High volume bioassays to assess CYP3A4-mediated drug interactions: induction and inhibition in a single cell line.
Article Details
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Yueh MF, Kawahara M, Raucy J
High volume bioassays to assess CYP3A4-mediated drug interactions: induction and inhibition in a single cell line.
Drug Metab Dispos. 2005 Jan;33(1):38-48. Epub 2004 Oct 1.
- PubMed ID
- 15466163 [ View in PubMed]
- Abstract
Exposure to certain xenochemicals can alter the catalytic activity of the major drug-metabolizing enzyme, CYP3A4, either by enhancing expression of this cytochrome P450 or inhibiting its activity. Such alterations can result in adverse consequences stemming from drug-drug interactions. A simplified and reliable tool for detecting the ability of candidate drugs to alter CYP3A4 levels or inhibit catalytic activity was developed by stable integration of human pregnane X receptor and a luciferase vector harboring the CYP3A4 enhancers. Treatment of stable transformants, namely DPX-2, with various concentrations of inducers including rifampicin, mifepristone, troglitazone, methoxychlor, and kava produced dose-dependent increases in luciferase expression (between 2- and 40-fold above dimethyl sulfoxide-treated cells). Northern blot analyses of CYP3A4 mRNA in DPX-2 cells exhibited a good correlation to results generated with the reporter gene assay (r(2) = 0.5, p < 0.01). Induction of CYP3A4 protein was examined by measuring catalytic activity with the CYP3A4 substrate, luciferin 6' benzyl ether (luciferin BE). Metabolism of luciferin BE by DPX-2 cells was enhanced 5.2-fold above dimethyl sulfoxide-treated cells by treatment with rifampicin. Constitutive androstane receptor-mediated regulation of CYP3A4 protein was addressed by measuring catalytic activity in a separate cell line over-expressing this receptor. Phenobarbital and dexamethasone produced 1.5- and 2.0-fold increases, respectively, above control in luciferin BE metabolism. To determine the utility of DPX-2 cells for identifying inhibitors of CYP3A4 catabolism, luciferin BE activity was measured in the presence of various concentrations of ketoconazole, erythromycin, or kava. These agents exhibited dose-dependent decreases in CYP3A4 activity with IC(50) values of 0.3 microM for ketoconazole, 108 microM for erythromycin, and 15.5 microg/ml for kava. Collectively, DPX-2 cells were used to identify xenobiotics that induce or inhibit CYP3A4 in a high throughput manner, demonstrating their applicability to early-stage drug development.
DrugBank Data that Cites this Article
- Drug Enzymes
Drug Enzyme Kind Organism Pharmacological Action Actions Mifepristone Cytochrome P450 3A4 Protein Humans UnknownSubstrateInhibitorInducerDetails - Pharmaco-transcriptomics
Drug Drug Groups Gene Gene ID Change Interaction Chromosome Clotrimazole Approved Vet Approved CYP3A4 1576 upregulated Clotrimazole results in increased expression of CYP3A4 mRNA 7q22.1 Dexamethasone Approved Investigational Vet Approved CYP3A4 1576 upregulated Dexamethasone results in increased expression of CYP3A4 mRNA 7q22.1 Mevastatin Experimental CYP3A4 1576 upregulated mevastatin results in increased expression of CYP3A4 mRNA 7q22.1 Mifepristone Approved Investigational CYP3A4 1576 upregulated Mifepristone results in increased expression of CYP3A4 mRNA 7q22.1 Omeprazole Approved Investigational Vet Approved CYP3A4 1576 upregulated Omeprazole results in increased expression of CYP3A4 mRNA 7q22.1 Phenobarbital Approved Investigational CYP3A4 1576 upregulated Phenobarbital results in increased expression of CYP3A4 mRNA 7q22.1 Phenytoin Approved Vet Approved CYP3A4 1576 upregulated Phenytoin results in increased expression of CYP3A4 mRNA 7q22.1 Rifampicin Approved CYP3A4 1576 upregulated Rifampin results in increased expression of CYP3A4 mRNA 7q22.1 Troglitazone Approved Investigational Withdrawn CYP3A4 1576 upregulated troglitazone results in increased expression of CYP3A4 mRNA 7q22.1