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Lucena MI, Villanueva-Paz M, Alvarez-Alvarez I, Aithal GP, Björnsson ES, Cakan-Akdogan G, Cubero FJ, Esteves F, Falcon-Perez JM, Fromenty B, Garcia-Ruiz C, Grove JI, Konu O, Kranendonk M, Kullak-Ublick GA, Miranda JP, Remesal-Doblado A, Sancho-Bru P, Nelson L, Andrade RJ, Daly AK, Fernandez-Checa JC. Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet. Pharmacol Res 2024; 200:107046. [PMID: 38159783 DOI: 10.1016/j.phrs.2023.107046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.
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Affiliation(s)
- M I Lucena
- Servicios de Aparato Digestivo y Farmacología Clínica, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Universidad de Málaga, Málaga, Spain; Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain; Plataforma de Investigación Clínica y Ensayos Clínicos UICEC-IBIMA, Plataforma ISCIII de Investigación Clínica, Madrid, Spain.
| | - M Villanueva-Paz
- Servicios de Aparato Digestivo y Farmacología Clínica, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Universidad de Málaga, Málaga, Spain; Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain
| | - I Alvarez-Alvarez
- Servicios de Aparato Digestivo y Farmacología Clínica, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Universidad de Málaga, Málaga, Spain; Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain
| | - G P Aithal
- Nottingham Digestive Diseases Centre, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom; NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, United Kingdom
| | - E S Björnsson
- Faculty of Medicine, University of Iceland, Department of Gastroenterology and Hepatology, Landspitali University Hospital, Reykjavik, Iceland
| | - G Cakan-Akdogan
- Izmir Biomedicine and Genome Center, Izmir, Turkey. Department of Medical Biology, Faculty of Medicine, Dokuz Eylül University, Izmir, Turkey
| | - F J Cubero
- Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain; Department of Immunology, Ophthalmology and ORL, Complutense University School of Medicine, Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - F Esteves
- Center for Toxicogenomics and Human Health (ToxOmics), NMS | FCM, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - J M Falcon-Perez
- Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain; Exosomes Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Derio, Bizkaia, 48160, Spain. IKERBASQUE, Basque Foundation for Science, Bilbao, Bizkaia 48009, Spain
| | - B Fromenty
- INSERM, Univ Rennes, INRAE, Institut NUMECAN (Nutrition Metabolisms and Cancer) UMR_A 1341, UMR_S 1317, F-35000 Rennes, France
| | - C Garcia-Ruiz
- Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. University of Barcelona, Barcelona, Spain; Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain
| | - J I Grove
- Nottingham Digestive Diseases Centre, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom; NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, United Kingdom
| | - O Konu
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey; Interdisciplinary Neuroscience Program, Bilkent University, Ankara, Turkey; UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey
| | - M Kranendonk
- Center for Toxicogenomics and Human Health (ToxOmics), NMS | FCM, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - G A Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland; CMO & Patient Safety, Global Drug Development, Novartis Pharma, Basel, Switzerland
| | - J P Miranda
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - A Remesal-Doblado
- Servicios de Aparato Digestivo y Farmacología Clínica, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Universidad de Málaga, Málaga, Spain
| | - P Sancho-Bru
- Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. University of Barcelona, Barcelona, Spain
| | - L Nelson
- Institute for Bioengineering, School of Engineering, Faraday Building, The University of Edinburgh, Scotland, UK
| | - R J Andrade
- Servicios de Aparato Digestivo y Farmacología Clínica, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Universidad de Málaga, Málaga, Spain; Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain
| | - A K Daly
- Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - J C Fernandez-Checa
- Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. University of Barcelona, Barcelona, Spain; Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain; Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Daly AK. Direct-to-consumer pharmacogenomic testing assessed in a US-based study. J R Coll Physicians Edinb 2014; 44:212-3. [PMID: 25318397 DOI: 10.4997/jrcpe.2014.305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- A K Daly
- A Daly, Institute of Cellular Medicine, Newcastle University, WIlliam Leech Builiding, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK. Email
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Maitland-van der Zee AH, Daly AK, Kamali F, Manolopoulous VG, Manolopoulos VG, Verhoef TI, Wadelius M, de Boer A, Pirmohamed M. Patients benefit from genetics-guided coumarin anticoagulant therapy. Clin Pharmacol Ther 2014; 96:15-7. [PMID: 24942396 DOI: 10.1038/clpt.2014.44] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Observational studies have overwhelmingly shown that variants in the genes CYP2C9 and VKORC1 are significant determinants of individual dose of coumarin anticoagulants needed to maintain a therapeutic international normalized ratio (INR).(1) Until recently, however, few randomized clinical trials had been performed relating to the use of genetic data to predict dosing. Three sucsh clinical trials have now reported their findings.
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Affiliation(s)
- A H Maitland-van der Zee
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - A K Daly
- Institute of Cellular Medicine, Newcastle University Medical School, Newcastle upon Tyne, UK
| | - F Kamali
- Institute of Cellular Medicine, Newcastle University Medical School, Newcastle upon Tyne, UK
| | | | - V G Manolopoulos
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - T I Verhoef
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - M Wadelius
- Department of Medical Sciences, Clinical Pharmacology, Uppsala University, Uppsala, Sweden
| | - A de Boer
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - M Pirmohamed
- The Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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Liu YL, Patman GL, Leathart JBS, Piguet AC, Burt AD, Dufour JF, Day CP, Daly AK, Reeves HL, Anstee QM. Carriage of the PNPLA3 rs738409 C >G polymorphism confers an increased risk of non-alcoholic fatty liver disease associated hepatocellular carcinoma. J Hepatol 2014; 61:75-81. [PMID: 24607626 DOI: 10.1016/j.jhep.2014.02.030] [Citation(s) in RCA: 355] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 02/26/2014] [Accepted: 02/27/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Subtle inter-patient genetic variation and environmental factors combine to determine disease progression in non-alcoholic fatty liver disease (NAFLD). Carriage of the PNPLA3 rs738409 c.444C >G minor allele (encoding the I148M variant) has been robustly associated with advanced NAFLD. Although most hepatocellular carcinoma (HCC) is related to chronic viral hepatitis or alcoholic liver disease, the incidence of NAFLD-related HCC is increasing. We examined whether rs738409 C >G was associated with HCC-risk in patients with NAFLD. METHODS PNPLA3 rs738409 genotype was determined by allelic discrimination in 100 European Caucasians with NAFLD-related HCC and 275 controls with histologically characterised NAFLD. RESULTS Genotype frequencies were significantly different between NAFLD-HCC cases (CC=28, CG=43, GG=29) and NAFLD-controls (CC=125, CG=117, GG=33) (p=0.0001). In multivariate analysis adjusted for age, gender, diabetes, BMI, and presence of cirrhosis, carriage of each copy of the rs738409 minor (G) allele conferred an additive risk for HCC (adjusted OR 2.26 [95% CI 1.23-4.14], p=0.0082), with GG homozygotes exhibiting a 5-fold [1.47-17.29], p=0.01 increased risk over CC. When compared to the UK general population (1958 British Birth Cohort, n=1476), the risk-effect was more pronounced (GC vs. CC: unadjusted OR 2.52 [1.55-4.10], p=0.0002; GG vs. CC: OR 12.19 [6.89-21.58], p<0.0001). CONCLUSIONS Carriage of the PNPLA3 rs738409 C >G polymorphism is not only associated with greater risk of progressive steatohepatitis and fibrosis but also of HCC. If validated, these findings suggest that PNPLA3 genotyping has the potential to contribute to multi-factorial patient-risk stratification, identifying those to whom HCC surveillance may be targeted.
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Affiliation(s)
- Y-L Liu
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - G L Patman
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - J B S Leathart
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - A-C Piguet
- University Clinic of Visceral Surgery and Medicine, Inselspital Bern, Bern, Switzerland
| | - A D Burt
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - J-F Dufour
- University Clinic of Visceral Surgery and Medicine, Inselspital Bern, Bern, Switzerland
| | - C P Day
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - A K Daly
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - H L Reeves
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Newcastle upon Tyne, UK.
| | - Q M Anstee
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne, UK
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Illingworth NA, Boddy AV, Daly AK, Veal GJ. Characterization of the metabolism of fenretinide by human liver microsomes, cytochrome P450 enzymes and UDP-glucuronosyltransferases. Br J Pharmacol 2011; 162:989-99. [PMID: 21054342 PMCID: PMC3042207 DOI: 10.1111/j.1476-5381.2010.01104.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Fenretinide (4-HPR) is a retinoic acid analogue, currently used in clinical trials in oncology. Metabolism of 4-HPR is of particular interest due to production of the active metabolite 4'-oxo 4-HPR and the clinical challenge of obtaining consistent 4-HPR plasma concentrations in patients. Here, we assessed the enzymes involved in various 4-HPR metabolic pathways. EXPERIMENTAL APPROACH Enzymes involved in 4-HPR metabolism were characterized using human liver microsomes (HLM), supersomes over-expressing individual human cytochrome P450s (CYPs), uridine 5'-diphospho-glucoronosyl transferases (UGTs) and CYP2C8 variants expressed in Escherichia coli. Samples were analysed by high-performance liquid chromatography and liquid chromatography/mass spectrometry assays and kinetic parameters for metabolite formation determined. Incubations were also carried out with inhibitors of CYPs and methylation enzymes. KEY RESULTS HLM were found to predominantly produce 4'-oxo 4-HPR, with an additional polar metabolite, 4'-hydroxy 4-HPR (4'-OH 4-HPR), produced by individual CYPs. CYPs 2C8, 3A4 and 3A5 were found to metabolize 4-HPR, with metabolite formation prevented by inhibitors of CYP3A4 and CYP2C8. Differences in metabolism to 4'-OH 4-HPR were observed with 2C8 variants, CYP2C8*4 exhibited a significantly lower V(max) value compared with *1. Conversely, a significantly higher V(max) value for CYP2C8*4 versus *1 was observed in terms of 4'-oxo formation. In terms of 4-HPR glucuronidation, UGTs 1A1, 1A3 and 1A6 produced the 4-HPR glucuronide metabolite. CONCLUSIONS AND IMPLICATIONS The enzymes involved in 4-HPR metabolism have been characterized. The CYP2C8 isoform was found to have a significant effect on oxidative metabolism and may be of clinical relevance.
