1
|
Abad-Santos F, Aliño SF, Borobia AM, García-Martín E, Gassó P, Maroñas O, Agúndez JAG. Developments in pharmacogenetics, pharmacogenomics, and personalized medicine. Pharmacol Res 2024; 200:107061. [PMID: 38199278 DOI: 10.1016/j.phrs.2024.107061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/13/2023] [Accepted: 01/04/2024] [Indexed: 01/12/2024]
Abstract
The development of Pharmacogenetics and Pharmacogenomics in Western Europe is highly relevant in the worldwide scenario. Despite the usually low institutional support, many research groups, composed of basic and clinical researchers, have been actively working for decades in this field. Their contributions made an international impact and paved the way for further studies and pharmacogenomics implementation in clinical practice. In this manuscript, that makes part of the Special Issue entitled Spanish Pharmacology, we present an analysis of the state of the art of Pharmacogenetics and Pharmacogenomics research in Europe, we compare it with the developments in Spain, and we summarize the most salient contributions since 1988 to the present, as well as recent developments in the clinical application of pharmacogenomics knowledge. Finally, we present some considerations on how we could improve translation to clinical practice in this specific scenario.
Collapse
Affiliation(s)
- Francisco Abad-Santos
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), CIBEREHD, Instituto de Investigación Sanitaria La Princesa (IP), Madrid, Spain.
| | - Salvador F Aliño
- Gene Therapy and Pharmacogenomics Group, Department of Pharmacology, Faculty of Medicine, Universitat de València, Av. Blasco Ibáñez 15, 46010 Valencia, Spain
| | - Alberto M Borobia
- Clinical Pharmacology Department, La Paz University Hospital, School of Medicine, Universidad Autónoma de Madrid (UAM), IdiPAZ, Madrid, Spain
| | - Elena García-Martín
- Department of Pharmacology, Universidad de Extremadura, Avda de la Universidad s/n, 10071 Cáceres, Spain
| | - Patricia Gassó
- Basic Clinical Practice Department, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona Clínic Schizophrenia Unit (BCSU), IDIBAPS, CIBERSAM, Barcelona, Spain
| | - Olalla Maroñas
- Public Foundation of Genomic Medicine, Santiago University Hospital, Genomic Medicine group, Pharmacogenetics and Drug Discovery (GenDeM), CIBERER, Santiago Health Research Institute (IDIS), Galicia, Spain
| | - José A G Agúndez
- Universidad de Extremadura. University Institute of Molecular Pathology Biomarkers, Avda de las Ciencias s/n, 10071 Cáceres, Spain.
| |
Collapse
|
2
|
Sasaki GY, Vodovotz Y, Yu Z, Bruno RS. Catechin Bioavailability Following Consumption of a Green Tea Extract Confection Is Reduced in Obese Persons without Affecting Gut Microbial-Derived Valerolactones. Antioxidants (Basel) 2022; 11:antiox11122490. [PMID: 36552698 PMCID: PMC9774199 DOI: 10.3390/antiox11122490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Obesity-related cardiometabolic disorders are driven by inflammation, oxidative stress, and gut dysbiosis. Green tea catechins protect against cardiometabolic disorders by anti-inflammatory, antioxidant, and prebiotic activities. However, whether obesity alters catechin bioavailability remains unknown. We hypothesized that obesity would decrease catechin bioavailability due to altered gut microbiota composition. Obese and healthy persons completed a pharmacokinetics trial in which a confection formulated with green tea extract (GTE; 58% epigallocatechin gallate, 17% epigallocatechin, 8% epicatechin, 6% epicatechin gallate) was ingested before collecting plasma and urine at timed intervals for up to 24 h. Stool samples were collected prior to confection ingestion. Catechins and γ-valerolactones were assessed by LC-MS. Obesity reduced plasma area under the curve (AUC0-12h) by 24-27% and maximum plasma concentrations by 18-36% for all catechins. Plasma AUC0-12h for 5'-(3',4'-dihydroxyphenyl)-γ-valerolactone and 5'-(3',4',5'-trihydroxyphenyl)-γ-valerolactone, as well as total urinary elimination of all catechins and valerolactones, were unaffected. ⍺-Diversity in obese persons was lower, while Slackia was the only catechin-metabolizing bacteria that was altered by obesity. Ascorbic acid and diversity metrics were correlated with catechin/valerolactone bioavailability. These findings indicate that obesity reduces catechin bioavailability without affecting valerolactone generation, urinary catechin elimination, or substantially altered gut microbiota populations, suggesting a gut-level mechanism that limits catechin absorption.
Collapse
Affiliation(s)
- Geoffrey Y. Sasaki
- Human Nutrition Program, The Ohio State University, Columbus, OH 43210, USA
| | - Yael Vodovotz
- Department of Food Science and Technology, The Ohio State University, Columbus, OH 43210, USA
| | - Zhongtang Yu
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Richard S. Bruno
- Human Nutrition Program, The Ohio State University, Columbus, OH 43210, USA
- Correspondence: ; Tel.: +1-614-292-5522
| |
Collapse
|
3
|
Man vs. machine: comparison of pharmacogenetic expert counselling with a clinical medication support system in a study with 200 genotyped patients. Eur J Clin Pharmacol 2021; 78:579-587. [PMID: 34958399 PMCID: PMC8926977 DOI: 10.1007/s00228-021-03254-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 11/16/2021] [Indexed: 11/24/2022]
Abstract
Background Medication problems such as strong side effects or inefficacy occur frequently. At our university hospital, a consultation group of specialists takes care of patients suffering from medication problems. Nevertheless, the counselling of poly-treated patients is complex, as it requires the consideration of a large network of interactions between drugs and their targets, their metabolizing enzymes, and their transporters, etc. Purpose This study aims to check whether a score-based decision-support system (1) reduces the time and effort and (2) suggests solutions at the same quality level. Patients and methods A total of 200 multimorbid, poly-treated patients with medication problems were included. All patients were considered twice: manually, as clinically established, and using the Drug-PIN decision-support system. Besides diagnoses, lab data (kidney, liver), phenotype (age, gender, BMI, habits), and genotype (genetic variants with actionable clinical evidence I or IIa) were considered, to eliminate potentially inappropriate medications and to select individually favourable drugs from existing medication classes. The algorithm is connected to automatically updated knowledge resources to provide reproducible up-to-date decision support. Results The average turnaround time for manual poly-therapy counselling per patient ranges from 3 to 6 working hours, while it can be reduced to ten minutes using Drug-PIN. At the same time, the results of the novel computerized approach coincide with the manual approach at a level of > 90%. The holistic medication score can be used to find favourable drugs within a class of drugs and also to judge the severity of medication problems, to identify critical cases early and automatically. Conclusion With the computerized version of this approach, it became possible to score all combinations of all alternative drugs from each class of drugs administered (“personalized medication landscape “) and to identify critical patients even before problems are reported (“medication alert”). Careful comparison of manual and score-based results shows that the incomplete manual consideration of genetic specialties and pharmacokinetic conflicts is responsible for most of the (minor) deviations between the two approaches. The meaning of the reduction of working time for experts by about 2 orders of magnitude should not be underestimated, as it enables practical application of personalized medicine in clinical routine.
Collapse
|
4
|
Lin YS, Thummel KE, Thompson BD, Totah RA, Cho CW. Sources of Interindividual Variability. Methods Mol Biol 2021; 2342:481-550. [PMID: 34272705 DOI: 10.1007/978-1-0716-1554-6_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The efficacy, safety, and tolerability of drugs are dependent on numerous factors that influence their disposition. A dose that is efficacious and safe for one individual may result in sub-therapeutic or toxic blood concentrations in others. A significant source of this variability in drug response is drug metabolism, where differences in presystemic and systemic biotransformation efficiency result in variable degrees of systemic exposure (e.g., AUC, Cmax, and/or Cmin) following administration of a fixed dose.Interindividual differences in drug biotransformation have been studied extensively. It is recognized that both intrinsic factors (e.g., genetics, age, sex, and disease states) and extrinsic factors (e.g., diet , chemical exposures from the environment, and the microbiome) play a significant role. For drug-metabolizing enzymes, genetic variation can result in the complete absence or enhanced expression of a functional enzyme. In addition, upregulation and downregulation of gene expression, in response to an altered cellular environment, can achieve the same range of metabolic function (phenotype), but often in a less predictable and time-dependent manner. Understanding the mechanistic basis for variability in drug disposition and response is essential if we are to move beyond the era of empirical, trial-and-error dose selection and into an age of personalized medicine that will improve outcomes in maintaining health and treating disease.
Collapse
Affiliation(s)
- Yvonne S Lin
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA.
| | - Kenneth E Thummel
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Brice D Thompson
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Rheem A Totah
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Christi W Cho
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| |
Collapse
|
5
|
Khalaj Z, Baratieh Z, Nikpour P, Schwab M, Schaeffeler E, Mokarian F, Khanahmad H, Salehi R, Mürdter TE, Salehi M. Clinical Trial: CYP2D6 Related Dose Escalation of Tamoxifen in Breast Cancer Patients With Iranian Ethnic Background Resulted in Increased Concentrations of Tamoxifen and Its Metabolites. Front Pharmacol 2019; 10:530. [PMID: 31178724 PMCID: PMC6543868 DOI: 10.3389/fphar.2019.00530] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 04/26/2019] [Indexed: 12/30/2022] Open
Abstract
Introduction: The polymorphic enzyme cytochrome P450 2D6 (CYP2D6) catalyzes a major step in the bioactivation of tamoxifen. Genotyping of clinically relevant CYP2D6 alleles and subsequent dose adjustment is a promising approach to individualize breast cancer therapy. The aim of this study was to investigate the relationship between the plasma levels of tamoxifen and its metabolites and different CYP2D6 genotypes under standard (20 mg/day) and dose-adjusted therapy (Registration ID in Iranian Registry of Clinical Trials: IRCT2015082323734N1). Materials and Methods: Using TaqMan® assays common alleles of CYP2D6 (∗1, ∗2, ∗4, ∗5, ∗6, ∗10, ∗17, and ∗41) and gene duplication were identified in 134 breast cancer patients. Based on CYP2D6 genotypes patients with an activity score 1 (n = 15) and 0-0.5 (n = 2) were treated with tamoxifen adjusted dosage of 30 and 40 mg/day, respectively. The concentration of tamoxifen and its metabolites before and after 4 and 8 months of dose adjustment were measured using LC-MS/MS technology. Results: At baseline, (Z)-endoxifen plasma concentrations (33 ± 15.5, 28.1 ± 14, 26.6 ± 23.4, 14.3 ± 8.6, and 10.7 ± 5.5 nmol/l for EM/EM, EM/IM, EM/PM, IM/IM and PM/PM, respectively) and the metabolic ratio (Z)-Endoxifen/N-desmethyltamoxifen (0.0558 ± 0.02, 0.0396 ± 0.0111, 0.0332 ± 0.0222, 0.0149 ± 0.0026, and 0.0169 ± 0.0177 for EM/EM, EM/IM, EM/PM, IM/IM, and PM/PM, respectively) correlated with CYP2D6 genotype (Kruskal-Wallis p = 0.013 and p < 0.0001, respectively). Dose escalation to 30 and 40 mg/day in patients with a CYP2D6 activity score of 1 (n = 15) and 0-0.5 (n = 2) resulted in a significant increase in (Z)-endoxifen plasma levels (22.17 ± 24.42, 34.43 ± 26.54, and 35.77 ± 28.89 nmol/l at baseline, after 4 and 8 months, respectively, Friedman p = 0.0388) along with the plasma concentrations of tamoxifen and its other metabolites. No severe side effects were recorded during dose escalation. Conclusion: For the first time, we show the feasibility of dose escalation of tamoxifen in breast cancer patients with compromised CYP2D6 activity and Iranian ethnic background to increase the plasma concentrations of (Z)-endoxifen.
