repost- Oct 2003
249. IN VITRO INDUCTION OF CYTOCHROME P450S AND DRUG TRANSPORTERS USING THE FA2N-4 IMMORTALIZED HUMAN HEPATOCYTE LINE
Amber L. Morris, Emron Awwal, and Karl Bruce Frank*
Non-Clinical Drug Safety, Hoffmann-La Roche Inc., 340 Kingsland St., Nutley, NJ 07110
Previously, the Fa2N-4 immortalized human hepatocyte line (MultiCell Technologies, Warwick, RI) was reported to be inducible for CYP2C9, CYP3A4 and several other functions involved in drug metabolism (Mills et al., 2002. Drug Metabolism Reviews 34, suppl. 1). We extended these investigations in the following ways: 1) isoform-specific TaqMan primers and probes were used to confirm the identity of the induced P450s; 2) LC-MS/MS methods and a cocktail containing the probe substrates midazolam and diclofenac were developed to permit simultaneous measurement of the induction of CYP2C9 and CYP3A4/5 enzyme activities; 3) this assay was miniaturized and demonstrated to work in the 96-well cell culture format. These developments facilitated robotic sample processing and higher throughput compared to the original 6-well assay. With a panel of three inducers (rifampicin, phenobarbital and omeprazole) the fold induction of CYP1A2, CYP2C9, CYP3A4, MDR-1 and MRP2 was quantitatively and qualitatively similar to induction obtained with cultures of fresh and cryopreserved hepatocytes isolated from several human donors. In summary, Fa2N-4 cells are a convenient and viable alternative to primary human hepatocytes for evaluating the potential of investigational compounds to induce Drug Metabolizing Enzymes and Drug Transporters.
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Roche presented the above paper at the 12th ISSX conference in Oct. 2003.
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