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Affiliation(s)
- N A Illingworth
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
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Dongiovanni P, Valenti L, Rametta R, Daly AK, Nobili V, Mozzi E, Leathart JBS, Pietrobattista A, Burt AD, Maggioni M, Fracanzani AL, Lattuada E, Zappa MA, Roviaro G, Marchesini G, Day CP, Fargion S. Genetic variants regulating insulin receptor signalling are associated with the severity of liver damage in patients with non-alcoholic fatty liver disease. Gut 2010; 59:267-73. [PMID: 20176643 DOI: 10.1136/gut.2009.190801] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND/AIMS The aim of this study was to assess the effect of functional ENPP1(ectoenzyme nucleotide pyrophosphate phosphodiesterase 1)/PC-1 (plasma cell antigen-1) and IRS-1 (insulin receptor substrate-1) polymorphisms influencing insulin receptor activity on liver damage in non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, whose progression is associated with the severity of insulin resistance. PATIENTS AND METHODS 702 patients with biopsy-proven NAFLD from Italy and the UK, and 310 healthy controls. The Lys121Gln ENPP1/PC-1 and the Gly972Arg IRS-1 polymorphisms were evaluated by restriction analysis. Fibrosis was evaluated according to Kleiner. Insulin signalling activity was evaluated by measuring phosphoAKT levels by western blotting in a subset of obese non-diabetic patients. RESULTS The ENPP1 121Gln and IRS-1 972Arg polymorphisms were detected in 28.7% and 18.1% of patients and associated with increased body weight/dyslipidaemia and diabetes risk, respectively. The ENPP1 121Gln allele was significantly associated with increased prevalence of fibrosis stage >1 and >2, which was higher in subjects also positive for the 972Arg IRS-1 polymorphism. At multivariate analysis, the presence of the ENPP1 121Gln and IRS-1 972Arg polymorphisms was independently associated with fibrosis >1 (OR 1.55, 95% CI 1.24 to 1.97; and OR 1.57, 95% CI 1.12 to 2.23, respectively). Both polymorphisms were associated with a marked reduction of approximately 70% of AKT activation status, reflecting insulin resistance and disease severity, in obese patients with NAFLD. CONCLUSIONS The ENPP1 121Gln and IRS-1 972Arg polymorphisms affecting insulin receptor activity predispose to liver damage and decrease hepatic insulin signalling in patients with NAFLD. Defective insulin signalling may play a causal role in the progression of liver damage in NAFLD.
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Affiliation(s)
- P Dongiovanni
- Università degli Studi Milano, Policlinico MaRE IRCCS Hospital, Milan, Italy
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Abstract
BACKGROUND The strongest risk factors for pancreatic adenocarcinoma are tobacco smoking and increasing age. However, only a few smokers or elderly individuals develop the disease and genetic factors are also likely to be important. METHODS The literature on genetic factors modifying susceptibility to cancer was reviewed, with particular regard to the interindividual variation that exists in the development of pancreatic adenocarcinoma. RESULTS Tobacco-derived carcinogen-metabolizing enzyme gene variants have been the main area of study in stratifying the risk of sporadic pancreatic cancer. Inconsistent results have emerged from the few molecular epidemiological studies performed. CONCLUSION There is great scope for further investigation of critical pathways and unidentified genetic influences may be revealed. This may eventually allow the identification of individuals at high risk who might be targeted for screening.
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Affiliation(s)
- R Lochan
- Hepato-Pancreato-Biliary Unit, Department of Surgery, Freeman Hospital, Newcastle upon Tyne, UK.
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Bermano G, Pagmantidis V, Holloway N, Kadri S, Mowat NAG, Shiel RS, Arthur JR, Mathers JC, Daly AK, Broom J, Hesketh JE. Evidence that a polymorphism within the 3'UTR of glutathione peroxidase 4 is functional and is associated with susceptibility to colorectal cancer. Genes Nutr 2007; 2:225-32. [PMID: 18850177 DOI: 10.1007/s12263-007-0052-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Accepted: 01/18/2007] [Indexed: 11/24/2022]
Abstract
Low selenium (Se) status has been associated with increased risk of colorectal cancer (CRC). Se is present as the amino acid selenocysteine in selenoproteins, such as the glutathione peroxidases. Se incorporation requires specific RNA structures in the 3' untranslated region (3'UTR) of the selenoprotein mRNAs. A single nucleotide polymorphism (SNP) occurs at nucleotide 718 (within the 3'UTR) in the glutathione peroxidase 4 gene. In the present study, Caco-2 cells were transfected with constructs in which type 1 iodothyronine deiodinase coding region was linked to the GPx4 3'UTR with either C or T variant at position 718. Higher reporter activity was observed in cells expressing the C variant compared to those expressing the T variant, under either Se-adequate or Se-deficient conditions. In addition, a disease association study was carried out in cohorts of patients with either adenomatous polyps, colorectal adenocarcinomas and in healthy controls. A higher proportion of individuals with CC genotype at the GPx4 T/C 718 SNP was present in the cancer group, but not in the polyp group, compared with the control group (P < 0.05). The present data demonstrate the functionality of the GPx4 T/C 718 SNP and suggest that T genotype is associated with lower risk of CRC.
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Affiliation(s)
- G Bermano
- School of Life Sciences, The Robert Gordon University, Aberdeen, AB25 1HG, UK
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Thanacoody RHK, Daly AK, Reilly JG, Ferrier IN, Thomas SHL. Factors affecting drug concentrations and QT interval during thioridazine therapy. Clin Pharmacol Ther 2007; 82:555-65. [PMID: 17460606 DOI: 10.1038/sj.clpt.6100195] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The objective of this study was to investigate factors affecting steady-state plasma concentrations of thioridazine. A cross-sectional study of patients receiving chronic thioridazine was employed. Common allelic variants of CYP2D6 and CYP2C19, as well as thioridazine and metabolite concentrations and QTc intervals, were determined. In 97 patients, dose-corrected plasma concentrations (C/Ds) of thioridazine and metabolites were correlated with age but not sex or CYP2C19 genotype. Patients with no functional CYP2D6 alleles (n=9) had significantly higher C/D for thioridazine (P=0.017) and the ring sulfoxide metabolite and a significantly higher thioridazine/mesoridazine ratio compared with those with >/=1 functional CYP2D6 allele (n=82). Smokers had significantly lower C/D for thioridazine, mesoridazine, and sulforidazine and significantly lower thioridazine/ring sulfoxide ratios than non-smokers. QTc interval was not significantly affected by CYP2D6 or CYP2C19 genotypes. Plasma concentrations of thioridazine are influenced by age, smoking, and CYP2D6 genotype, but CYP2D6 genotype does not appear to influence on-treatment QTc interval.
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Affiliation(s)
- R H K Thanacoody
- School of Clinical and Laboratory Sciences, University of Newcastle, Newcastle upon Tyne, UK
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Todhunter CE, Sutherland-Craggs A, Bartram SA, Donaldson PT, Daly AK, Francis RM, Mansfield JC, Thompson NP. Influence of IL-6, COL1A1, and VDR gene polymorphisms on bone mineral density in Crohn's disease. Gut 2005; 54:1579-84. [PMID: 16009674 PMCID: PMC1774753 DOI: 10.1136/gut.2005.064212] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Osteoporosis is an important cause of morbidity in patients with Crohn's disease. The pathogenesis of reduced bone mineral density (BMD) is multifactorial. A range of genetic factors have been implicated in other populations of patients with osteoporosis. AIM To investigate the influence of interleukin 6 (IL-6), collagen type 1alpha1 (COL1A1), and vitamin D receptor gene (VDR) single nucleotide polymorphisms (SNP) on BMD in patients with Crohn's disease. PATIENTS A cohort of 245 well characterised patients with Crohn's disease were recruited from the inflammatory bowel disease register at the Freeman Hospital and Royal Victoria Infirmary, Newcastle upon Tyne, and the Queen Elizabeth Hospital, Gateshead, UK. METHODS Patients were genotyped for IL-6 C-174G SNP, COL1A1 Sp1 binding site G T SNP, VDR Taq1, and Fok1 SNPs, and CARD15 R702W, G908R, and L1007fs SNPs. BMD was measured at the lumbar spine (LSP) and hip using dual energy x ray absorptiometry. RESULTS A total of 158 female and 87 male patients, aged 24-70 years (mean 44), were recruited. There were no significant differences in the distribution of the tested SNPs when analysed for age, body mass index, pre/post-menopausal status, smoking, or steroid use. Two hundred and thirteen patients were genotyped for the IL-6 SNP. LSP and total hip BMD was significantly lower in patients with the GG genotype (48%) than the CC genotype (15%) (p = 0.041, p = 0.014). One hundred and eighty patients were genotyped for the COL1A1 SNP. There was no significant difference in BMD at LSP. Hip BMD was significantly lower in heterozygous patients compared with homozygous wild-types (p = 0.034). There were no significant differences in BMD between genotypes for the two VDR SNPs or the CARD15 genotypes examined. CONCLUSION IL-6 and COL1A1 gene polymorphisms influence BMD in patients with Crohn's disease but the particular VDR gene polymorphisms studied do not have a major effect.