Collapse
Affiliation(s)
- Zahra Khalaj
- Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Zohreh Baratieh
- Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parvaneh Nikpour
- Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany.,Department of Clinical Pharmacology, University Hospital Tübingen, Tübingen, Germany.,Department of Pharmacy and Biochemistry, University Hospital Tübingen, Tübingen, Germany
| | - Elke Schaeffeler
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany.,University of Tübingen, Tübingen, Germany
| | - Fariborz Mokarian
- Cancer Prevention Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hossein Khanahmad
- Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Rasoul Salehi
- Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Thomas E Mürdter
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany.,University of Tübingen, Tübingen, Germany
| | - Mansoor Salehi
- Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.,Cellular, Molecular and Genetics Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
6
|
Peters FT, Steuer AE. Antemortem and postmortem influences on drug concentrations and metabolite patterns in postmortem specimens. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/wfs2.1297] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Frank T. Peters
- Institute of Forensic Medicine Jena University Hospital Jena Germany
| | - Andrea E. Steuer
- Department of Forensic Pharmacology and Toxicology, Zurich Institute of Forensic Medicine University of Zurich Zurich Switzerland
| |
Collapse
|
7
|
Advanced Approaches to Model Xenobiotic Metabolism in Bacterial Genotoxicology In Vitro. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017. [PMID: 27619490 DOI: 10.1007/10_2016_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
During the past 30 years there has been considerable progress in the development of bacterial test systems for use in genotoxicity testing by the stable introduction of expression vectors (cDNAs) coding for xenobiotic-metabolizing enzymes into bacterial cells. The development not only provides insights into the mechanisms of bioactivation of xenobiotic compounds but also evaluates the roles of enzymes involved in metabolic activation or inactivation in chemical carcinogenesis. This review describes recent advances in bacterial genotoxicity assays and their future prospects, with a focus on the development and application of genetically engineering bacterial cells to incorporate some of the enzymatic activities involved in the bio-activation process of xenobiotics. Various genes have been introduced into bacterial umu tester strains encoding enzymes for genotoxic bioactivation, including bacterial nitroreductase and O-acetyltransferase, human cytochrome P450 monooxygenases, rat glutathione S-transferases, and human N-acetyltransferases and sulfotransferases. Their application has provided new tools for genotoxicity assays and for studying the role of biotransformation in chemical carcinogenesis in humans.
Collapse
|
8
|
Oda Y. Development and progress for three decades in umu test systems. Genes Environ 2016; 38:24. [PMID: 27980699 PMCID: PMC5131509 DOI: 10.1186/s41021-016-0054-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 07/27/2016] [Indexed: 11/10/2022] Open
Abstract
Umu test have been widely used to predict the detection and assessment of DNA- damaging chemicals in environmental genotoxicity field for three decades. This test system is more useful with respect to simplicity, sensitivity, rapidity, and reproducibility. A review of the literature on the development of the umu test is presented in this article. The contents of this article are included a description of numerous data using the umu test. This test have been fully evaluated and used in many directions. Different genetically engineered umu systems introducing bacterial and rat or human drug metabolizing enzymes into the umu tester strains, have been successfully established and are considered as useful tools for genotoxicity assays to study the mechanisms of biotransformation in chemical carcinogenesis. Actually, we developed that two types of bacterial metabolizing enzymes and 4 types of rat and human metabolizing enzyme DNAs are expressed in these strains such as nitroreductase and O-acetyltransferase, cytochrome P450, N-acetyltransferases, sulfotransferases, and glutathione S-transferases, respectively. Due to increasing numbers of minute environmental samples and new pharmaceuticals, a high-throughput umu test system using Salmonella typhimurium TA1535/pSK1002, NM2009, and NM3009 strains provides a useful for these genotoxicity screening. I also briefly describe the first attempts to incorporate such umu tester strain into photo-genotoxicity test.
Collapse
Affiliation(s)
- Yoshimitsu Oda
- Institute of Life and Environmental Sciences, Osaka Shin-Ai College, 6-2-28 Tsurumi, Tsurumi-ku, Osaka 538-0053 Japan
| |
Collapse
|
9
|
Amal Al Omari, Murry DJ. Pharmacogenetics of the Cytochrome P450 Enzyme System: Review of Current Knowledge and Clinical Significance. J Pharm Pract 2016. [DOI: 10.1177/0897190007304821] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Genetic variation in drug metabolizing enzymes is an important contributor to interindividual variation in drug disposition and response and is associated with significant clinical consequences. Many commonly used drugs are dependent on the cytochrome P450 monooxygenase enzymes (CYP450) for their metabolism and elimination. At present, more than 57 active human CYP450 genes are known, and the majority of these genes are polymorphic. Despite the large number of CYP450 genes, only the CYP1, CYP2, and CYP3 families of enzymes have a major role in drug metabolism. Approximately 10 CYP450s are responsible for the metabolism of a large number of pharmacologic agents in human beings. The polymorphic forms of the CYP450s are responsible for the development of a significant number of adverse drug reactions and may also contribute to drug response. Genetic polymorphisms have now been identified in the genes encoding all the main CYP450s that contribute to drug and other xenobiotic metabolism, and there are marked interethnic differences in the distribution and frequency of variant alleles. A review of the progress in the pharmacogenetics of P450s that are important for drug metabolism is presented with particular emphasis on the clinical relevance of this research.
Collapse
Affiliation(s)
- Amal Al Omari
- Department of Clinical and Administrative Pharmacy at the University of Iowa
| | - Daryl J. Murry
- Department of Clinical and Administrative Pharmacy, College of Pharmacy, S418 Phar, University of Iowa, 115 S. Grand Ave, Iowa City, IA 52242,
| |
Collapse
|
10
|
Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Agúndez JAG. NAT2 polymorphisms and risk for Parkinson's disease: a systematic review and meta-analysis. Expert Opin Drug Metab Toxicol 2016; 12:937-46. [PMID: 27216438 DOI: 10.1080/17425255.2016.1192127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Several studies suggested a possible association between certain polymorphisms in the N-acetyl-transferase 2 (NAT2) gene (which encodes a very important enzyme involved in xenobiotic metabolism) and the risk for Parkinson's disease (PD). As the results of studies on this issue are controversial, we conducted a systematic review and a meta-analysis of eligible studies on this putative association. AREAS COVERED The authors revised the relationship between NAT2 polymorphisms and the risk of developing PD using several databases, and performed a meta-analysis using the software Meta-Disc1.1.1. In addition heterogeneity between studies was analyzed. A description of studies regarding gene-gene interactions and gene-environmental interactions involving NAT2 polymorphisms is also made. EXPERT OPINION Despite several recent meta-analyses showing an association between several polymorphisms in genes related with detoxification mechanisms such as cytochrome P4502D6 (CYP2D6), and glutathione transferases M1 and T1 (GSTM1, and GSTT1), data on NAT2 gene polymorphisms obtained from the current meta-analysis do not support a major association with PD risk, except in Asian populations. However, data from many studies are incomplete and therefore insufficient data exists to draw definitive conclusions. Several studies suggesting gene-gene and gene-environmental factors involving NAT2 gene in PD risk await confirmation.
Collapse
Affiliation(s)
- Félix Javier Jiménez-Jiménez
- a Section of Neurology , Hospital Universitario del Sureste , Arganda del Rey , Madrid , Spain.,b Department of Medicine-Neurology, Hospital 'Príncipe de Asturias' , Universidad de Alcalá , Alcalá de Henares , Madrid , Spain
| | | | | | - José A G Agúndez
- c Department of Pharmacology , University of Extremadura , Cáceres , Spain
| |
Collapse
|
11
|
Identification and utilization of donor and recipient genetic variants to predict survival after HCT: are we ready for primetime? Curr Hematol Malig Rep 2015; 10:45-58. [PMID: 25700678 PMCID: PMC4352187 DOI: 10.1007/s11899-014-0246-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Overall survival following hematopoietic cell transplantation (HCT) has improved over the past two decades through better patient selection and advances in HLA typing, supportive care, and infection prophylaxis. Nonetheless, mortality rates are still unsatisfactory and transplant-related mortality remains a major cause of death after unrelated allogeneic HCT. Since there are no known pre-HCT, non-HLA biologic predictors of survival following transplant, for over a decade, scientists have been investigating the role of non-HLA germline genetic variation in survival and treatment-related mortality after HCT. Variation in single nucleotide polymorphisms (SNPs) has the potential to impact chemotherapy, radiation, and immune responses, leading to different post-HCT survival outcomes. In this paper, we address the current knowledge of the contribution of genetic variation to survival following HCT and discuss study design and methodology for investigating HCT survival on a genomic scale.
Collapse
|
12
|
Mach J, Huizer-Pajkos A, Mitchell SJ, McKenzie C, Phillips L, Kane A, Jones B, de Cabo R, Cogger V, Le Couteur DG, Hilmer SN. The effect of ageing on isoniazid pharmacokinetics and hepatotoxicity in Fischer 344 rats. Fundam Clin Pharmacol 2015; 30:23-34. [PMID: 26454000 DOI: 10.1111/fcp.12157] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/20/2015] [Accepted: 10/06/2015] [Indexed: 01/09/2023]
Abstract
Isoniazid is the first-line treatment for tuberculosis; however, its use is limited by hepatotoxicity. Age-related differences in isoniazid pharmacokinetics and hepatotoxicity are uncertain. We aimed to investigate these in young (3 ± 0 months, n = 26) and old (23.0 ± 0.2 months, n = 27) male Fischer 344 rats following a low- or high-dose toxic regimen of isoniazid or vehicle (4 doses/day over 2 days; low: 100, 75, 75, 75 mg/kg; high: 150, 105, 105, 105 mg/kg i.p. every 3 h). Fifteen hours after the last dose, animals were euthanized and sera and livers were prepared for analysis. Isoniazid treatment increased serum hepatotoxicity markers (alanine and aspartate transaminase) in young animals but not in old animals, and only reached significance with the high dose in young animals. Isoniazid treatment caused a trend towards an increase in necrosis in young animals with both doses. In contrast, microvesicular steatosis was increased in old isoniazid-treated animals, reaching significance only with the low dose (steatosis prevalence in old: vehicle 1/9, isoniazid 4/5; P < 0.05). Among isoniazid-treated animals, concentrations of toxic intermediates acetylhydrazine and hydrazine were higher in old than young animals (P < 0.05). With both doses, hepatic cytochrome P450 2E1 activity was higher in young animals compared with old (P < 0.05). There were no other age effects seen on any of the other measured enzymes involved in isoniazid metabolism (N-acetyl transferase, amidase, glutathione-S-transferase). These results show age-related changes in isoniazid pharmacokinetics may contribute towards differential patterns of toxicity and confirm that standard hepatotoxicity markers do not detect isoniazid-induced microvesicular steatosis.
