYP2A6 genotypes and coumarin-oxidation phenotypes in a Thai population and their relationship to tobacco smoking. Eur J Clin Pharmacol 2008; 65:377-84. [DOI: 10.1007/s00228-008-0595-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2008] [Accepted: 11/18/2008] [Indexed: 10/21/2022]
|
50
|
Rossini A, de Almeida Simão T, Albano RM, Pinto LFR. CYP2A6 polymorphisms and risk for tobacco-related cancers. Pharmacogenomics 2008; 9:1737-52. [PMID: 19018727 DOI: 10.2217/14622416.9.11.1737] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tobacco consumption is the main identifiable risk to cancer, contributing to the majority of tumors in upper aerodigestive tissues. The psychoactive compound responsible for tobacco addiction, nicotine and the potent carcinogens present at high concentrations either in cigarette mainstream smoke or in smokeless tobacco products, 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK) and N-nitrosonornicotine (NNN) can be metabolized by CYP2A6. CYP2A6 is expressed in many aerodigestive tissues with high interindividual variability. The CYP2A6 gene is highly polymorphic and CYP2A6 alleles coding for enzymes with altered expression or metabolic capacity produce alterations in nicotine metabolism in vivo and seem to influence smoking behavior. These polymorphisms may change the rate of NNK and NNN activation and, therefore, may influence cancer risk associated with tobacco consumption. However, to date only a few and inconclusive studies have addressed the risk that a given CYP2A6 polymorphism presents for the development of tobacco-related tumors. Most, but not all, show a reduced risk associated with alleles that result in decreased enzyme activity. The overlapping substrate specificity and tissue expression between CYP2A6 and the highly similar CYP2A13 may add to the conflicting results observed. The intricate regulation of CYP2A6 and the variation of structurally different chemical compounds capable of inhibiting CYP2A enzymes also add to the complexity. Finally, the interaction between polymorphisms of genes that code for CYP2A6, CYP2A13 and other potent carcinogen-metabolizing CYP enzymes may help to determine individuals that are at higher risk of developing tumors associated with tobacco consumption.
Collapse
Affiliation(s)
- Ana Rossini
- Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Departamento de Bioquímica Brazil, Rio de Janeiro, Brazil
| | | | | | | |
Collapse
|