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Affiliation(s)
- C E Todhunter
- Department of Medicine, Freeman Hospital, High Heaton, Newcastle Upon Tyne, NE7 7DN, UK
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Malhi H, Atac B, Daly AK, Gupta S. Warfarin and celecoxib interaction in the setting of cytochrome P450 (CYP2C9) polymorphism with bleeding complication. Postgrad Med J 2004; 80:107-9. [PMID: 14970301 PMCID: PMC1742931 DOI: 10.1136/pmj.2003.006478] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Drug metabolism may be perturbed by genetically determined differences in the metabolic activity of cytochrome P450 enzymes. The authors encountered extensive bleeding in a patient receiving warfarin for anticoagulation after the introduction of celecoxib, an anti-inflammatory drug. As the CYP2C9 enzyme metabolises these drugs, it was determined whether variant alleles were responsible for altering warfarin handling. Genetic analysis established that the patient was a compound heterozygote with CYP2C9*2 and *3 variant alleles, which exhibit lower drug metabolising capacity and enhance susceptibility to drug toxicity.
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Affiliation(s)
- H Malhi
- Marion Bessin Liver Research Center and Department of Medicine, Albert Einstein College of Medicine, New York, USA
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Abstract
There is increasing information available on the existence of polymorphisms in genes encoding xenobiotic metabolizing enzymes and the functional significance of many of these. In addition to genes long recognized as being polymorphic, such as CYP2D6, CYP2C19 and CYP2C9, there is now information available on the existence of polymorphisms in other cytochrome P450 genes such as CYP2A6, CYP2B6 and CYP2C8. With respect to phase II metabolism, polymorphisms in GSTM1, GSTT1, NAT2 and TPMT are well understood but information is also emerging on other GST polymorphisms and on polymorphisms in the UDP-glucuronosyltransferases and sulfotransferases. The availability of comprehensive information on the occurrence and functional significance of polymorphisms affecting drug metabolism should facilitate their application to pharmacogenomic profiling.
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Affiliation(s)
- A K Daly
- Department of Pharmacological Sciences, University of Newcastle, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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16
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Ingelman-Sundberg M, Oscarson M, Daly AK, Garte S, Nebert DW. Human cytochrome P-450 (CYP) genes: a web page for the nomenclature of alleles. Cancer Epidemiol Biomarkers Prev 2001; 10:1307-8. [PMID: 11751452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
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17
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Vineis P, Marinelli D, Autrup H, Brockmoller J, Cascorbi I, Daly AK, Golka K, Okkels H, Risch A, Rothman N, Sim E, Taioli E. Current smoking, occupation, N-acetyltransferase-2 and bladder cancer: a pooled analysis of genotype-based studies. Cancer Epidemiol Biomarkers Prev 2001; 10:1249-52. [PMID: 11751441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
The aim of this study was to investigate the association of NAT2 gene polymorphism with bladder cancer using the data derived from the International Project on Genetic Susceptibility to Environmental Carcinogens. Four case control studies conducted in four European countries, plus two case series, one from England and one from Germany, for a total of 1530 cases and 731 controls (all Caucasian) were included. The interaction between NAT2 and bladder cancer considering smoking habits and occupational exposure was studied. There was a significant association between NAT2 and bladder cancer (odds ratio: 1.42, 95% confidence interval: 1.14-1.77), with a slightly significant heterogeneity among studies. However, heterogeneity disappeared when smokers were divided into current and ex-smokers. The risk of cancer was elevated in smokers and occupationally exposed subjects, with the highest risk among slow acetylators. The increase in risk was limited, in fact, to current smokers (odds ratio = 1.74, 95% confidence interval: 0.96-3.15). This analysis confirms that the NAT2 genotype is a risk factor for bladder cancer by interacting with smoking or occupational exposures. Our observation suggests that NAT2 is not a risk factors per se but modulates the effect of carcinogens contained in tobacco smoke (probably arylamines) or associated with occupational exposures.
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Affiliation(s)
- P Vineis
- CPO-Piemonte at the University of Torino, Torino, Italy
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18
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Abstract
There is increasing information on the importance of genetic polymorphisms in human genes. Polymorphisms occur on average once every 500-1000 base pairs in the human genome and are useful in the identification of genes involved in human disease. Some genetic polymorphisms have functionally significant effects on the gene product and are the most useful type of polymorphism in disease association studies while others are simply useful markers. There are two main approaches using polymorphisms in the identification of genes involved in polygenic diseases. The first involves examining inheritance patterns for genetic polymorphisms in family studies and the second case-control studies which compare genotype frequencies for candidate disease genes in unrelated individuals with the disease and healthy controls. Use of family studies is generally the preferred approach but this is only feasible if the genetic component of the disease is relatively strong, DNA samples are available from other family members and the disease is relatively easy to diagnose and is not stigmatized. Population case-control studies are useful both as an alternative and an adjunct to family studies. When performing case-control studies factors such as study design, methods for recruitment of cases and controls, functional significance of polymorphisms chosen for study and statistical analysis of data require close attention to ensure that only genuine associations are detected. To illustrate some potential problems in the design and interpretation of association studies, some specific examples of association studies on drug response and on disease susceptibility involving receptor genes, cytochrome P450 and other xenobiotic metabolizing enzyme genes and immune system genes including TNF-alpha, IL-10 and the IL-4 receptor are discussed.
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Affiliation(s)
- A K Daly
- Centre for Liver Research, University of Newcastle upon Tyne, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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19
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Aithal GP, Craggs A, Day CP, Welfare M, Daly AK, Mansfield JC, Hudson M. Role of polymorphisms in the interleukin-10 gene in determining disease susceptibility and phenotype in inflamatory bowel disease. Dig Dis Sci 2001. [PMID: 11478505 DOI: 10.1023/a: 1010604307776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Interleukin-10 (IL-10) has a key role in regulating mucosal inflammation. The role of functional polymorphisms at positions -627 and -1117 in the IL-10 gene as candidate susceptibility loci in inflammatory bowel disease and their importance in determining disease extent were evaluated in 159 patients with ulcerative colitis (83 left-sided; 76 extensive), 90 patients with Crohn's disease (22 small bowel; 29 large bowel; 39 both), and 227 controls. Genotyping was performed either by PCR-RFLP assays (-627 site) or SSCP analysis (-1117 site). An excess of -627A allele was observed in patients with left-sided colitis (52%) compared with controls (33%; P = 0.004) suggesting that IL-10 may influence the extent of the disease. These results were not replicated in a newly recruited group (N = 100) of patients with UC. We conclude that polymorphisms at -627 and -1117 sites in the IL-10 gene do not contribute to the susceptibility to IBD or determining the extent of the disease in our population.
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Affiliation(s)
- G P Aithal
- Department of Medicine, Medical School, University of Newcastle, Newcastle upon Tyne, UK
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20
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Abstract
The main genetic polymorphisms affecting the metabolism and transport of cytotoxic drugs are discussed in this review. Likely future approaches to pharmacogenetics and emerging technologies, such as tumor classification using microarray analysis, are also considered.
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Affiliation(s)
- A K Daly
- Department of Pharmacological Sciences, University of Newcastle Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
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21
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Aithal GP, Craggs A, Day CP, Welfare M, Daly AK, Mansfield JC, Hudson M. Role of polymorphisms in the interleukin-10 gene in determining disease susceptibility and phenotype in inflamatory bowel disease. Dig Dis Sci 2001; 46:1520-5. [PMID: 11478505 DOI: 10.1023/a:1010604307776] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Interleukin-10 (IL-10) has a key role in regulating mucosal inflammation. The role of functional polymorphisms at positions -627 and -1117 in the IL-10 gene as candidate susceptibility loci in inflammatory bowel disease and their importance in determining disease extent were evaluated in 159 patients with ulcerative colitis (83 left-sided; 76 extensive), 90 patients with Crohn's disease (22 small bowel; 29 large bowel; 39 both), and 227 controls. Genotyping was performed either by PCR-RFLP assays (-627 site) or SSCP analysis (-1117 site). An excess of -627A allele was observed in patients with left-sided colitis (52%) compared with controls (33%; P = 0.004) suggesting that IL-10 may influence the extent of the disease. These results were not replicated in a newly recruited group (N = 100) of patients with UC. We conclude that polymorphisms at -627 and -1117 sites in the IL-10 gene do not contribute to the susceptibility to IBD or determining the extent of the disease in our population.
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Affiliation(s)
- G P Aithal
- Department of Medicine, Medical School, University of Newcastle, Newcastle upon Tyne, UK
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22
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Harbottle A, Daly AK, Atherton K, Campbell FC. Role of glutathione S-transferase P1, P-glycoprotein and multidrug resistance-associated protein 1 in acquired doxorubicin resistance. Int J Cancer 2001; 92:777-83. [PMID: 11351295 DOI: 10.1002/ijc.1283] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
While P-glycoprotein (Pgp) and multidrug resistance-associated protein 1 (MRP1) are known to be important in acquired doxorubicin resistance, the role of glutathione S-transferases (GST) remains unclear. Our study assessed roles of these 3 factors in a human drug-sensitive carcinoma cell line (HEp2), a subclone made resistant by prolonged incubation in doxorubicin (HEp2A), and HEp2 cells stably transfected with human GSTP1. Drug-resistant HEp2A cells showed greater total GST activity, GSTP class enzyme expression, Pgp expression, MRP1 transcript expression, drug efflux and at least 13-fold greater resistance to doxorubicin than the parent HEp2 cell line. GSTM class enzyme expression was similar in both cell types, while GSTA class enzymes were not detected. In the resistant HEp2A cells, cytotoxicity was markedly enhanced by the Pgp/MRP inhibitor verapamil at low doxorubicin concentrations. The GST inhibitor curcumin also enhanced cytotoxicity in HEp2A cells when the Pgp/MRP efflux barrier had been reversed by verapamil or overcome by high doxorubicin concentrations. In addition, curcumin had a chemosensitising effect at low doxorubicin concentrations in HEp2 cells. Stable transfection of HEp2 cells with human GSTP1 increases doxorubicin resistance 3-fold over control cells. Our study indicates involvement of GSTP enzymes as well as efflux mechanisms in the acquired doxorubicin-resistance phenotype.