Collapse
Affiliation(s)
- John Mach
- Laboratory of Ageing and Pharmacology, Kolling Institute of Medical Research, Sydney, NSW, Australia.,Department of Clin Pharmacol and Aged Care, Royal North Shore Hosp, Sydney, NSW, Australia.,Sydney Medical School, Univ of Sydney, Sydney, NSW, Australia
| | - Aniko Huizer-Pajkos
- Laboratory of Ageing and Pharmacology, Kolling Institute of Medical Research, Sydney, NSW, Australia.,Department of Clin Pharmacol and Aged Care, Royal North Shore Hosp, Sydney, NSW, Australia
| | - Sarah J Mitchell
- Translational Gerontology Branch, National Institute on Aging, National Institute of Health, Baltimore, Maryland, USA
| | - Catriona McKenzie
- Pathology Department, Royal Prince Alfred Hosp, Sydney, NSW, Australia
| | - Leo Phillips
- Mass Spec Imaging and Proteomics Laboratory, Kolling institute of Medical Research, Sydney, NSW, Australia
| | - Alice Kane
- Laboratory of Ageing and Pharmacology, Kolling Institute of Medical Research, Sydney, NSW, Australia.,Department of Clin Pharmacol and Aged Care, Royal North Shore Hosp, Sydney, NSW, Australia.,Sydney Medical School, Univ of Sydney, Sydney, NSW, Australia
| | - Brett Jones
- Sydney Medical School, Univ of Sydney, Sydney, NSW, Australia.,Department of Gastroenterology, Kolling Institute of Medical Research, Sydney, NSW, Australia
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, National Institute of Health, Baltimore, Maryland, USA
| | - Victoria Cogger
- Sydney Medical School, Univ of Sydney, Sydney, NSW, Australia.,Ageing and Alzheimers Institute, Centre for Education and Research on Ageing and Anzac Research Institute, Concord Hospital and University of Sydney, Sydney, NSW, Australia
| | - David G Le Couteur
- Sydney Medical School, Univ of Sydney, Sydney, NSW, Australia.,Ageing and Alzheimers Institute, Centre for Education and Research on Ageing and Anzac Research Institute, Concord Hospital and University of Sydney, Sydney, NSW, Australia
| | - Sarah N Hilmer
- Laboratory of Ageing and Pharmacology, Kolling Institute of Medical Research, Sydney, NSW, Australia.,Department of Clin Pharmacol and Aged Care, Royal North Shore Hosp, Sydney, NSW, Australia.,Sydney Medical School, Univ of Sydney, Sydney, NSW, Australia
| |
Collapse
|
13
|
De Kesel PMM, Lambert WE, Stove CP. Alternative Sampling Strategies for Cytochrome P450 Phenotyping. Clin Pharmacokinet 2015; 55:169-84. [DOI: 10.1007/s40262-015-0306-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
14
|
Abstract
Esophageal cancer (EC) is one of the most common malignancies in low- and medium-income countries and represents a disease of public health importance because of its poor prognosis and high mortality rate in these regions. The striking variation in the prevalence of EC among different ethnic groups suggests a significant contribution of population-specific environmental and dietary factors to susceptibility to the disease. Although individuals within a demarcated geographical area are exposed to the same environment and share similar dietary habits, not all of them will develop the disease; thus genetic susceptibility to environmental risk factors may play a key role in the development of EC. A wide range of xenobiotic-metabolizing enzymes are responsible for the metabolism of carcinogens introduced via the diet or inhaled from the environment. Such dietary or environmental carcinogens can bind to DNA, resulting in mutations that may lead to carcinogenesis. Genes involved in the biosynthesis of these enzymes are all subject to genetic polymorphisms that can lead to altered expression or activity of the encoded proteins. Genetic polymorphisms may, therefore, act as molecular biomarkers that can provide important predictive information about carcinogenesis. The aim of this review is to discuss our current knowledge on the genetic risk factors associated with the development of EC in different populations; it addresses mainly the topics of genetic polymorphisms, gene-environment interactions, and carcinogenesis. We have reviewed the published data on genetic polymorphisms of enzymes involved in the metabolism of xenobiotics and discuss some of the potential gene-environment interactions underlying esophageal carcinogenesis. The main enzymes discussed in this review are the glutathione S-transferases (GSTs), N-acetyltransferases (NATs), cytochrome P450s (CYPs), sulfotransferases (SULTs), UDP-glucuronosyltransferases (UGTs), and epoxide hydrolases (EHs), all of which have key roles in the detoxification of environmental and dietary carcinogens. Finally, we discuss recent advances in the study of genetic polymorphisms associated with EC risk, specifically with regard to genome-wide association studies, and examine possible challenges of case-control studies that need to be addressed to better understand the interaction between genetic and environmental factors in esophageal carcinogenesis.
Collapse
Affiliation(s)
- Marco Matejcic
- a International Centre for Genetic Engineering and Biotechnology, Cape Town Component , Observatory , Cape Town , South Africa , and
| | | |
Collapse
|
15
|
Thierauf-Emberger A, Franz A, Auwärter V, Huppertz LM. Detection of the ethanol consumption markers ethyl glucuronide and ethyl sulfate in urine samples from inmates of two German prisons. Int J Legal Med 2015; 130:387-91. [PMID: 26160754 DOI: 10.1007/s00414-015-1222-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/22/2015] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Abstinence from ethanol is necessary in various situations. Among these are jail terms. Nevertheless, it is a matter of fact that ethanol is illegally produced and ingested in prisons. So far, data regarding drug prevalence in jail have mainly been collected by questionnaires. To get an objective database for the prevalence of ethanol consumption in jail, a cross-sectional study was performed. METHODS Inmates of two German prisons (Offenburg and Freiburg) were asked to give a urine sample at an unknown and random point of time. Participation was voluntary and did lead to neither negative consequences nor benefits. All samples were anonymized. Using the consumption markers ethyl glucuronide (EtG) and ethyl sulfate (EtS), the urine samples were tested for previous ethanol consumption. Analyses were performed by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. RESULTS In total 676 male inmates participated in this study. The participation rate was 70-75% of all permanent inmates in Offenburg and 30.6% in Freiburg. Ten of the 555 (1.8%) samples from Offenburg and 1 of the 121 (0.8%) samples from Freiburg were positive for ethanol consumption markers with concentrations ranging from trace amounts to 1400 ng/mL for EtG and up to 510 ng/mL for EtS, respectively. CONCLUSIONS The number of participants in this study was rather high, so that the results represent a good cross section, at least for Offenburg, the jail with the higher number of positive samples.
Collapse
Affiliation(s)
- Annette Thierauf-Emberger
- Medical Center - University of Freiburg, Institute of Forensic Medicine, Albertstraße 9, 79104, Freiburg, Germany.
| | - Anette Franz
- Medical Center - University of Freiburg, Institute of Forensic Medicine, Albertstraße 9, 79104, Freiburg, Germany
| | - Volker Auwärter
- Medical Center - University of Freiburg, Institute of Forensic Medicine, Albertstraße 9, 79104, Freiburg, Germany
| | - Laura M Huppertz
- Medical Center - University of Freiburg, Institute of Forensic Medicine, Albertstraße 9, 79104, Freiburg, Germany
| |
Collapse
|
16
|
Fohner AE, Robinson R, Yracheta J, Dillard DA, Schilling B, Khan B, Hopkins S, Boyer B, Black J, Wiener H, Tiwari HK, Gordon A, Nickerson D, Tsai JM, Farin FM, Thornton TA, Rettie AE, Thummel KE. Variation in genes controlling warfarin disposition and response in American Indian and Alaska Native people: CYP2C9, VKORC1, CYP4F2, CYP4F11, GGCX. Pharmacogenet Genomics 2015; 25:343-353. [PMID: 25946405 PMCID: PMC4461509 DOI: 10.1097/fpc.0000000000000143] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Pharmacogenetic testing is projected to improve health outcomes and reduce the cost of care by increasing therapeutic efficacy and minimizing drug toxicity. American Indian and Alaska Native (AI/AN) people historically have been excluded from pharmacogenetic research and its potential benefits, a deficiency we sought to address. The vitamin K antagonist warfarin is prescribed for prevention of thromboembolic events, although its narrow therapeutic index and wide interindividual variability necessitate close monitoring of drug response. Therefore, we were interested in variation in CYP2C9, VKORC1, CYP4F2, CYP4F11, and GGCX, which encode enzymes important for the activity of warfarin and synthesis of vitamin K-dependent blood clotting factors. METHODS We resequenced these genes in 188 AI/AN people in partnership with Southcentral Foundation in Anchorage, Alaska and 94 Yup'ik people living in the Yukon-Kuskokwim Delta of southwest Alaska to identify known or novel function-disrupting variation. We conducted genotyping for specific single nucleotide polymorphisms in larger cohorts of each study population (380 and 350, respectively). RESULTS We identified high frequencies of the lower-warfarin dose VKORC1 haplotype (-1639G>A and 1173C>T) and the higher-warfarin dose CYP4F2*3 variant. We also identified two relatively common, novel, and potentially function-disrupting variants in CYP2C9 (M1L and N218I), which, along with CYP2C9*3, CYP2C9*2, and CYP2C9*29, predict that a significant proportion of AI/AN people will have decreased CYP2C9 activity. CONCLUSION Overall, we predict a lower average warfarin dose requirement in AI/AN populations in Alaska than that seen in non-AI/AN populations of the USA, a finding consistent with clinical experience in Alaska.
Collapse
Affiliation(s)
- Alison E Fohner
- Department of Pharmaceutics, University of Washington, Seattle, WA
| | | | - Joseph Yracheta
- Department of Pharmaceutics, University of Washington, Seattle, WA
| | | | | | | | - Scarlett Hopkins
- Center for Alaska Native Health Research, University of Alaska Fairbanks, Fairbanks, AK
| | - Bert Boyer
- Center for Alaska Native Health Research, University of Alaska Fairbanks, Fairbanks, AK
| | - Jynene Black
- Center for Alaska Native Health Research, University of Alaska Fairbanks, Fairbanks, AK
| | - Howard Wiener
- School of Public Health, University of Alabama at Birmingham, Birmingham, AL
| | - Hemant K Tiwari
- School of Public Health, University of Alabama at Birmingham, Birmingham, AL
| | - Adam Gordon
- Department of Genome Sciences, University of Washington, Seattle WA
| | | | - Jesse M Tsai
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Federico M Farin
- Department of Environmental and Occupational Health Sciences, University of Washington
| | | | - Allan E Rettie
- Department of Medicinal Chemistry, University of Washington
| | | |
Collapse
|
17
|
Preissner S, Simmaco M, Gentile G, Preissner R. Personalized Cancer Therapy Considering Cytochrome P450 Variability. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2015; 74:113-30. [PMID: 26233905 DOI: 10.1016/bs.apha.2015.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The individual variability of pharmacokinetics is underestimated and few systematic studies exist in this field. In most cases, this leads to unwanted side effects or toxicity. In polychemotherapy, prodrugs (like ifosfamide), which have to be activated by cytochrome P450 enzymes (CYPs), play an important role. If patients are poor metabolizers for these drugs, the therapy will be ineffective. Furthermore, CYPs and transporters can be (over)expressed in target tissues, which is also not examined and considered in clinical routine. Here, we present a body map showing relevant enzymes in some organs and tissues. Finally, a typical case of a Caucasian chemotherapy patient with breast cancer is presented and discussed regarding a personalized cancer therapy considering the single nucleotide polymorphisms found via genotyping.
