1. New insights into the regulation of CYP2C9 gene expression: the role of the transcription factor GATA-4
- Author
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Ellie Landman, Souren Mkrtchian, Yvonne Hofmann, Isa Cavaco, Jana Nekvindová, Magnus Ingelman-Sundberg, Rasmus Steen Pedersen, Jessica Mwinyi, University of Zurich, and Mwinyi, J
- Subjects
Chromatin Immunoprecipitation ,3003 Pharmaceutical Science ,Activation ,Pharmaceutical Science ,610 Medicine & health ,Electrophoretic Mobility Shift Assay ,Biology ,Transfection ,Gene Expression Regulation, Enzymologic ,Cytochrome P4502C9 ,Mice ,Genes, Reporter ,Cell Line, Tumor ,GATA6 Transcription Factor ,Gene expression ,Transcriptional regulation ,Animals ,Humans ,Cyp19 Expression ,Electrophoretic mobility shift assay ,Binding site ,Promoter Regions, Genetic ,Transcription factor ,Cytochrome P-450 CYP2C9 ,Pharmacology ,Binding Sites ,GATA2 ,Heart ,Hep G2 Cells ,Molecular biology ,Rat Granulosa-Cells ,GATA4 Transcription Factor ,DNA-Binding Proteins ,GATA2 Transcription Factor ,Nuclear Factor-4-Alpha ,Transporters ,3004 Pharmacology ,Hepatocyte-Nuclear-Factor-4-Alpha ,Metabolism ,10199 Clinic for Clinical Pharmacology and Toxicology ,embryonic structures ,Mutation ,Hepatocytes ,GATA transcription factor ,Aryl Hydrocarbon Hydroxylases ,Polymorphisms ,Chromatin immunoprecipitation ,Transcription Factors - Abstract
CYP2C9 is an important drug-metabolizing enzyme that metabolizes, e. g., warfarin, antidiabetics, and antiphlogistics. However, the endogenous regulation of this enzyme is largely unknown. In this study, we examined the role of GATA transcription factors in the gene expression of CYP2C9. We investigated four putative GATA binding sites within the first 200 base pairs of CYP2C9 promoter at the positions I: -173/-170, II: -167/-164, III: -118/ -115, and IV: -106/-103. Luciferase activity driven by a wildtype CYP2C9 promoter construct was strongly up-regulated in Huh-7 cells upon cotransfection with expression plasmids for GATA-2 and GATA-4, whereas mutations introduced into GATA binding site III or I and II reduced this induction to a significant extent. Electrophoretic mobility shift assays revealed specific binding of GATA-4 and GATA-6 to the oligonucleotides containing GATA binding sites I and II. Furthermore, the association of GATA-4 with CYP2C9 promoter was confirmed by chromatin immunoprecipitation assays in HepG2 cells. Taken together, these data strongly suggest an involvement of liver-specific transcription factor GATA-4 in the transcriptional regulation of CYP2C9. Swedish Research Council; Stockholm County Council; Danish Agency of Science, Technology and Innovation; Lundbeck Foundation; Portuguese Foundation for Science and Technology [SFRH/BPD/34152/2006 IBB/CBME]
- Published
- 2009