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Affiliation(s)
- A Harbottle
- Department of Surgical Sciences, The Medical School, University of Newcastle, Newcastle upon Tyne, United Kingdom
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Aithal GP, Day CP, Leathart J, Daly AK, Hudson M. Association of single nucleotide polymorphisms in the interleukin-4 gene and interleukin-4 receptor gene with Crohn's disease in a British population. Genes Immun 2001; 2:44-7. [PMID: 11294568 DOI: 10.1038/sj.gene.6363730] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2000] [Revised: 10/16/2000] [Accepted: 11/05/2000] [Indexed: 01/02/2023]
Abstract
Interleukin-4 (IL-4) is an important cytokine in mucosal immunity and plays a critical role in the development of colitis in T-alpha cell receptor mutant mice. Functionally significant polymorphisms have been described in the genes encoding IL-4 and IL-4 receptor. To examine the role of these polymorphisms in disease susceptibility 98 patients with ulcerative colitis, 86 patients with Crohn's disease and 321 healthy controls were genotyped for polymorphisms at position -34 in the IL-4 gene and codon 576 in the IL-4 receptor gene. Thirty-two percent of patients with Crohn's disease carried one or two copies of the variant allele for IL-4 compared with 16% of the controls (P = 0.002). Forty-one percent of patients with Crohn's disease carried one or two copies of the variant IL-4 receptor allele compared with 31% of the controls (P = 0.09). Fifteen percent of patients with Crohn's disease carried combination of both (IL-4 and IL-4 receptor) variant alleles compared with 4% of the controls (P = 0.005). Association with alleles resulting in high IL-4 transcription and enhanced signalling activity suggests that IL-4 may have a role in the pathogenesis of Crohn's disease.
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Affiliation(s)
- G P Aithal
- Centre for Liver Research, Medical School, University of Newcastle upon Tyne, UK.
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Løvlie R, Daly AK, Matre GE, Molven A, Steen VM. Polymorphisms in CYP2D6 duplication-negative individuals with the ultrarapid metabolizer phenotype: a role for the CYP2D6*35 allele in ultrarapid metabolism? Pharmacogenetics 2001; 11:45-55. [PMID: 11207030 DOI: 10.1097/00008571-200102000-00006] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Ultrarapid drug metabolism mediated by CYP2D6 is associated with inheritance of alleles with duplicated or amplified functional CYP2D6 genes. However, genotyping for duplicated CYP2D6 alleles only explains a fraction (10-30%) of the ultrarapid metabolizer phenotypes observed in Caucasian populations. Using a sample of CYP2D6 duplication-negative ultrarapid metabolizer subjects and selected control subjects with extensive metabolism, we examined parts of the CYP2D7 pseudogene, and the promoter region and 5'-coding sequence of CYP2D6 for polymorphisms possibly associated with the ultrarapid metabolizer phenotype. In an initial screening of 17 subjects (13 ultrarapid metabolizers and four extensive metabolizers), we identified three DNA variants in the 5'-end of the CYP2D7 pseudogene and 29 variants in the 5'-end of the CYP2D6 gene. Five variants were then selected for examination in a larger sample of subjects having the ultrarapid metabolizer (n = 27) or extensive metabolizer phenotype (n = 77). Subsequent statistical analyses of allele, genotype and estimated haplotype distributions showed that the 31A allele of the 31G > A (Val(II)Met) polymorphism was significantly more frequent in ultrarapid metabolizer subjects than in extensive metabolizer subjects (P = 0.04). Also, estimation of haplotype frequencies suggested that one of the haplotypes with the 31A variant was significantly more frequent among the ultrarapid metabolizers compared with the extensive metabolizers (P = 0.03). The average metabolic ratio was significantly lower in subjects possessing the 31A allele compared with subjects homozygous for the 31G allele (P = 0.02). We also observed a nonsignificant over-representation of the G-allele of a - 1584 C > G promoter polymorphism in the ultrarapid metabolizer group. Since our results are based on a relatively low number of subjects, further studies on larger samples and functional analyses of the polymorphisms detected are necessary to determine the role of the 31G > A and - 1584C > 6 variants in CYP2D6 duplication-negative ultrarapid metabolizer subjects.
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Affiliation(s)
- R Løvlie
- Dr Einar Martens Research Group for Biological Psychiatry, Haukeland University Hospital and University of Bergen, Norway.
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25
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Abstract
The role of specific human cytochrome P450 (CYP) isoforms in the oxidative metabolism of all-trans-retinoic acid was investigated by studies in human liver microsomes using isoform-specific chemical inhibitors and inhibitory antibodies. Studies using individual isoforms expressed in lymphoblastoid cells and correlation analysis using different microsome preparations were also performed. With expressed isoforms, evidence for a role for CYP2C8, CYP3A4, CYP2C9, and CYP1A1 in 4-hydroxylation was obtained, with the highest catalytic efficiency being observed for CYP2C8. Using inhibition studies and correlation analysis, we also concluded that CYP2C8 was the major all-trans-retinoic acid 4-hydroxylating cytochrome P450 in human liver microsomes, though CYP3A4 and, to a lesser extent CYP2C9, also made a contribution. In addition, we compared the rate of retinoic acid degredation in HepG2 cells when cultured in the absence and presence of 3-methylcholanthrene or all-trans-retinoic acid. Culture in the presence of all-trans-retinoic acid decreased the half-life twofold and resulted in an increased sensitivity of retinoic acid degredation to ketoconazole. Since no induction of either CYP1A1, CYP2C8, CYP2C9, or CYP3A4 was detected using immunoblotting and as mRNA encoding another cytochrome P450 enzyme, CYP26, has been previously demonstrated to be induced by retinoic acid treatment of HepG2 cells and to be highly sensitive to ketoconazole, this enzyme in addition to CYP2C8, CYP2C9 and CYP3A4 likely plays a role in all-trans-retinoic acid oxidation in the liver at high retinoic acid levels.
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Affiliation(s)
- L C McSorley
- Department of Pharmacological Sciences, University of Newcastle upon Tyne, Medical School, Newcastle upon Tyne, UK
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Aithal GP, Day CP, Leathart JB, Daly AK. Relationship of polymorphism in CYP2C9 to genetic susceptibility to diclofenac-induced hepatitis. Pharmacogenetics 2000; 10:511-8. [PMID: 10975605 DOI: 10.1097/00008571-200008000-00004] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The mechanism by which diclofenac-induced hepatotoxicity occurs is unclear, even though covalent modification of proteins by diclofenac metabolites appears to be important in pathogenesis, either by altering protein function or by eliciting an immune response. Adduct formation may be due to metabolism of diclofenac via an alternative pathway rather than via its major 4'-hydroxylation pathway mediated by the cytochrome P450 CYP2C9. We hypothesized that possession of variant CYP2C9 alleles might be a risk factor for diclofenac-induced hepatotoxicity, since the allelic variants CYP2C9*2 and CYP2C9*3 may be associated with impaired metabolism compared to the wild-type (CYP2C9*1). To investigate in more detail the effects of the polymorphisms on diclofenac metabolism in human liver, the kinetics of diclofenac 4-hydroxylation by human liver microsomes of known CYP2C9 >genotype were examined. An overall difference in Vmax and Vmax/Km between samples homozygous for CYP2C9*1 and heterozygous for CYP2C9*2 or CYP2C9*3 was detected (P = 0.044). However, on subgroup analysis, there was no significant difference between samples homozygous for CYP2C9*1 and heterozygous for CYP2C9*2, although there was a borderline difference between the samples homozygous for CYP2C9*1 and those heterozygous for CYP2C9*3 (P = 0.057). The relationship between CYP2C9 genotype and susceptibility to diclofenac-induced hepatotoxicity was further examined by genotyping 24 patients with diclofenac-induced hepatotoxicity together with 100 healthy controls for the CYP2C9*2 and CYP2C9*3 alleles. CYP2C9 genotype frequencies for CYP2C9*2 and CYP2C9*3 were similar in patients and controls. To assess whether diclofenac-induced hepatotoxicity was due to rare CYP2C9 mutations, the upstream sequence (-1 to -1000) and all exons and exon-intron boundaries of CYP2C9 from four subjects who had suffered severe hepatotoxicity was determined. However, no new polymorphisms were detected. We therefore found no evidence that polymorphism in CYP2C9 is a determinant of diclofenac-induced hepatotoxicity.
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Affiliation(s)
- G P Aithal
- Centre for Liver Research, University of Newcastle upon Tyne, Medical School, UK
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Brown MA, Edwards S, Hoyle E, Campbell S, Laval S, Daly AK, Pile KD, Calin A, Ebringer A, Weeks DE, Wordsworth BP. Polymorphisms of the CYP2D6 gene increase susceptibility to ankylosing spondylitis. Hum Mol Genet 2000; 9:1563-6. [PMID: 10861282 DOI: 10.1093/hmg/9.11.1563] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ankylosing spondylitis (AS) is a common and highly familial rheumatic disorder. The sibling recurrence risk ratio for the disease is 63 and heritability assessed in twins >90%. Although MHC genes, including HLA-B27, contribute only 20-50% of the genetic risk for the disease, no non-MHC gene has yet been convincingly demonstrated to influence either susceptibility to the disease or its phenotypic expression. Previous linkage and association studies have suggested the presence of a susceptibility gene for AS close to, or within, the cytochrome P450 2D6 gene (CYP2D6, debrisoquine hydroxylase) located at chromosome 22q13.1. We performed a linkage study of chromosome 22 in 200 families with AS affected sibling-pairs. Association of alleles of the CYP2D6 gene was examined by both case-control and within-family means. For case-control studies, 617 unrelated individuals with AS (361 probands from sibling-pair and parent-case trio families and 256 unrelated non-familial sporadic cases) and 402 healthy ethnically matched controls were employed. For within-family association studies, 361 families including 161 parent-case trios and 200 affected sibling-pair families were employed. Homozygosity for poor metabolizer alleles was found to be associated with AS. Heterozygosity for the most frequent poor metabolizer allele (CYP2D6*4) was not associated with increased susceptibility to AS. Significant within-family association of CYP2D6*4 alleles and AS was demonstrated. Weak linkage was also demonstrated between CYP2D6 and AS. We postulate that altered metabolism of a natural toxin or antigen by the CYP2D6 gene may increase susceptibility to AS.