Collapse
Affiliation(s)
- Saskia Preissner
- Dental, Oral and Maxillary Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.
| | - Maurizio Simmaco
- NESMOS Department, Faculty of Medicine and Psychology, Sapienza University of Rome, Rome, Italy; Advanced Molecular Diagnostics Unit, Sant'Andrea Hospital, Rome, Italy
| | - Giovanna Gentile
- NESMOS Department, Faculty of Medicine and Psychology, Sapienza University of Rome, Rome, Italy; Advanced Molecular Diagnostics Unit, Sant'Andrea Hospital, Rome, Italy
| | - Robert Preissner
- Structural Bioinformatics Group, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
18
|
Pawlowska M, Bogiel M, Duda J, Sieradzki E. Influence of CYP2D6 and CYP2C19 genetic polymorphism on the pharmacokinetics of tolperisone in healthy volunteers. Eur J Clin Pharmacol 2015; 71:699-705. [PMID: 25953735 DOI: 10.1007/s00228-015-1856-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 04/29/2015] [Indexed: 11/28/2022]
Abstract
PURPOSE This is the first study that connects pharmacokinetics of tolperisone with genetic polymorphism of the enzymes involved in its metabolism in human. We aimed to identify the influence of polymorphism of two main enzymes (CYP2D6 and CYP2C19) on pharmacokinetic profile of parent drug. METHODS In a single-dose study, 28 healthy Caucasian male volunteers received an oral dose of 150 mg of tolperisone. The subjects were genotyped with respect to CYP2D6 and CYP2C19 enzymes. Plasma was sampled for up to 12 h post dose, followed by quantification of tolperisone by a fully validated HPLC-tandem mass spectrometry (MS/MS) method. The pharmacokinetic parameters were estimated using a non-compartmental method and compared statistically at level p < 0.05 across the genotyped groups. RESULTS High variability (exceeded 100%) of main bioavailability parameters (AUCt, AUC(inf), C(max)) was observed in the whole group of subjects. An essential difference in the pharmacokinetics of tolperisone of quick metabolizers whose genotype expressed wild homozygote CYP2D6 *1/*1 with respect to heterozygous *1/*4 and *1/*5 subjects was demonstrated. The mean AUC(inf) was 2.1- and 3.4-fold higher in *1/*4 and *1/*5, respectively, than in *1/*1 subjects. In case of Cmax, the differences were greater and reached maximally 3.8 times (mean values 54.00, 98.85, and 205.20 ng/mL for CYP2D6 *1/*1, *1/*4, and *1/*5, respectively). Values of the parameters for the one subject that expressed *4/*4 genotype were even 8.5 times higher than in subjects with extensive or intermediate phenotype. Although CYP2C19 *1/*2 subjects had higher AUCt, AUC(inf), and Cmax values than *1/*1, no statistically significant differences were observed. Oral clearance (CL/F) significantly decreased by 65.7% in heterozygous *1/*2 relative to homozygous *1/*1 extensive metabolizers. CONCLUSION In this study, we first demonstrated the effect of CYP2D6 polymorphism on pharmacokinetics of tolperisone in Caucasian subjects. The contribution of CYP2C19 enzyme seems to be less important.
Collapse
Affiliation(s)
- M Pawlowska
- Institute of Biotechnology and Antibiotics, Warsaw, Poland.
| | - M Bogiel
- Institute of Biotechnology and Antibiotics, Warsaw, Poland
| | - J Duda
- Institute of Biotechnology and Antibiotics, Warsaw, Poland
| | - E Sieradzki
- Faculty of Pharmacy, Department of Applied Pharmacy and Bioengineering, Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|
19
|
Darwish MH, Farah RA, Farhat GN, Torbey PHN, Ghandour FA, Bejjani-Doueihy NA, Dhaini HR. Association of CYP3A4/5 genotypes and expression with the survival of patients with neuroblastoma. Mol Med Rep 2014; 11:1462-8. [PMID: 25370902 DOI: 10.3892/mmr.2014.2835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 07/30/2014] [Indexed: 11/06/2022] Open
Abstract
Neuroblastoma (NB) is a rare pediatric disease in Lebanon for which poor prognosis remains a major challenge. Genetic polymorphism of genes coding for drug‑metabolizing enzymes may influence the response of a patient to chemotherapy. This study investigates a possible association between CYP3A4/5 polymorphism and expression levels and survival in NB patients. All patients with stage III and IV NB diagnosed between 1993 and 2012 in three major hospitals in Beirut were included (n=27). Demographic information and survival time were obtained from medical records. CYP3A4 and CYP3A5 genotypes and expression levels were determined in archival tumors by polymerase chain reaction (PCR) and restriction fragment length polymorphism and quantitative PCR, respectively. Additionally, MYCN amplification was assessed. A Cox proportional hazards model was used to evaluate potential associations, adjusting for MYCN amplification. A statistically significant increase in the risk of mortality was observed in patients with MYCN amplification [hazard ratio (HR) 4.11, 95% confidence interval (CI) 1.14‑14.80]. Patients with CYP3A5 expression levels above the median had a lower risk of mortality (HR 0.61, 95% CI 0.21‑1.74) and patients with CYP3A4 expression levels above the median had a higher risk of mortality (HR 2.00, 95% CI 0.67‑5.90). CYP3A5*3/*3 homozygote mutants had a 4.3‑fold increase in the risk of mortality compared with that of homozygote wild‑type or heterozygote mutants (HR 4.30, 95% CI 0.56‑33.30). Carriers of the CYP3A4*1B mutant allele had a 52% lower risk of mortality compared with that of non‑carriers (HR 0.48, 95% CI 0.06‑3.76). Although the results of the present study did not achieve statistical significance, associations were observed, which indicates that CYP3A4 and CYP3A5 may modulate the clinical outcome of NB. Further studies with larger sample sizes are required to characterize the effects of the polymorphism and expression levels of CYP3A4/5 on the survival of patients with NB.
Collapse
Affiliation(s)
- Mohamad H Darwish
- Department of Medical Lab Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100‑2807, Lebanon
| | - Roula A Farah
- Department of Pediatric Oncology, Saint George Hospital University Medical Center, Beirut 1100‑2807, Lebanon
| | - Ghada N Farhat
- Department of Medical Lab Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100‑2807, Lebanon
| | - Paul-Henri N Torbey
- Department of Pediatrics, Hotel Dieu De France Hospital, Beirut 1100‑2190, Lebanon
| | - Fatima A Ghandour
- Department of Pathology, Saint George Hospital University Medical Center, Beirut 1100‑2807, Lebanon
| | - Noha A Bejjani-Doueihy
- Department of Pathology, University Medical Center ‑ Rizk Hospital, Beirut 11-3288, Lebanon
| | - Hassan R Dhaini
- Department of Medical Lab Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100‑2807, Lebanon
| |
Collapse
|
20
|
In vivo radioactive metabolite analysis for individualized medicine: a basic study of a new method of CYP activity assay using (123)I-IMP. Nucl Med Biol 2014; 42:171-6. [PMID: 25441254 DOI: 10.1016/j.nucmedbio.2014.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/25/2014] [Accepted: 08/25/2014] [Indexed: 11/24/2022]
Abstract
INTRODUCTION (123)I-N-isopropyl-p-iodoamphetamine ((123)I-IMP) is metabolized and converted to (123)I-p-iodoamphetamine ((123)I-PIA) by CYP2C19 in humans. Since variations in (123)I-PIA levels reflect variations in CYP2C19 activity, CYP2C19 activity can be estimated by quantitative analysis of (123)I-PIA levels. Thus, (123)I-IMP administration can provide diagnostic information not only regarding cerebral blood flow (rCBF) but also regarding metabolic function. The aim of the present study was to detect variations in CYP activity in mice using metabolite analysis. METHODS Metabolism of (125)I-IMP in pooled homogenates of mouse liver (MLH) was analyzed by high-performance liquid chromatography (HPLC) in the presence or absence of NADPH. The amount of (125)I-PIA generated was calculated as the normalized peak area of the chromatogram. Inhibition of (125)I-IMP metabolism was evaluated using the inhibitor SKF-525A. A biodistribution study of (125)I-IMP was performed to determine the organ distribution of (125)I-IMP/(125)I-IMP metabolites and the effect of SKF-525A. Variations in CYP activity in vivo were detected by administration of (123)I-IMP and/or SKF-525A to mice. The liver and the kidney were then excised, homogenized and analyzed using HPLC. RESULTS (125)I-IMP was metabolized by MLH in the presence of NADPH, and the production of (125)I-PIA was inhibited by SKF-525A. SKF-525A did not greatly affect the biodistribution of (125)I-IMP/(125)I-IMP metabolites in vivo. Both (123)I-IMP and (123)I-PIA were detected in organs of control mice. However, (123)I-PIA was not detected in the livers or kidneys of mice treated with SKF-525A. CONCLUSIONS CYP activity in vivo was inhibited by SKF-525A treatment. Variations in CYP activity could be detected in the blood, liver and kidney as changes in the peak area of (123)I-PIA. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE (123)I-IMP metabolite analysis has the potential to provide beneficial information for prediction of the effect of medicines, in addition to its contribution to more accurate rCBF diagnosis that reflects individual CYP activity.
Collapse
|
21
|
Jenkins MM, Reefhuis J, Gallagher ML, Mulle JG, Hoffmann TJ, Koontz DA, Sturchio C, Rasmussen SA, Witte JS, Richter P, Honein MA. Maternal smoking, xenobiotic metabolizing enzyme gene variants, and gastroschisis risk. Am J Med Genet A 2014; 164A:1454-63. [PMID: 24668907 DOI: 10.1002/ajmg.a.36478] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 01/09/2014] [Indexed: 01/11/2023]
Abstract
Maternal smoking during pregnancy is one proposed risk factor for gastroschisis, but reported associations have been modest, suggesting that differences in genetic susceptibility might play a role. We included 108 non-Hispanic white and 62 Hispanic families who had infants with gastroschisis, and 1,147 non-Hispanic white and 337 Hispanic families who had liveborn infants with no major structural birth defects (controls) in these analyses. DNA was extracted from buccal cells collected from infants and mothers, and information on periconceptional smoking history was obtained from maternal interviews, as part of the National Birth Defects Prevention Study. We analyzed five polymorphisms in three genes that code for enzymes involved in metabolism of some cigarette smoke constituents (CYP1A1, CYP1A2, and NAT2). Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) independently for maternal smoking and maternal and infant gene variants, and to assess joint associations of maternal smoking and maternal or infant gene variants with gastroschisis. In analyses adjusted for maternal age at delivery and stratified by maternal race-ethnicity, we identified three suggestive associations among 30 potential associations with sufficient numbers to calculate ORs: CYP1A1*2A for non-Hispanic white mothers who smoked periconceptionally (aOR = 0.38, 95% CI 0.15-0.98), and NAT2*6 for Hispanic non-smoking mothers (aOR = 2.17, 95% CI 1.12-4.19) and their infants (aOR = 2.11, 95% CI 1.00-4.48). This analysis does not support the occurrence of effect modification between periconceptional maternal smoking and most of the xenobiotic metabolizing enzyme gene variants assessed.
Collapse
Affiliation(s)
- Mary M Jenkins
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Coffee consumption and prostate cancer risk: an updated meta-analysis. Cancer Causes Control 2014; 25:591-604. [PMID: 24584929 DOI: 10.1007/s10552-014-0364-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 02/19/2014] [Indexed: 12/18/2022]
Abstract
PURPOSE Many epidemiological studies have been conducted to explore the association between coffee consumption and prostate cancer. However, the results remain inconsistent. We performed a large meta-analysis of relevant studies to derive a more precise estimation of this relationship. METHODS Systematic searches of PubMed and several other databases up to June 2013 were retrieved. All epidemiologic studies regarding coffee consumption and prostate cancer risk were included, and odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated to estimate the strength of the association. RESULTS Twelve case-control studies involving 7,909 prostate cancer cases and 9,461 controls and nine cohort studies involving 455,123 subjects were included in our analysis. Compared with the lowest category, the unstratified highest category of coffee consumption showed a significance reduction in prostate cancer risk of a fixed-effects model (OR 0.91, CI 0.86-0.97). A borderline significant influence was also found when the stratified highest category (US ≥ 4, Europe ≥ 5) of coffee consumption was compared with the reference category (OR 0.96, CI 0.92-1.00), but no relationships were observed for the other two categories. In another analysis conducted by coffee consumption and prostate cancer stage and Gleason grade, our results showed a significant inverse association in all categories of prostate cancer except Gleason <7 grade in a fixed-effects model; the results remained the same, except for advanced prostate cancer, in a random-effects model. CONCLUSIONS Our meta-analysis suggests that high (e.g., highest ≥ 4 or 5 cups/day) coffee consumption may not only be associated with a reduced risk of overall prostate cancer, but also inversely associated with fatal and high-grade prostate cancer.
Collapse
|
23
|
Application of enzyme bioluminescence for medical diagnostics. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2014; 144:175-97. [PMID: 25084998 DOI: 10.1007/978-3-662-43385-0_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nowadays luciferases are effectively used as analytical instruments in a great variety of research fields. Of special interest are the studies dealing with elaboration of novel analytical systems for the purposes of medical diagnostics. The ever-expanding spectrum of clinically important analytes accounts for the increasing demand for new techniques for their detection. In this chapter we have made an attempt to summarize the results on applications of luciferases as reporters in binding assays including immunoassay, nucleic acid hybridization assay, and so on. The data over the last 15 years have been analyzed and clearly show that luciferase-based assays, due to extremely high sensitivity, low cost, and the lack of need for skilled personnel, hold much promise for clinical diagnostics.
Collapse
|
24
|
Abstract
The efficacy, safety, and tolerability of drugs are dependent on numerous factors that influence their disposition. A dose that is efficacious and safe for one individual may result in sub-therapeutic or toxic blood concentrations in other individuals. A major source of this variability in drug response is drug metabolism, where differences in pre-systemic and systemic biotransformation efficiency result in variable degrees of systemic exposure (e.g., AUC, C max, and/or C min) following administration of a fixed dose.Interindividual differences in drug biotransformation have been studied extensively. It is well recognized that both intrinsic (such as genetics, age, sex, and disease states) and extrinsic (such as diet, chemical exposures from the environment, and even sunlight) factors play a significant role. For the family of cytochrome P450 enzymes, the most critical of the drug metabolizing enzymes, genetic variation can result in the complete absence or enhanced expression of a functional enzyme. In addition, up- and down-regulation of gene expression, in response to an altered cellular environment, can achieve the same range of metabolic function (phenotype), but often in a less reliably predictable and time-dependent manner. Understanding the mechanistic basis for drug disposition and response variability is essential if we are to move beyond the era of empirical, trial-and-error dose selection and into an age of personalized medicine that brings with it true improvements in health outcomes in the therapeutic treatment of disease.
Collapse
Affiliation(s)
- Kenneth E Thummel
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | | |
Collapse
|
25
|
Abstract
Pharmacogenetics takes into account the individual variability of the genome and its relationships with drug activity. Numerous gene polymorphisms occurring at the level of drug metabolising enzymes, drug transporters or drug targets have been identified; they may be responsible for an alteration of the phenotype, and of individual changes in drug efficacy and/or toxicity. Pharmacogenomics takes into account the genetic alterations present in tumours and their role in drug activity. It may be possible to establish correlations between the activity of a drug and the level of expression of tumour genes, and thus select the most appropriate drugs to prescribe for the treatment of individual tumours. Pharmacogenetics and pharmacogenomics are acting synergistically for the personalisation of treatments, on the basis of the constitutive singularity of patients and of the molecular characteristics of tumours.
Collapse
Affiliation(s)
- J Robert
- Université Victor Segalen Bordeaux 2, Institut Bergonié, 33076 Bordeaux Cedex, France.
| |
Collapse
|
26
|
Role of xenobiotic metabolism enzyme gene polymorphism in the formation of chemotherapy resistance in patients with chronic lymphoproliferative diseases. Bull Exp Biol Med 2013; 155:676-9. [PMID: 24288737 DOI: 10.1007/s10517-013-2223-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Enzymes of the cytochrome P450 and GSTP1 families play a pivotal role in the metabolism of a wide variety of antitumor drugs and polymorphisms of genes encoding for metabolizing enzymes can affect drug efficacy and toxicity. We studied the associations between functionally significant gene polymorphisms CYP2C8, CYP2C9, CYP2C19, CYP3A5, and GSTP1 and clinical response to chemotherapy in patients with chronic lymphoproliferative diseases. Significant correlations with chemotherapy resistance were observed for CYP2C8 3 (OR=7.05; CI 95%=1.76-29.55) and CYP2C9 2 polymorphisms (OR=4.1; CI 95%=1.03-16.81). No significant association between chemotherapy resistance and other examined polymorphisms were found.
Collapse
|
27
|
Tabari RG, Marjani A, Ataby OA, Mansourian AR, Samai NM. Genetic Polymorphism of Cytochrome p450 (2C19) Enzyme in Iranian Turkman Ethnic Group. Oman Med J 2013; 28:237-44. [PMID: 23904915 DOI: 10.5001/omj.2013.69] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/28/2013] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Different findings indicate that CYP2C plays a clinical role in determining interindividual and interethnic differences in drug effectiveness. The ethnic differences in the frequency of CYP2C19 mutant alleles continue to be a significant study topic. The aim of the present study was to assess the frequency of allelic variants of CYP2C19 in Turkman ethnic groups and compare them with the frequencies in other ethnic populations. METHODS The study group included 140 unrelated healthy ethnic Turkman subject referred to the Health Center. Genotyping of CYP2C19 alleles (CYP2C19*1, CYP2C19*2, and CYP2C19*3 alleles) was carried out by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism technique. RESULTS The allele frequency of CYP2C19*1, CYP2C19*2 and CYP2C19*3 were 56.43%, 23.57% and 20%, respectively. The result also showed that 39.7% of subjects expressed the CYP2C19*1/*1 genotype. While 42.1%, 9.3%, 9.3% and 1.4% expressed CYP2C19*1/*2, CYP2C19*1/*3, CYP2C19*2/*2 and CYP2C19*3/*3 genotypes, respectively. The genotype CYP2C19*2/*3 was not expressed in this study population. The findings suggested that 10% of subjects were poor metabolizers by expressing CYP2C19*2/*2 and CYP2C19*3/*3 genotypes. Fifty one percent of subjects were intermediate metabolizers having CYP2C19*1/*2, CYP2C19*2/*3 and CYP2C19*1/*3 genotypes and 37.86% were found to be extensive metabolizers expressing CYP2C19*1/*1 genotype. The frequency of intermediate metabolizers genotype was high (51%) in Turkman ethnic groups. CONCLUSION This study showed that the determined allelic variants of CYP2C19 (CYP2C19*2 and CYP2C19*3 mutations) in Turkman ethnic group are comparable to other populations. These findings could be useful for the clinicians in different country to determine optimal dosage and effectiveness of drugs metabolized by this polymorphic enzyme.
Collapse
Affiliation(s)
- Robabeh Ghiyas Tabari
- Department of Biochemistry and Biophysics, Metabolic Disorders Research Center, Gorgan Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Golestan province, Iran
| | | | | | | | | |
Collapse
|
28
|
Samer CF, Lorenzini KI, Rollason V, Daali Y, Desmeules JA. Applications of CYP450 testing in the clinical setting. Mol Diagn Ther 2013; 17:165-84. [PMID: 23588782 PMCID: PMC3663206 DOI: 10.1007/s40291-013-0028-5] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Interindividual variability in drug response is a major clinical problem. Polymedication and genetic polymorphisms modulating drug-metabolising enzyme activities (cytochromes P450, CYP) are identified sources of variability in drug responses. We present here the relevant data on the clinical impact of the major CYP polymorphisms (CYP2D6, CYP2C19 and CYP2C9) on drug therapy where genotyping and phenotyping may be considered, and the guidelines developed when available. CYP2D6 is responsible for the oxidative metabolism of up to 25% of commonly prescribed drugs such as antidepressants, antipsychotics, opioids, antiarrythmics and tamoxifen. The ultrarapid metaboliser (UM) phenotype is recognised as a cause of therapeutic inefficacy of antidepressant, whereas an increased risk of toxicity has been reported in poor metabolisers (PMs) with several psychotropics (desipramine, venlafaxine, amitriptyline, haloperidol). CYP2D6 polymorphism influences the analgesic response to prodrug opioids (codeine, tramadol and oxycodone). In PMs for CYP2D6, reduced analgesic effects have been observed, whereas in UMs cases of life-threatening toxicity have been reported with tramadol and codeine. CYP2D6 PM phenotype has been associated with an increased risk of toxicity of metoprolol, timolol, carvedilol and propafenone. Although conflicting results have been reported regarding the association between CYP2D6 genotype and tamoxifen effects, CYP2D6 genotyping may be useful in selecting adjuvant hormonal therapy in postmenopausal women. CYP2C19 is responsible for metabolising clopidogrel, proton pump inhibitors (PPIs) and some antidepressants. Carriers of CYP2C19 variant alleles exhibit a reduced capacity to produce the active metabolite of clopidogrel, and are at increased risk of adverse cardiovascular events. For PPIs, it has been shown that the mean intragastric pH values and the Helicobacter pylori eradication rates were higher in carriers of CYP2C19 variant alleles. CYP2C19 is involved in the metabolism of several antidepressants. As a result of an increased risk of adverse effects in CYP2C19 PMs, dose reductions are recommended for some agents (imipramine, sertraline). CYP2C9 is responsible for metabolising vitamin K antagonists (VKAs), non-steroidal anti-inflammatory drugs (NSAIDs), sulfonylureas, angiotensin II receptor antagonists and phenytoin. For VKAs, CYP2C9 polymorphism has been associated with lower doses, longer time to reach treatment stability and higher frequencies of supratherapeutic international normalised ratios (INRs). Prescribing algorithms are available in order to adapt dosing to genotype. Although the existing data are controversial, some studies have suggested an increased risk of NSAID-associated gastrointestinal bleeding in carriers of CYP2C9 variant alleles. A relationship between CYP2C9 polymorphisms and the pharmacokinetics of sulfonylureas and angiotensin II receptor antagonists has also been observed. The clinical impact in terms of hypoglycaemia and blood pressure was, however, modest. Finally, homozygous and heterozygous carriers of CYP2C9 variant alleles require lower doses of phenytoin to reach therapeutic plasma concentrations, and are at increased risk of toxicity. New diagnostic techniques made safer and easier should allow quicker diagnosis of metabolic variations. Genotyping and phenotyping may therefore be considered where dosing guidelines according to CYP genotype have been published, and help identify the right molecule for the right patient.