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Affiliation(s)
- M A Brown
- Wellcome Trust Centre for Human Genetics, Headington, Oxon, UK.
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Abstract
AIMS Terodiline has concentration dependent QT prolonging effects and thus the potential for cardiotoxicity. Pharmacogenetic variation in terodiline metabolism could be responsible for cardiotoxicity. We sought to determine whether CYP2D6 (debrisoquine hydroxylase) or CYP2C19 (S-mephenytoin hydroxylase) status is a risk factor for terodiline cardiotoxicity. METHODS Using the UK Yellow Card scheme to identify patients, blood samples were obtained from eight patients who survived ventricular tachycardia or torsades de pointes suspected to be due to terodiline, for determination of CYP2D6 and CYP2C19 genotypes. Genotype prevalence was compared with that in published general population groups. RESULTS One patient was a CYP2D6 poor metaboliser (CYP2D6*4 homozygous) and a second was heterozygous for CYP2D6*4, a slightly lower frequency for these genotypes compared with the general population (P = 0.31). In the case of CYP2C19, one patient was a poor metaboliser and four were heterozygous for the variant CYP2C19*2 allele, compared with general population frequencies of 2% and 23%, respectively (P = 0.035). CONCLUSIONS These findings suggest that debrisoquine poor metaboliser status is not primarily responsible for terodiline cardiotoxicity. However, possession of the CYP2C19*2 allele appears to contribute to adverse cardiac reactions to terodiline. The present study demonstrates the feasibility of using spontaneous adverse drug reaction reporting schemes to determine the contribution of genotype for metabolizing enzymes to uncommon adverse drug reactions.
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Affiliation(s)
- G A Ford
- Department of Pharmacological Sciences, University of Newcastle upon Tyne, UK.
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London SJ, Smart J, Daly AK. Lung cancer risk in relation to genetic polymorphisms of microsomal epoxide hydrolase among African-Americans and Caucasians in Los Angeles County. Lung Cancer 2000; 28:147-55. [PMID: 10717332 DOI: 10.1016/s0169-5002(99)00130-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Microsomal epoxide hydrolase participates in the metabolism of benzo[a]pyrene, an important carcinogen in tobacco smoke. Two relatively common polymorphisms of the microsomal epoxide hydrolase gene that influence enzyme activity have been described. An association between genetic variation in microsomal epoxide hydrolase and lung cancer risk has been reported in one of two studies of Caucasians. We examined the relation between these two polymorphisms and lung cancer risk among 337 incident cases and 700 population controls of African-American and Caucasian ethnicity enrolled in a case-control study in Los Angeles County. African-Americans, homozygous for the exon 3 variant allele conferring reduced activity, were at decreased risk of lung cancer (odds ratio (OR)=0.08, 95% CI 0.01-0.62). When data from both the exon 3 and exon 4 polymorphisms were combined into indices of predicted microsomal epoxide hydrolase activity, a decreased risk was seen among African-American subjects with very low predicted activity OR=0.10 (95% CI 0.01-0.83). No comparable association was seen among Caucasians. Although the three published results for Caucasians are somewhat variable, the association among African-Americans in these data provides some support for the hypothesis that genetically reduced microsomal epoxide hydrolase activity may be protective against lung cancer.
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Affiliation(s)
- S J London
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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Abstract
BACKGROUND The factors determining why less than 10% of heavy drinkers develop advanced alcoholic liver disease (ALD) remain elusive, although genetic factors may be important. Interleukin 10 (IL-10) is an important cytokine with anti-inflammatory, anti-immune, and antifibrotic functions. Several polymorphisms have been identified in the IL-10 promoter and recent evidence suggests that some of these may have functional effects on IL-10 secretion. AIMS To test the hypothesis that IL-10 promoter region polymorphisms are associated with susceptibility to ALD. METHODS The allele frequencies for the two single base pair substitutions at positions -627 (C-->A) and -1117 (A-->G) in the IL-10 promoter were determined in 287 heavy drinkers with biopsy proved advanced ALD, 107 heavy drinkers with no evidence of liver disease or steatosis only on biopsy, and 227 local healthy volunteers. RESULTS At position -627, 50% of patients with advanced ALD had a least one A allele compared with 33% of controls (p<0.0001) and 34% of drinkers with no or mild disease (p=0.017). At position -1117, the slight excess of the A allele in drinkers with advanced disease was because of linkage disequilibrium between the A alleles at the two sites. CONCLUSIONS Among heavy drinkers, possession of the A allele at position -627 in the IL-10 promoter is associated with an increased risk of advanced liver disease. This is consistent with recent functional data that the -627*A allele is associated with low IL-10 expression which will favour inflammatory, immune mediated, and profibrotic mechanisms of alcohol related liver injury.
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Affiliation(s)
- J Grove
- Centre for Liver Research, University of Newcastle, Newcastle-upon-Tyne, UK
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31
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Abstract
BACKGROUND/AIM Primary biliary cirrhosis (PBC) is an autoimmune cholestatic liver disease thought to develop through a complex interaction of genetic and environmental factors. It is characterised by T-cell-mediated non-suppurative destructive cholangitis. We have studied the polymorphic cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene, which encodes a molecule that is a vital negative regulator of T-cell activation, as a candidate susceptibility locus for PBC. This gene on chromosome 2q33 (designated IDDM12) is associated with susceptibility to both type 1 diabetes and autoimmune thyroid disease. METHODS The CTLA-4 exon 1 polymorphism (A/G encoding for threonine or alanine, respectively) was genotyped via polymerase chain reaction in 200 Caucasoid PBC patients and 200 non-related geographically matched Caucasoid controls. RESULTS There was significant overrepresentation of the G/A and G/G genotypes in PBC patients compared to controls (G/A 53% vs 40%; G/G 18.5% vs 10.5%, Odds Ratio (OR)=2.45 [95% CI 1.6-3.7], p=0.00006, chi2=19.4). Likewise, there was a significant difference in allele frequencies (G encoding alanine at codon 17, PBC 0.45 vs controls 0.305: OR=1.9 [1.4-2.5], p<0.0002). This association remained significant (p=0.00027) when patients with autoimmune thyroid disease were excluded from the analysis. CONCLUSIONS The CTLA-4 exon 1 polymorphism is the first non-major histocompatibility complex gene to be identified as a susceptibility locus for PBC. Our data support the hypothesis that clinically distinct autoimmune disease may be controlled by a common set of susceptibility genes.
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Affiliation(s)
- K Agarwal
- Centre for Liver Research, University of Newcastle, Newcastle Upon Tyne, UK
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32
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Abstract
AIMS To establish whether gender or N-acetyltransferase 2 (NAT2) genotype influence the urinary 17 U+17X/137X ratio after dosing with caffeine. METHODS Ninety-two nonsmoking individuals underwent caffeine phenotyping. NAT2 genotype was determined by the polymerase chain reaction followed by a restriction digest (PCR-RFLP). RESULTS The median ratio for urinary 17 U+17X/137X was 6.7 (range 1.45-18. 65). 55% of subjects were slow acetylators. Gender did not affect the metabolic ratio or NAT2 genotype. Mean 17 U+17X/137X ratio differed between fast (6.75) and slow (8.69) acetylators (95% CI for the difference, 0.32-3.56). CONCLUSIONS The findings are further evidence that the 17 U+17X/137X urinary ratio is not a robust measure of CYP1A2 activity. A possible mechanism by which the ratio might be influenced by NAT2 genotype is suggested.
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Affiliation(s)
- M R Welfare
- Department of Pharmacological Sciences and; Department of Medicine, Medical School, University of Newcastle, Newcastle upon Tyne, UK.
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33
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Ingelman-Sundberg M, Daly AK, Oscarson M, Nebert DW. Human cytochrome P450 (CYP) genes: recommendations for the nomenclature of alleles. Pharmacogenetics 2000; 10:91-3. [PMID: 10739177 DOI: 10.1097/00008571-200002000-00012] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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34
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Abstract
The genotypic basis of interindividual variation in levels of induced CYP1A1 activity has been investigated by screening both the CYP1A1 gene and the Ah receptor gene (AhR) for both previously described and novel polymorphisms. A 103-fold level of interindividual variation in induced CYPlA1 activity [ethoxyresorufin O-deethylase (EROD)] was observed in lymphocytes from a group of 30 Caucasian volunteers. High levels of induced EROD activity did not correlate with the presence of CYP1A1*2 or CYP1A1*4 alleles or with the GSTM1 null genotype. Novel CYP1A1 alleles with the base substitutions C4151T, G-469A and C-459T respectively, were detected by screening the coding exons and approximately 1 kb of upstream sequence in 20 individuals by single-strand conformational polymorphism (SSCP) analysis but none of the three novel alleles appeared to be associated with high induced CYP1A1 activity in the study group. Screening of the 11 exons of the AhR gene by SSCP analysis confirmed the existence of the previously described G1721A polymorphism in a Caucasian population and a novel allele (G1768A which results in the amino acid substitution V5701) was also detected. The novel allele was very rare in Caucasians though more common in African-Americans. Individuals with at least one copy of the G1721A AhR variant allele showed a significantly higher level of induced CYP1A1 activity compared with individuals negative for the polymorphism (P = 0.0001). A similar finding was obtained for induced CYP1A1 protein levels determined by immunoblotting. Levels of induced CYP1A1 activity were also found to show a sex difference with women showing a significantly lower induced activity compared with men. We conclude that genotypes for the G1721A AhR polymorphism and gender appear to be determinants of levels of induced CYP1A1 activity and that interindividual variation in levels of induced CYP1A1 activity appears to be associated more with regulatory factors than polymorphism in the CYP1A1 gene.