Collapse
Affiliation(s)
- C F Samer
- Clinical Pharmacology and Toxicology, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1211, Geneva, Switzerland.
| | | | | | | | | |
Collapse
|
29
|
Chamnanphon M, Pechatanan K, Sirachainan E, Trachu N, Chantratita W, Pasomsub E, Noonpakdee W, Sensorn I, Sukasem C. Association of CYP2D6 and CYP2C19 polymorphisms and disease-free survival of Thai post-menopausal breast cancer patients who received adjuvant tamoxifen. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2013; 6:37-48. [PMID: 23776391 PMCID: PMC3681433 DOI: 10.2147/pgpm.s42330] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To investigate the impact of CYP2D6 and CYP2C19 polymorphisms in predicting tamoxifen efficacy and clinical outcomes in Thai breast cancer patients. METHODS Polymorphisms of CYP2D6 and CYP2C19 were genotyped by the AmpliChip™ CYP450 Test (Roche Molecular Diagnostics, Branchburg, NJ, USA) for 57 patients, who were matched as recurrent versus non-recurrent breast cancers (n = 33 versus n = 24, respectively, with a 5-year follow-up). RESULTS Based on the genotype data, five CYP2D6 predicted phenotype groups were identified in this study including homozygous extensive metabolizer (13 of 57, 22.80%), extensive/intermediate metabolizer (23 of 57, 40.40%), extensive/poor metabolizer (3 of 57, 5.30%), homozygous intermediate metabolizer (14 of 57, 24.50%), and intermediate/poor metabolizer (4 of 57, 7.00%), and three CYP2C19 genotype groups including homozygous extensive metabolizer (27 of 57, 47.40%), extensive/intermediate metabolizer (27 of 57, 47.40%), and homozygous poor metabolizer (3 of 57, 5.30%). The CYP2D6 variant alleles were *10 (52 of 114, 45.60%), *5 (5 of 114, 4.40%), *41 (2 of 114, 1.80%), *4 (1 of 114, 0.90%), and *36 (1 of 114, 0.90%); the CYP2C19 variant alleles were *2 (27 of 114, 23.70%) and *3 (6 of 114, 5.30%). Kaplan-Meier estimates showed significantly shorter disease-free survival in patients with homozygous TT when compared to those with heterozygous CT or homozygous CC at nucleotides 100C>T and 1039C>T (CYP2D6*10) post-menopausal (log-rank test; P = 0.046). They also had increased risk of recurrence, but no statistically significant association was observed (hazard ratio 3.48; 95% confidence interval 0.86-14.07; P = 0.080). CONCLUSION The CYP2D6 and CYP2C19 polymorphisms were not involved in tamoxifen efficacy. However, in the subgroup of post-menopausal women, the polymorphisms in CYP2D6 and CYP2C19 might be useful in predicting tamoxifen efficacy and clinical outcomes in breast cancer patients receiving adjuvant tamoxifen treatment. As the number of breast cancer patients was relatively small in this study, results should be confirmed in a larger group of prospective patients.
Collapse
Affiliation(s)
- Montri Chamnanphon
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Kirsch F, Buettner A. Characterisation of the metabolites of 1,8-cineole transferred into human milk: concentrations and ratio of enantiomers. Metabolites 2013; 3:47-71. [PMID: 24957890 PMCID: PMC3901259 DOI: 10.3390/metabo3010047] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 01/16/2013] [Accepted: 01/21/2013] [Indexed: 12/15/2022] Open
Abstract
1,8-Cineole is a widely distributed odorant that also shows physiological effects, but whose human metabolism has hitherto not been extensively investigated. The aim of the present study was, thus, to characterise the metabolites of 1,8-cineole, identified previously in human milk, after the oral intake of 100 mg of this substance. Special emphasis was placed on the enantiomeric composition of the metabolites since these data may provide important insights into potential biotransformation pathways, as well as potential biological activities of these substances, for example on the breastfed child. The volatile fraction of the human milk samples was therefore isolated via Solvent Assisted Flavour Evaporation (SAFE) and subjected to gas chromatography-mass spectrometry (GC-MS). The absolute concentrations of each metabolite were determined by matrix calibration with an internal standard, and the ratios of enantiomers were analysed on chiral capillaries. The concentrations varied over a broad range, from traces in the upper ng/kg region up to 40 µg/kg milk, with the exception of the main metabolite α2-hydroxy-1,8-cineole that showed concentrations of 100-250 µg/kg. Also, large inter- and intra-individual variations were recorded for the enantiomers, with nearly enantiomerically pure α2-hydroxy- and 3-oxo-1,8-cineole, while all other metabolites showed ratios of ~30:70 to 80:20.
Collapse
Affiliation(s)
- Frauke Kirsch
- Department of Chemistry and Pharmacy, Food Chemistry, Emil Fischer Center, University of Erlangen-Nuremberg, 91052 Erlangen, Germany.
| | - Andrea Buettner
- Department of Chemistry and Pharmacy, Food Chemistry, Emil Fischer Center, University of Erlangen-Nuremberg, 91052 Erlangen, Germany.
| |
Collapse
|
31
|
Saeed LH, Mayet AY. Genotype-phenotype analysis of CYP2C19 in healthy saudi individuals and its potential clinical implication in drug therapy. Int J Med Sci 2013; 10:1497-502. [PMID: 24046523 PMCID: PMC3775106 DOI: 10.7150/ijms.6795] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/29/2013] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED CYP2C19 is a cytochrome P450 enzyme, which is involved in the metabolism of some clinically important medications and is encoded by a highly polymorphic gene. There is no available data on the distribution of the CYP2C19 *4 and *17 mutant alleles in the Saudi Arabian population. The aim of the study was to determine different CYP2C19 mutant allele (*2, *4 and *17) frequencies in healthy Saudi subjects and to determine genotype frequencies for these mutations. The CYP2C19 genotypes were then classified into phenotypes. RESULT In 201 adults of Saudi ethnicity, the allele frequencies were CYP2C19*1 (62.9%), *17 (25.7%), *2 (11.2%) and *4 (0.2%). The most prevalent genotype combinations were CYP2C19 *1/*1 (40.3%) and *1/*17 (30.4%). The distribution of CYP2C19 phenotypes was divided into extensive metabolizers (EM) 77.6%, intermediate metabolizers (IM) 14.9%, ultra-rapid metabolizers (UM) 7% and poor metabolizers (PM) 0.4%. This finding has important clinical implications for the use of CYP2C19 metabolized medications in the Saudi population and further studies are needed.
Collapse
Affiliation(s)
- Leena H Saeed
- 1. King Fahad Medical City, P.O. Box 59046, Riyadh 11525, Kingdom of Saudi Arabia
| | | |
Collapse
|
32
|
Maenhout TM, De Buyzere ML, Delanghe JR. Non-oxidative ethanol metabolites as a measure of alcohol intake. Clin Chim Acta 2012. [PMID: 23178443 DOI: 10.1016/j.cca.2012.11.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent alcohol intake can be monitored by the measurement of indirect biomarkers. Elevated levels of liver enzymes (i.e. gamma-glutamyl transferase (GGT), alanine amino transferase (ALT) and aspartate amino transferase (AST)) in blood are commonly used in clinical practice as an indicator of alcohol-induced liver damage. With the exception of carbohydrate-deficient transferrin (CDT), the specificity of indirect markers is only moderate because many cases of elevated levels are unrelated to alcohol consumption. Because of their intermediate half-life and tendency to accumulate in hair, non-oxidative ethanol metabolites can be used as markers with an intermediate timeframe between ethanol measurements and GGT and CDT with regard to recent alcohol consumption occurring between hours to 1 week. Additionally, these biomarkers offer a high ethanol-specificity in combination with approximately a two-fold higher sensitivity in comparison with indirect alcohol markers. In case of forensic use of direct ethanol metabolites, caution has to be taken in interpretation and pre-analytical pitfalls should be considered.
Collapse
Affiliation(s)
- Thomas M Maenhout
- Department of Clinical Chemistry, Ghent University Hospital, De Pintelaan 185, B 9000 Gent, Belgium
| | | | | |
Collapse
|
33
|
Rietjens SJ, Hondebrink L, Westerink RHS, Meulenbelt J. Pharmacokinetics and pharmacodynamics of 3,4-methylenedioxymethamphetamine (MDMA): interindividual differences due to polymorphisms and drug-drug interactions. Crit Rev Toxicol 2012; 42:854-76. [PMID: 23030234 DOI: 10.3109/10408444.2012.725029] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Clinical outcome following 3,4-methylenedioxymethamphetamine (MDMA) intake ranges from mild entactogenic effects to a life-threatening intoxication. Despite ongoing research, the clinically most relevant mechanisms causing acute MDMA-induced adverse effects remain largely unclear. This complicates the triage and treatment of MDMA users needing medical care. The user's genetic profile and interactions resulting from polydrug use are key factors that modulate the individual response to MDMA and influence MDMA pharmacokinetics and dynamics, and thus clinical outcome. Polymorphisms in CYP2D6, resulting in poor metabolism status, as well as co-exposure of MDMA with specific substances (e.g. selective serotonin reuptake inhibitors (SSRIs)) can increase MDMA plasma levels, but can also decrease the formation of toxic metabolites and subsequent cellular damage. While pre-exposure to e.g. SSRIs can increase MDMA plasma levels, clinical effects (e.g. blood pressure, heart rate, body temperature) can be reduced, possibly due to a pharmacodynamic interaction at the serotonin reuptake transporter (SERT). Pretreatment with inhibitors of the dopamine or norepinephrine reuptake transporter (DAT or NET), 5-HT(2A) or α-β adrenergic receptor antagonists or antipsychotics prior to MDMA exposure can also decrease one or more MDMA-induced physiological and/or subjective effects. Carvedilol, ketanserin and haloperidol can reduce multiple MDMA-induced clinical and neurotoxic effects. Thus besides supportive care, i.e. sedation using benzodiazepines, intravenous hydration, aggressive cooling and correction of electrolytes, it is worthwhile to investigate the usefulness of carvedilol, ketanserin and haloperidol in the treatment of MDMA-intoxicated patients.