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Affiliation(s)
- J Smart
- Department of Pharmacological Sciences, University of Newcastle upon Tyne, UK
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35
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Chen GF, Tang YM, Green B, Lin DX, Guengerich FP, Daly AK, Caporaso NE, Kadlubar FF. Low frequency of CYP2A6 gene polymorphism as revealed by a one-step polymerase chain reaction method. Pharmacogenetics 1999; 9:327-32. [PMID: 10471064 DOI: 10.1097/00008571-199906000-00007] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Human cytochrome P450 2A6 (CYP2A6) has been shown to metabolically activate carcinogens and mutagens. Genetic polymorphisms for CYP2A6 have been reported previously in different ethnic groups using a two-step polymerase chain reaction (PCR) method to identify CYP2A6*1, CYP2A6*2 and CYP2A6*3. Moreover, a new truncated allele has been recently identified in a Japanese population. We report here a one-step PCR amplification of the CYP2A6 gene from human genomic DNA and the detection of intact CYP2A6 alleles by restriction enzyme digestion. The diagnostic exon (exon 3) of the CYP2A6 gene was amplified from human genomic DNA with a primer pair. The forward primer is unique to the CYP2A6 gene, which eliminates previous problems in amplifying two highly homologous CYP2A genes, CYP2A7 and CYP2A13, in humans. The resulting PCR products (214 bp) were digested with XcmI or DdeI to detect the presence of CYP2A6*2 or CYP2A6*3 alleles, respectively. The allelic frequencies for CYP2A6*2 were 2.3% (n = 320) in the Caucasian and 0.7% (n = 71) in the Chinese populations, respectively. CYP2A6*3 allelic frequency in the Chinese population was 0.7%; while no CYP2A6*3 allele was detected in the Caucasian population. The allelic frequencies are relatively low and the reason for this discrepancy between different methods is discussed.
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Affiliation(s)
- G F Chen
- Division of Molecular Epidemiology, National Center for Toxicological Research, Jefferson, Arkansas 72079, USA
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36
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Welfare MR, Aitkin M, Bassendine MF, Daly AK. Detailed modelling of caffeine metabolism and examination of the CYP1A2 gene: lack of a polymorphism in CYP1A2 in Caucasians. Pharmacogenetics 1999; 9:367-75. [PMID: 10471069 DOI: 10.1097/00008571-199906000-00012] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The cytochrome P450 CYP1A2 is important in the metabolism of both drugs and procarcinogens such as heterocyclic amines. We aimed to clarify the existence of a phenotypic polymorphism and explore the molecular basis of such a polymorphism. Ninety-two non-smoking individuals underwent caffeine phenotyping. The distribution of the 1,7-dimethylxanthine + 1,7-dimethyluracil/caffeine (17U + 17X/137X) ratio and log-transformed data were determined. Probit plots were constructed and the distribution fitted using maximum likelihood method. The CYP1A2 gene, including upstream regulatory regions, was examined for sequence polymorphisms using the single-strand conformation polymorphism technique in 19 individuals and by complete DNA sequencing in two individuals from the extremes of the distribution. We found a similar range (1.45-18.65) and median (6.7) for the 17U + 17X/137X ratio to that found in previous studies of non-smoking Caucasians and no effect of sex. The 17U + 17X/137X ratio gave a normal distribution when log-transformed. Maximum likelihood analysis showed that the log-normal and bimodal distributions had similar deviances but the log-normal distribution was favoured because it has fewer parameters. There was no evidence for significant DNA sequence differences between fast and slow metabolizers, although some differences from published sequences including a silent polymorhpism in exon 7 which were unlikely to be of functional significance were found. We therefore conclude that CYP1A2 does not show functionally significant polymorphism but that the wide interindividual variation in activity may be due to environmental factors.
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Affiliation(s)
- M R Welfare
- Department of Pharmacological Sciences, Medical School, University of Newcastle, Newcastle upon Tyne, UK.
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37
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Nebert DW, Ingelman-Sundberg M, Daly AK. Genetic epidemiology of environmental toxicity and cancer susceptibility: human allelic polymorphisms in drug-metabolizing enzyme genes, their functional importance, and nomenclature issues. Drug Metab Rev 1999; 31:467-87. [PMID: 10335448 DOI: 10.1081/dmr-100101931] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Pharmacogenetics is the study of idiosyncratic drug responses that have an hereditary basis and usually reflect differences in drug-metabolizing enzymes (DMEs) and the receptors that control DME levels. The purpose of this review is to provide a brief overview of recent findings concerning more than a dozen clinically important polymorphisms and to emphasize the need to standardize the nomenclature of these alleles in each polymorphism, as quickly as possible. This nomenclature system should be consistent with the Human Gene Nomenclature Guidelines. Because DMEs have existed before divergence of prokaryotes and eukaryotes more than 2 billion years ago, it is clear that DME genes first must have evolved for critical life functions and that, more recently in animals, DME genes expanded to include the role of detoxification of dietary products, evolving plant metabolites, and, of course, pharmaceutical drugs. Many human DME polymorphisms are relevant to clinical problems in that they represent the basis of risk factors in the development of cancer, toxicity, and other diseases associated with drug, chemical, or dietary exposure. The study of the relationship among human genetic polymorphisms, cancer susceptibility, toxicity, and environmental exposure is a new and exciting area of research--which will undoubtedly have increasingly important implications for risk assessment and the prevention, early diagnosis, and intervention of clinical disease.
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Affiliation(s)
- D W Nebert
- Center for Environmental Genetics, University of Cincinnati Medical Center, Ohio 45267-0056, USA.
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38
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Welfare M, Monesola Adeokun A, Bassendine MF, Daly AK. Polymorphisms in GSTP1, GSTM1, and GSTT1 and susceptibility to colorectal cancer. Cancer Epidemiol Biomarkers Prev 1999; 8:289-92. [PMID: 10207630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Polymorphisms in glutathione S-transferase (GSTs) may predispose to colorectal cancer through deficient detoxification of environmental carcinogens, although previous results are conflicting. A study with 178 matched case-control pairs was conducted to determine the effect of the GSTT1 and GSTM1 null genotypes and polymorphisms in GSTP1 on colorectal cancer susceptibility. In a secondary analysis, we examined interactions between genotypes and with the N-acetyltransferase 2 (NAT2) genotype. Heterogeneity by age, sex, site, and stage of cancer was also examined. No effect of any genotype for GSTM1, GSTT1, or GSTP1 on colorectal cancer susceptibility was detected. Secondary end points showed that individuals with both the GSTT1 null and NAT2 slow genotypes combined appeared to be at increased risk of colorectal cancer (odds ratio = 2.33; 95% confidence interval, 1.1-5.0). We conclude that GST polymorphisms alone do not predispose to colorectal cancer in northeast England. We also observed possible effects of the GSTT1 null genotype on the age and stage at presentation, and these, together with the findings of an apparent interaction with NAT2 genotypes, need to be confirmed in further studies.
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Affiliation(s)
- M Welfare
- Department of Pharmacological Sciences, University of Newcastle upon Tyne, England.
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39
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40
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Yule SM, Walker D, Cole M, McSorley L, Cholerton S, Daly AK, Pearson AD, Boddy AV. The effect of fluconazole on cyclophosphamide metabolism in children. Drug Metab Dispos 1999; 27:417-21. [PMID: 10064575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Fluconazole is increasingly used in children receiving chemotherapy. Many of these patients are being treated with cyclophosphamide, which must undergo hepatic metabolism to produce active alkylating species. As a consequence of the cytochrome P-450 inhibitory properties of fluconazole, a potential interaction exists between these two agents that could influence the therapeutic effect of cyclophosphamide. To investigate this interaction, a retrospective case series of patients was chosen from a population of children with a previously established profile of cyclophosphamide metabolism. Twenty-two children who were not receiving other therapy known to influence drug metabolism were selected and analyzed in terms of fluconazole treatment; of these, nine were receiving fluconazole and thirteen were identified as controls. Study design was not randomized. The plasma clearance of cyclophosphamide was lower in patients receiving fluconazole [mean(SD) 2.4(0.71) versus 4.2(1.2) l/h/m2, p =.001]. In vitro studies were performed to characterize the interaction between fluconazole and cyclophosphamide in six human liver microsomes. The concentration of fluconazole required to reduce the production of 4-hydroxycyclophosphamide to 50% of control values (IC50) varied between 9 and 80 microM (median 38 microM). Further studies of the effect of fluconazole on 4-hydroxycyclophosphamide production in vivo are warranted to determine whether this interaction reduces the therapeutic effect of cyclophosphamide in clinical practice.
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Affiliation(s)
- S M Yule
- Department of Hematology, Yorkhill NHS Trust, Glasgow, United Kingdom
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41
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Abstract
BACKGROUND The cytochrome P450 CYP2C9 is responsible for the metabolism of S-warfarin. Two known allelic variants CYP2C9*2 and CYP2C9*3 differ from the wild type CYP2C9*1 by a single aminoacid substitution in each case. The allelic variants are associated with impaired hydroxylation of S-warfarin in in-vitro expression systems. We have studied the effect of CYP2C9 polymorphism on the in-vivo warfarin dose requirement. METHODS Patients with a daily warfarin dose requirement of 1.5 mg or less (low-dose group, n=36), randomly selected patients with a wide range of dose requirements from an anticoagulant clinic in north-east England (clinic control group, n=52), and 100 healthy controls from the community in the same region were studied. Genotyping for the CYP2C9*2 and CYP2C9*3 alleles was done by PCR analysis. Case notes were reviewed to assess the difficulties encountered during the induction of warfarin therapy and bleeding complications in the low-dose and clinic control groups. FINDINGS The odds ratio for individuals with a low warfarin dose requirement having one or more CYP2C9 variant alleles compared with the normal population was 6.21 (95% CI 2.48-15.6). Patients in the low-dose group were more likely to have difficulties at the time of induction of warfarin therapy (5.97 [2.26-15.82]) and have increased risk of major bleeding complications (rate ratio 3.68 [1.43-9.50]) when compared with randomly selected clinic controls. INTERPRETATION We have shown that there is a strong association between CYP2C9 variant alleles and low warfarin dose requirement. CYP2C9 genotyping may identify a subgroup of patients who have difficulty at induction of warfarin therapy and are potentially at a higher risk of bleeding complications.
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Affiliation(s)
- G P Aithal
- Department of Medicine, University of Newcastle upon Tyne Medical School, UK
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42
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Atkinson A, Singleton AB, Steward A, Ince PG, Perry RH, McKeith IG, Fairbairn AF, Edwardson JA, Daly AK, Morris CM. CYP2D6 is associated with Parkinson's disease but not with dementia with Lewy Bodies or Alzheimer's disease. Pharmacogenetics 1999; 9:31-5. [PMID: 10208640 DOI: 10.1097/00008571-199902000-00005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The similarities between the clinical and pathological findings of dementia with Lewy Bodies (DLB) with Alzheimer's disease and Parkinson's disease are complex, and their significance for pathogenesis is unresolved. It is likely that DLB shares common disease determinants with both Alzheimer's disease and Parkinson's disease. Clinically DLB shows the presence of dementia similar, though not identical, to that found in Alzheimer's disease. A parkinsonian movement disorder is present in a proportion of DLB cases. Pathologically DLB shows senile plaques, as with Alzheimer's disease, and also substantia nigra neurone loss and Lewy bodies, as with Parkinson's disease. At a genetic level, DLB shows an elevated Apolipoprotein E epsilon4 frequency as described in Alzheimer's disease, but this is absent in Parkinson's disease. An elevated frequency of the CYP2D6*4 allele has been found in Parkinson's disease and we have therefore genotyped a large series of clinically and neuropathologically confirmed cases of DLB, Alzheimer's disease, Parkinson's disease and age-matched control individuals for the CYP2D6*4 allele. Whilst an elevated frequency of the CYP2D6*4 allele was found in Parkinson's disease, no such elevations were found in DLB or Alzheimer's disease. Stratification of the CYP2D6*4 allele with respect to the Apolipoprotein E epsilon4 also did not show any significant associations with the CYP2D6*4 allele. The CYP2D6*4 allele is not a major genetic determinant of DLB and the results place DLB with Alzheimer's disease rather than Parkinson's disease on a genetic level.
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Affiliation(s)
- A Atkinson
- Medical Research Council Neurochemical Pathology Unit, Institute for the Health of the Elderly, Newcastle General Hospital, Newcastle upon Tyne, UK
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43
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Jones DE, Watt FE, Grove J, Newton JL, Daly AK, Gregory WL, Day CP, James OF, Bassendine MF. Tumour necrosis factor-alpha promoter polymorphisms in primary biliary cirrhosis. J Hepatol 1999; 30:232-6. [PMID: 10068101 DOI: 10.1016/s0168-8278(99)80067-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND/AIMS The incidence of primary biliary cirrhosis (PBC) is increased in the close relatives of patients, suggesting that genetic factors play a role in disease susceptibility. Decreased in vitro production of tumour necrosis factor (TNF)-alpha has been reported in PBC patients, suggesting a potential aetiological role for this cytokine. The aim of this study was to examine two biallelic polymorphisms in the promoter region of the TNF-alpha gene, which may play a role in the control of TNF-alpha secretion, as candidate susceptibility loci in PBC. METHODS The polymorphisms at positions -238 and -308 in the TNF-alpha promoter region were analysed by polymerase chain reaction in 168 unrelated PBC patients and 145 local unrelated, geographically matched normal individuals. All PBC subjects were also genotyped for HLA DR8, a previously identified susceptibility locus in PBC. RESULTS The -308 TNF1/TNF1 genotype was seen in a similar proportion of PBC patients (66%) and controls (60%). However, this genotype was found significantly more frequently in the 95 PBC patients with more advanced disease (histological stage III/IV) (77%) than in either controls (p<0.01, OR = 2.2 [1.2-4.0]) or the PBC patients with earlier disease (38/73 (52%), p = 0.001 OR 3.1 [1.6-5.9]). Linkage between TNF -308 and HLA DR8 was not seen. No association was found between PBC and the biallelic -238 TNF-alpha polymorphism, either in the whole PBC population or the histological Stage III/IV subgroup. CONCLUSIONS Our study provides no evidence for involvement of the TNF-alpha -308 or -238 promoter polymorphisms in genetic predisposition to PBC. However, the significantly increased frequency of the -308 TNF1/TNF1 genotype seen in 95 patients with more advanced disease raises the possibility that this allele may be linked to disease progression rather than susceptibility. The finding of different allele frequencies in PBC patients in different disease subgroups emphasises the importance of clinical phenotype/casemix in the design of disease association studies.
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Affiliation(s)
- D E Jones
- Centre for Liver Research, University of Newcastle, Newcastle upon Tyne, UK
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44
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Abstract
The cytochrome P450 superfamily is known to exhibit a high degree of genetic polymorphism and polymorphisms associated with absent or low enzyme activity in CYP2D6, CYP2C19 and CYP2C9 are particularly well studied. However, despite early reports of strong disease associations for particular CYP2D6 phenotypes, these have not been confirmed in recent, more detailed studies and it now appears that analysis of CYP2D6, CYP2C19 and CYP2C9 genotype is of most value in predicting metabolism of specific drugs. Polymorphisms in other cytochrome P450 genes are less well studied and appear not to be associated with complete absence of enzyme activity. We have recently carried out studies of polymorphism in both CYP1A1 and CYP2E1. The molecular basis of the apparent CYP1A1 'high inducibility' polymorphism was investigated by studying CYP1A1 and Ah receptor polymorphisms in a group of phenotyped individuals who were genotyped both for known and novel CYP1A1 and Ah receptor polymorphisms. Three novel polymorphisms in CYP1A1 (C(-459)T, G(-469)A and C(4151)T) and one in the Ah receptor (G(1768)A; V(570)I) were detected by single strand conformational polymorphism analysis and DNA sequencing. Among both novel and previously known polymorphisms, only the Ah receptor G(1721)A polymorphism, which has an allele frequency of 0.12 in Caucasians and was detected previously in a Japanese population, was significantly associated with high induced CYP1A1 activity. In the case of CYP2E1, we have detected three polymorphisms in the promoter region (A(-316)G, T(-297)A and G(-35)T) and one in the coding sequence (G(4804)A; V(179)I) by screening Caucasian DNA samples. The significance of these alleles has been investigated but only G(-35)T combined with T(-297)A, which has an allele frequency of 0.05, appears to be of functional significance, with an apparent 1.8-fold increase in levels of transcriptional activity compared with the wild-type.
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Affiliation(s)
- A K Daly
- Department of Pharmacological Sciences, Medical School, University of Newcastle upon Tyne, UK.
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45
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Fairbrother KS, Grove J, de Waziers I, Steimel DT, Day CP, Crespi CL, Daly AK. Detection and characterization of novel polymorphisms in the CYP2E1 gene. Pharmacogenetics 1998; 8:543-52. [PMID: 9918138 DOI: 10.1097/00008571-199812000-00011] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
To investigate whether interindividual variation in CYP2E1 levels can be explained by genetic polymorphism, we analysed DNA samples from 40 healthy individuals by single-strand conformational polymorphism analysis for polymorphisms in the CYP2E1 coding sequence and promoter region. DNA sequencing of samples showing mobility shifts on single-strand conformational polymorphism detected polymorphisms at positions -316 (A to G), -297 (T to A), -35 (G to T), 1107 (G to C; intron 1), 4804 (G to A Val179Ile; exon 4) and 10157 (C to T; exon 8). All individuals positive for either A(-316)G, G(-35)T, G(4804)A or the previously described RsaI polymorphism at -1019 were also positive for T(-297)A, which had the highest allele frequency of the observed polymorphisms (0.20). A(-316)G, G(-35)T and G(4804)A were detected at allele frequencies of 0.022, 0.052 and 0.013, respectively. The functional significance of the upstream polymorphisms was examined by preparing constructs of positions -549 to +3 of CYP2E1 containing the observed combinations of the polymorphisms fused to luciferase reporter genes and transfecting HepG2 cells. For the G(-35)T/T(-297)A construct, a 1.8-fold increase in luciferase activity compared with the wild-type sequence (P = 0.06) and 2.5-fold compared with T(-297)A only (P = 0.025) was observed. No significant difference in activity was observed between the other constructs. The significance of the predicted Val179Ile base change from G(4804)A was determined by expression of the wild-type and mutated full length cDNAs in lymphoblastoid cells. No significant difference in kinetic constants for chlorzoxazone hydroxylation between mutant and wild-type was observed. In summary, this study demonstrated six novel CYP2E1 polymorphisms, including three upstream of the promoter, but with the possible exception of G(-35)T, none appeared to be of functional significance.