Collapse
Affiliation(s)
- Saskia J Rietjens
- University Medical Center Utrecht, Division of Anesthesiology, Intensive Care and Emergency Medicine, National Poisons Information Center (NVIC), P.O. box 85500, 3508 GA, Utrecht, The Netherlands.
| | | | | | | |
Collapse
|
34
|
Bosch TM, Doodeman VD, Smits PHM, Meijerman I, Schellens JHM, Beijnen JH. Pharmacogenetic Screening for Polymorphisms in Drug-Metabolizing Enzymes and Drug Transporters in a Dutch Population. Mol Diagn Ther 2012; 10:175-85. [PMID: 16771603 DOI: 10.1007/bf03256456] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND A possible explanation for the wide interindividual variability in toxicity and efficacy of drug therapy is variation in genes encoding drug-metabolizing enzymes and drug transporters. The allelic frequency of these genetic variants, linkage disequilibrium (LD), and haplotype of these polymorphisms are important parameters in determining the genetic differences between patients. The aim of this study was to explore the frequencies of polymorphisms in drug-metabolizing enzymes (CYP1A1, CYP2C9, CYP2C19, CYP3A4, CYP2D6, CYP3A5, DPYD, UGT1A1, GSTM1, GSTP1, GSTT1) and drug transporters (ABCB1[MDR1] and ABCC2[MRP2]), and to investigate the LD and perform haplotype analysis of these polymorphisms in a Dutch population. METHODS Blood samples were obtained from 100 healthy volunteers and genomic DNA was isolated and amplified by PCR. The amplification products were sequenced and analyzed for the presence of polymorphisms by sequence alignment. RESULTS In the study population, we identified 13 new single nucleotide polymorphisms (SNPs) in Caucasians and three new SNPs in non-Caucasians, in addition to previously recognized SNPs. Three of the new SNPs were found within exons, of which two resulted in amino acid changes (A428T in CYP2C9 resulting in the amino acid substitution D143V; and C4461T in ABCC2 in a non-Caucasian producing the amino acid change T1476M). Several LDs and haplotypes were found in the Caucasian individuals. CONCLUSION In this Dutch population, the frequencies of 16 new SNPs and those of previously recognized SNPs were determined in genes coding for drug-metabolizing enzymes and drug transporters. Several LDs and haplotypes were also inferred. These data are important for further research to help explain the interindividual pharmacokinetic and pharmacodynamic variability in response to drug therapy.
Collapse
Affiliation(s)
- T M Bosch
- Department of Pharmacy & Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
35
|
Association of cytochrome P450 genetic polymorphisms with neoadjuvant chemotherapy efficacy in breast cancer patients. BMC MEDICAL GENETICS 2012; 13:45. [PMID: 22702493 PMCID: PMC3458973 DOI: 10.1186/1471-2350-13-45] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 05/22/2012] [Indexed: 01/29/2023]
Abstract
Background The enzymes of the cytochrome P450 family (CYPs) play an important role in the metabolism of a great variety of anticancer agents; therefore, polymorphisms in genes encoding for metabolizing enzymes and drugs transporters can affect drug efficacy and toxicity. Methods The genetic polymorphisms of cytochrome P450 were studied in 395 patients with breast cancer by RLFP analysis. Results Here, we studied the association of functionally significant variant alleles of CYP3A4, CYP3A5, CYP2B6, CYP2C8, CYP2C9 and CYP2C19 with the clinical response to neoadjuvant chemotherapy in breast cancer patients. A significant correlation was observed between the CYP2C9*2 polymorphism and chemotherapy resistance (OR = 4.64; CI 95% = 1.01 – 20.91), as well as between CYP2C9*2 heterozygotes and chemotherapy resistance in women with nodal forms of breast cancer and a cancer hereditary load (OR = 15.50; CI 95% = 1.08 – 826.12) when the potential combined effects were examined. No significant association between chemotherapy resistance and the other examined genotypes and the potential combined clinical and tumour-related parameters were discovered. Conclusion In conclusion, CYP2C9*2 was associated with neoadjuvant chemotherapy resistance (OR = 4.64; CI 95% = 1.01 – 20.91) in the population of interest.
Collapse
|
36
|
Kim HN, Kim NY, Yu L, Tran HTT, Kim YK, Lee IK, Shin MH, Park KS, Choi JS, Kim HJ. Association ofGSTT1polymorphism with acute myeloid leukemia risk is dependent on smoking status. Leuk Lymphoma 2012; 53:681-7. [DOI: 10.3109/10428194.2011.625576] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
37
|
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
|
38
|
Interplay of pharmacogenetic variations in ABCB1 transporters and cytochrome P450 enzymes. Arch Pharm Res 2011; 34:1817-28. [DOI: 10.1007/s12272-011-1104-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 08/28/2011] [Accepted: 09/05/2011] [Indexed: 01/11/2023]
|
39
|
Wilderman PR, Gay SC, Jang HH, Zhang Q, Stout CD, Halpert JR. Investigation by site-directed mutagenesis of the role of cytochrome P450 2B4 non-active-site residues in protein-ligand interactions based on crystal structures of the ligand-bound enzyme. FEBS J 2011; 279:1607-20. [PMID: 22051155 DOI: 10.1111/j.1742-4658.2011.08411.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Residues located outside the active site of cytochromes P450 2B have exhibited importance in ligand binding, structural stability and drug metabolism. However, contributions of non-active-site residues to the plasticity of these enzymes are not known. Thus, a systematic investigation was undertaken of unique residue-residue interactions found in crystal structures of P450 2B4 in complex with 4-(4-chlorophenyl)imidazole (4-CPI), a closed conformation, or in complex with bifonazole, an expanded conformation. Nineteen mutants distributed over 11 sites were constructed, expressed in Escherichia coli and purified. Most mutants showed significantly decreased expression, especially in the case of interactions found in the 4-CPI structure. Six mutants (H172A, H172F, H172Q, L437A, E474D and E474Q) were chosen for detailed functional analysis. Among these, the K(s) of H172F for bifonazole was ∼ 20 times higher than for wild-type 2B4, and the K(s) of L437A for 4-CPI was ∼ 50 times higher than for wild-type, leading to significantly altered inhibitor selectivity. Enzyme function was tested with the substrates 7-ethoxy-4-(trifluoromethyl)coumarin, 7-methoxy-4-(trifluoromethyl)coumarin and 7-benzyloxyresorufin (7-BR). H172F was inactive with all three substrates, and L437A did not turn over 7-BR. Furthermore, H172A, H172Q, E474D and E474Q showed large changes in k(cat)/K(M) for each of the three substrates, in some cases up to 50-fold. Concurrent molecular dynamics simulations yielded distances between some of the residues in these putative interaction pairs that are not consistent with contact. The results indicate that small changes in the protein scaffold lead to large differences in solution behavior and enzyme function.
Collapse
Affiliation(s)
- P Ross Wilderman
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA.
| | | | | | | | | | | |
Collapse
|
40
|
Moroy G, Martiny VY, Vayer P, Villoutreix BO, Miteva MA. Toward in silico structure-based ADMET prediction in drug discovery. Drug Discov Today 2011; 17:44-55. [PMID: 22056716 DOI: 10.1016/j.drudis.2011.10.023] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 10/07/2011] [Accepted: 10/21/2011] [Indexed: 12/12/2022]
Abstract
Quantitative structure-activity relationship (QSAR) methods and related approaches have been used to investigate the molecular features that influence the absorption, distribution, metabolism, excretion and toxicity (ADMET) of drugs. As the three-dimensional structures of several major ADMET proteins become available, structure-based (docking-scoring) computations can be carried out to complement or to go beyond QSAR studies. Applying docking-scoring methods to ADMET proteins is a challenging process because they usually have a large and flexible binding cavity; however, promising results relating to metabolizing enzymes have been reported. After reviewing current trends in the field we applied structure-based methods in the context of receptor flexibility in a case study involving the phase II metabolizing sulfotransferases. Overall, the explored concepts and results suggested that structure-based ADMET profiling will probably join the mainstream during the coming years.
Collapse
Affiliation(s)
- Gautier Moroy
- Inserm UMR-S 973, Molécules Thérapeutiques In Silico, Université Paris Diderot, Sorbonne Paris Cité, 35 Rue Helene Brion, 75013 Paris, France
| | | | | | | | | |
Collapse
|
41
|
Lewis BC, Mackenzie PI, Miners JO. Application of homology modeling to generate CYP1A1 mutants with enhanced activation of the cancer chemotherapeutic prodrug dacarbazine. Mol Pharmacol 2011; 80:879-88. [PMID: 21816953 DOI: 10.1124/mol.111.072124] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The chemotherapeutic prodrug dacarbazine (DTIC) has limited efficacy in human malignancies and exhibits numerous adverse effects that arise from systemic exposure to the cytotoxic metabolite. DTIC is activated by CYP1A1 and CYP1A2 catalyzed N-demethylation. However, structural features of these enzymes that confer DTIC N-demethylation have not been characterized. A validated homology model of CYP1A1 was employed to elucidate structure-activity relationships and to engineer CYP1A1 enzymes with altered DTIC activation. In silico docking demonstrated that DTIC orientates proximally to Ser122, Phe123, Asp313, Ala317, Ile386, Tyr259, and Leu496 of human CYP1A1. The site of metabolism is positioned 5.6 Å from the heme iron at an angle of 105.3°. Binding in the active site is stabilized by H-bonding between Tyr259 and the N(2) position of the imidazole ring. Twenty-seven CYP1A1 mutants were generated and expressed in Escherichia coli in yields ranging from 9 to 225 pmol P450/mg. DTIC N-demethylation by the E161K, E256K, and I458V mutants exhibited Michaelis-Menten kinetics, with decreases in K(m) (183-249 μM) that doubled the catalytic efficiency (p < 0.05) relative to wild-type CYP1A1 (K(m), 408 ± 43 μM; V(max), 28 ± 4 pmol · min(-1) · pmol of P450(-1)). The generation of enzymes with catalytically enhanced DTIC activation highlights the potential use of mutant CYP1A1 proteins in P450-based gene-directed enzyme prodrug therapy for the treatment of metastatic malignant melanoma.
Collapse
Affiliation(s)
- Benjamin C Lewis
- Department of Clinical Pharmacology, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, SA 5042, Australia
| | | | | |
Collapse
|
42
|
Has the era of individualised medicine arrived for antifungals? A review of antifungal pharmacogenomics. Bone Marrow Transplant 2011; 47:881-94. [DOI: 10.1038/bmt.2011.146] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
43
|
Li X, Quigg RJ, Zhou J, Gu W, Nagesh Rao P, Reed EF. Clinical utility of microarrays: current status, existing challenges and future outlook. Curr Genomics 2011; 9:466-74. [PMID: 19506735 PMCID: PMC2691672 DOI: 10.2174/138920208786241199] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 08/11/2008] [Accepted: 08/14/2008] [Indexed: 12/22/2022] Open
Abstract
Microarray-based clinical tests have become powerful tools in the diagnosis and treatment of diseases. In contrast to traditional DNA-based tests that largely focus on single genes associated with rare conditions, microarray-based tests are ideal for the study of diseases with underlying complex genetic causes. Several microarray based tests have been translated into clinical practice such as MammaPrint and AmpliChip CYP450. Additional cancer-related microarray-based tests are either in the process of FDA review or under active development, including Tissue of Tumor Origin and AmpliChip p53. All diagnostic microarray testing is ordered by physicians and tested by a Clinical Laboratories Improvement Amendment-certified (CLIA) reference laboratory. Recently, companies offering consumer based microarray testing have emerged. Individuals can order tests online and service providers deliver the results directly to the clients via a password-protected secure website. Navigenics, 23andMe and deCODE Genetics represent pioneering companies in this field. Although the progress of these microarray-based tests is extremely encouraging with the potential to revolutionize the recognition and treatment of common diseases, these tests are still in their infancy and face technical, clinical and marketing challenges. In this article, we review microarray-based tests which are currently approved or under review by the FDA, as well as the consumer-based testing. We also provide a summary of the challenges and strategic solutions in the development and clinical use of the microarray-based tests. Finally, we present a brief outlook for the future of microarray-based clinical applications.
Collapse
Affiliation(s)
- Xinmin Li
- Clinical Microarray Core, Department of Pathology & Laboratory Medicine, University of California at Los Angeles, 1000 Veteran Ave., Los Angeles, CA 90095, USA
| | | | | | | | | | | |
Collapse
|
44
|
Khan N, Pande V, Das A. Characterization, comparative genomics, and evolutionary inferences of a human drug metabolizing (NAT2) gene. Interv Med Appl Sci 2011. [DOI: 10.1556/imas.3.2011.2.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Aim
The present-day genetic architecture of a species bears much significance to its closely related species. In recent availability of whole genome sequence data for closely related species, it is possible to detect genetic similarities/differences in specific lineages and infer the role of evolutionary forces in bringing such similarities/differences. In this respect, NAT2 gene, responsible for drug metabolism, is conserved across a few taxa and, thus, comparative genomic studies could be useful for better pharmacogenetic realization.
Methods
DNA sequences of human NAT2 gene were retrieved from NCBI and characterized. Comparative and evolutionary analyses were performed with sequences from four mammalian taxa and one avian taxon with different statistical algorithms.
Results
The observed genetic architecture of NAT2 gene was different across the taxa. Phylogenetic inferences revealed that human and chimpanzee are diverged recently and fowl was found to be diverged from rest of the taxa significantly. Also, gene length, microsatellites, Ka/Ks, secondary structure, and distribution of CpG islands were observed across taxa.
Conclusions
The detail architecture of NAT2 gene and its evolutionary history in different taxa show relationships with other taxa. Future population-based study in NAT2 would unravel the correlation between nucleotide changes and differential ability of drug metabolization in humans.
Collapse
Affiliation(s)
- Naazneen Khan
- 1 Evolutionary Genomics and Bioinformatics Laboratory, Division of Genomics and Bioinformatics, National Institute of Malaria Research, Dwarka, New Delhi, India
| | - Veena Pande
- 2 Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, India
| | - Aparup Das
- 1 Evolutionary Genomics and Bioinformatics Laboratory, Division of Genomics and Bioinformatics, National Institute of Malaria Research, Dwarka, New Delhi, India
- 3 Evolutionary Genomics and Bioinformatics Laboratory, Division of Genomics and Bioinformatics, National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India
| |
Collapse
|
45
|
Campayo M, Viñolas N, Navarro A, Carcereny E, Casas F, Gel B, Diaz T, Gimferrer JM, Marrades RM, Ramirez J, Monzo M. Single nucleotide polymorphisms in tobacco metabolism and DNA repair genes and prognosis in resected non-small-cell lung cancer. J Surg Res 2011; 167:e5-12. [PMID: 21324488 DOI: 10.1016/j.jss.2011.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 12/09/2010] [Accepted: 01/04/2011] [Indexed: 11/26/2022]
Abstract
BACKGROUND If tobacco-related carcinogens are not inactivated or extruded from the cell, they can damage the DNA. Single nucleotide polymorphisms (SNPs) in genes involved in tobacco metabolism, DNA repair, and multidrug resistance have been related to lung cancer susceptibility. We examined 13 SNPs in 10 of these genes and correlated the results with time to progression (TTP) and overall survival (OS) in 71 smoker or former smoker patients with resected non-small-cell lung cancer (NSCLC). MATERIALS AND METHODS DNA was obtained from paraffin-embedded tumor. SNP analysis of the candidate genes was performed by allelic discrimination assay. Log-rank test, Kaplan-Meier plots, and Cox multivariate analysis were used to evaluate the association of TTP and survival with the SNPs evaluated. RESULTS Patients with wild-type (wt) XPC rs2228001, wt CYP2C8 rs10509681, or non-wt NAT2 rs1799930 had a longer TTP. Patients with wt ERCC1 showed a nonsignificant trend towards longer TTP. No other relation between SNPs and TTP were observed. Patients harboring at least two unfavorable genotypes in these four genes had a shorter TTP and OS than patients with either one or no unfavorable genotypes. In the multivariate analysis, non-wt XPC rs2228001 and the presence of at least two unfavorable genotypes emerged as independent markers for shorter TTP. CONCLUSIONS SNPs in tobacco metabolism and DNA repair genes may influence the clinical outcome of resected NSCLC.
Collapse
Affiliation(s)
- Marc Campayo
- Department of Medical Oncology, ICMHO, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Population pharmacokinetic analysis of glimepiride with CYP2C9 genetic polymorphism in healthy Korean subjects. Eur J Clin Pharmacol 2011; 67:889-98. [PMID: 21476064 DOI: 10.1007/s00228-011-1035-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 03/07/2011] [Indexed: 10/18/2022]
Abstract
PURPOSE The purpose of this study was to develop a population pharmacokinetic (PPK) model of glimepiride and to investigate the influence of genetic polymorphisms in CYP2C9 on the PPK of glimepiride in healthy Korean subjects. METHODS Serum data after a single oral dose of 2 mg of glimepiride in 177 healthy male Korean subjects (CYP2C9*1*1: 163 subjects, *1/*3: 14 subjects) were used. We estimated the PPK of glimepiride using a nonlinear mixed effects modeling (NONMEM) method and explored the possible influence of genetic polymorphisms in CYP2C9 on the PPK of glimepiride. RESULTS The disposition of glimepiride was best described with a two-compartment model with a Weibull-type absorption and first-order elimination. The visual predictive check indicated that the pharmacokinetic profile of glimepiride was adequately described by the proposed PPK model. The CYP2C9 genotypes as covariate significantly (P < 0.001) influenced the apparent oral clearance (CL/F) of glimepiride. The estimated CL/F of glimepiride was higher (1.60-fold) in CYP2C9*1/*1 subjects than in CYP2C9*1/*3 subjects. CONCLUSIONS This study indicates that genetic polymorphisms of CYP2C9 influence the substantial interindividual variability in the disposition of glimepiride, and these polymorphisms may affect the clinical response to glimepiride therapy.
Collapse
|
47
|
Jordan BR. Is there a niche for DNA microarrays in molecular diagnostics? Expert Rev Mol Diagn 2011; 10:875-82. [PMID: 20964608 DOI: 10.1586/erm.10.74] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
DNA microarrays, 15 years after their appearance, have achieved presence in a number of medical settings. Several tests have been introduced and have obtained regulatory approval, mostly in the fields of bacterial identification, mutation detection and the global assessment of genome alterations, a particularly successful case being the whole-genome assay of copy-number variations. Gene-expression applications have been less successful because of technical issues (e.g., reproducibility, platform-to-platform consistency and statistical issues in data analysis) and difficulties in demonstrating the clinical utility of expression signatures. In their different applications, DNA arrays have faced competition from PCR-based assays for low and intermediate multiplicity. Now they have a new competitor, new-generation sequencing, that can provide a wealth of direct sequence information, or digital gene-expression data, at a constantly decreasing cost. In this article we evaluate the strengths and weaknesses of the DNA microarray approach to diagnostics, and highlight the fields in which it is most likely to achieve a durable presence.
Collapse
Affiliation(s)
- Bertrand R Jordan
- Marseille-Nice Genopole, Case 906, Luminy Science Park, 13288 Marseille Cedex 9, France.
| |
Collapse
|
48
|
|
49
|
Guengerich FP, Sohl CD, Chowdhury G. Multi-step oxidations catalyzed by cytochrome P450 enzymes: Processive vs. distributive kinetics and the issue of carbonyl oxidation in chemical mechanisms. Arch Biochem Biophys 2010; 507:126-34. [PMID: 20804723 DOI: 10.1016/j.abb.2010.08.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 08/23/2010] [Accepted: 08/24/2010] [Indexed: 11/17/2022]
Abstract
Catalysis of sequential oxidation reactions is not unusual in cytochrome P450 (P450) reactions, not only in steroid metabolism but also with many xenobiotics. One issue is how processive/distributive these reactions are, i.e., how much do the "intermediate" products dissociate. Our work with human P450s 2E1, 2A6, and 19A1 on this subject has revealed a mixture of systems, surprisingly with a more distributive mechanism with an endogenous substrate (P450 19A1) than for some xenobiotics (P450s 2E1, 2A6). One aspect of this research involves carbonyl intermediates, and the choice of catalytic mechanism is linked to the hydration state of the aldehyde. The non-enzymatic rates of hydration and dehydration of carbonyls are not rapid and whether P450s catalyze the reversible hydration is unknown. If carbonyl hydration and dehydration are slow, the mechanism may be set by the carbonyl hydration status.
Collapse
Affiliation(s)
- F Peter Guengerich
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.
| | | | | |
Collapse
|
50
|
Abstract
Pharmacogenomics, the study of specific genetic variations and their effect on drug response, will likely give rise to many applications in maternal-fetal and neonatal medicine; yet, an understanding of these applications in the field of obstetrics and gynecology and neonatal pediatrics is not widespread. This review describes the underpinnings of the field of pharmacogenomics and summarizes the current pharmacogenomic inquiries in relation to maternal-fetal medicine-including studies on various fetal and neonatal genetic cytochrome P450 (CYP) enzyme variants and their role in drug toxicities (for example, codeine metabolism, sepsis and selective serotonin reuptake inhibitor (SSRI) toxicity). Potential future directions, including alternative drug classification, improvements in drug efficacy and non-invasive pharmacogenomic testing, will also be explored.
Collapse
|