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Affiliation(s)
- K S Fairbrother
- Department of Pharmacological Sciences, University of Newcastle upon Tyne, Medical School, UK
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46
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Leathart JB, London SJ, Steward A, Adams JD, Idle JR, Daly AK. CYP2D6 phenotype-genotype relationships in African-Americans and Caucasians in Los Angeles. Pharmacogenetics 1998; 8:529-41. [PMID: 9918137 DOI: 10.1097/00008571-199812000-00010] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
CYP2D6 genotyping (CYP2D6*3, CYP2D6*4, CYP2D6*5, CYP2D6*13, CYP2D6*16 alleles and gene duplications) was previously performed on 1053 Caucasian and African-American lung cancer cases and control individuals and no significant difference in allele frequencies between cases and control individuals detected. We have carried out additional genotyping (CYP2D6*6, CYP2D6*7, CYP2D6*8, CYP2D6*9, CYP2D6*10, CYP2D6*17 alleles) and debrisoquine phenotyping on subgroups from this study to assess phenotype-genotype relationships. African-Americans showed significant differences from Caucasians with respect to frequency of defective CYP2D6 alleles, particularly CYP2D6*4 and CYP2D6*5. The CYP2D6*17 allele occurred at a frequency of 0.26 among 87 African-Americans and appeared to explain higher average metabolic ratios among African-Americans compared with Caucasians. CYP2D6*6, CYP2D6*8, CYP2D6*9 and CYP2D6*10 were rare in both ethnic groups but explained approximately 40% of higher than expected metabolic ratios among extensive metabolizers. Among individuals phenotyped with debrisoquine, 32 out of 359 were in the poor metabolizer range with 24 of these (75%) also showing two defective CYP2D6 alleles. Additional single strand conformational polymorphism analysis screening of samples showing large phenotype-genotype discrepancies resulted in the detection of three novel polymorphisms. If subjects taking potentially interfering drugs were excluded, this additional screening enabled the positive identification of 88% of phenotypic poor metabolizers by genotyping. This sensitivity was comparable with that of phenotyping, which identified 90% of those with two defective alleles as poor metabolizers.
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Affiliation(s)
- J B Leathart
- Department of Pharmacological Sciences, University of Newcastle upon Tyne, Medical School, UK
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47
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Abstract
BACKGROUND Iron overload is common in the livers of alcoholics and may play a role in disease pathogenesis. An MHC like gene, HFE, has recently been identified that is mutated in most patients with hereditary haemochromatosis (C282Y in 90% and H63D in 45% of the remainder). AIM To examine the hypothesis that these mutations determine hepatic iron status in alcoholics and play a role in pre-disposition to advanced alcoholic liver disease. METHODS The HFE gene was genotyped in 257 patients with alcoholic liver disease and 117 locally matched healthy volunteers. In addition, iron staining was scored (0-4) on biopsy specimens from fibrotic/cirrhotic patients with and without HFE mutations matched for age and sex. RESULTS Some 15.7% of fibrotic/cirrhotic patients were C282Y heterozygotes compared with 13.7% of controls (p = 0.77). One control and three patients were C282Y homozygotes. Of chromosomes without the C282Y mutation, 68/442 (15.4%) of patients' chromosomes carried the H63D mutation compared with 36/216 (16.6%) of control chromosomes (p = 0.91). Significant (> grade 1) hepatocyte iron staining was seen in 6/23 C282Y heterozygotes and 4/26 H63D heterozygotes compared with 4/23 controls. CONCLUSIONS Possession of a single copy of either of the two HFE mutations influences neither liver iron content nor the risk of fibrotic disease in alcoholics.
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Affiliation(s)
- J Grove
- Centre for Liver Research, University of Newcastle upon Tyne, UK
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48
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Grove J, Brown AS, Daly AK, Bassendine MF, James OF, Day CP. The RsaI polymorphism of CYP2E1 and susceptibility to alcoholic liver disease in Caucasians: effect on age of presentation and dependence on alcohol dehydrogenase genotype. Pharmacogenetics 1998; 8:335-42. [PMID: 9731720 DOI: 10.1097/00008571-199808000-00007] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Twin studies in Caucasians suggest that susceptibility to alcoholic liver disease is, in part, genetically determined. Because most of the deleterious effects of alcohol are caused by its metabolism, attention has focused upon genes encoding ethanol metabolizing enzymes. Caucasians are polymorphic at only two of these gene loci--cytochrome P450 2E1 (CYP2E1) and alcohol dehydrogenase 3 (ADH3). We examined the frequency of the RsaI polymorphism of CYP2E1 and ADH3 genotype in 264 patients with alcoholic liver disease and 121 local control individuals. There was a non-significant excess of the rare c2 CYP2E1 allele in patients with advanced liver disease compared with control individuals/patients with steatosis only (0.029 versus 0.017/0.00). However, patients with the c2 allele presented at a younger age compared with those with the wild type c1 allele only (42.3 +/- 1.6 years versus 49.0 +/- 0.6 years; P = 0.001) with at least as advanced histology (93% cirrhotic versus 74%). Male patients had a higher frequency of the ADH3*2/*2 genotype (which encodes the less active gamma2 subunit) than control individuals [odds ratio (OR) 2.04 (1.11-3.76)], however, ADH3 genotype did not differ with histological stage or with age of presentation. Patients with advanced disease possessing the c2 allele had a significantly higher frequency of the ADH3*2/*2 genotype compared with c1 homozygotes [OR 3.71 (1.24-11.09)]. This study demonstrates that, although rare in Caucasians, possession of the mutant c2 allele of CYP2E1 increases the risk of alcoholic liver disease at a given level of cumulative alcohol consumption. This risk appears to be particularly manifest in individuals carrying the ADH3*2 allele, presumably reflecting increased metabolism of ethanol by CYP2E1. In the absence of the c2 allele, ADH3 genotype does not influence the risk of advanced alcoholic liver disease but, in males at least, may influence the risk of alcoholism.
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Affiliation(s)
- J Grove
- Department of Medicine, University of Newcastle upon Tyne, UK
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49
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Smith BC, Gorve J, Guzail MA, Day CP, Daly AK, Burt AD, Bassendine MF. Heterozygosity for hereditary hemochromatosis is associated with more fibrosis in chronic hepatitis C. Hepatology 1998; 27:1695-9. [PMID: 9620344 DOI: 10.1002/hep.510270631] [Citation(s) in RCA: 153] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatic iron has been associated with more aggressive liver disease in chronic viral hepatitis. We evaluated whether the recently described C282Y mutation of the hemochromatosis gene, designated HFE (responsible for at least 83% of hereditary hemochromatosis), was associated with more advanced liver disease in chronic hepatitis C. One hundred thirty-seven patients with biopsy-proven chronic hepatitis C were studied and liver biopsies scored for necroinflammation (grade 0-18) and fibrosis (stage 0-6). Genomic DNA was amplified by polymerase chain reaction and the C282Y mutation identified by restriction with RsaI and electrophoretic separation of restriction fragments. Ten (7.3%) patients had the C282Y mutation. No C282Y homozygous patients were identified. Age, sex distribution, and estimated weekly alcohol consumption were not significantly different between those with and without the mutation. Serum ferritin was higher in the heterozygotes (mean, 339 microg/L) compared with homozygous wild types (153 microg/L; P = .0005). In the majority of patients, liver iron was graded 0 out of 4, but hepatocyte iron staining was more commonly present in heterozygotes compared with homozygous normals (30% compared with 4% [P = .02]). Liver disease was more advanced in those with the mutant allele (mean fibrosis stage: 3.6, compared with wild type: 1.5 [P = .01]). Cirrhosis was found more often in those with the mutation (40%) compared with those without (8.7%) (P = .01; odds ratio: 7.6 [1.9-31.2]). There was no significant difference in inflammation scores between heterozygotes and wild type (mean, 5.4 compared with 4.1). Hepatitis C virus (HCV)-RNA titers were measured by branched DNA assay (HCV RNA 2.0-Chiron), and there was no difference between heterozygous and homozygous normal patients. Thus, despite relatively minor increases in iron stores, individuals who are heterozygous for hemochromatosis appear to develop more fibrosis in chronic hepatitis C. Venesection may be useful therapy in this subgroup.
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Affiliation(s)
- B C Smith
- Centre for Liver Research, University of Newcastle upon Tyne, England, UK
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Zappala F, Grove J, Watt FE, Daly AK, Day CP, Bassendine MF, Jones DE. No evidence for involvement of the interleukin-10 -592 promoter polymorphism in genetic susceptibility to primary biliary cirrhosis. J Hepatol 1998; 28:820-3. [PMID: 9625317 DOI: 10.1016/s0168-8278(98)80232-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND/AIMS Primary biliary cirrhosis is a chronic cholestatic liver disease with an autoimmune aetiology. Family studies, which have shown a significantly increased incidence of primary biliary cirrhosis in the close relatives of patients, suggest that genetic factors play a significant role in determining disease susceptibility. Several studies have previously identified loci which appear to play a role in determining this susceptibility, including the MHC class II allele HLA DR8, and the class III encoded C4A null allele (C4AQ0). Here, we have studied another candidate susceptibility locus in primary biliary cirrhosis, an apparently functional biallelic polymorphism at position -592 in the promoter region of the gene encoding the immuno-modulatory cytokine interleukin-10. Interleukin-10 plays an important role in the functional control, in vivo, of autoreactive Th-1 type CD4+ T-cells, with experimental manipulation of interleukin-10 leading to significant modulation of disease development in animal models of autoimmunity. METHODS Interleukin-10 -592 genotypes were studied by polymerase chain reaction in 171 well-characterised, histologically-staged, primary biliary cirrhosis patients and 141 locally matched controls. RESULTS Of 171 primary biliary cirrhosis patients, 99 were homozygous for the commoner allele (C/C), 68/171 (40%) were heterozygotes (A/C), whilst 4/171 (2%) were homozygous for the rarer allele (A/A). These genotype frequencies were not significantly different from those seen in controls (p=0.49, odds ratio 1.2 [0.8-1.91). CONCLUSIONS These findings, in the first study of IL-10 as a candidate locus in a human autoimmune disease, suggest that IL-10 -592 is not a susceptibility locus in primary biliary cirrhosis.
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Affiliation(s)
- F Zappala
- Center for Liver Research, University of Newcastle, Newcastle-upon-Tyne, UK
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