Yueh, M.F., Kawahara, M. and Raucy, J.
Notes: A CYP3A4 response element consisting of proximal and distal enhancer sequences with the CYP3A4 promoter was cloned into a pGL3 vector and used in transfection studies with HepG2 cells. The effects of either or both enhancer motifs on luciferase expression were studied in relation to various xenochemical treatments. The researchers also used the P450-Glo™ CYP3A4 Assay to analyze increases in CYP3A4 activities in a stably transfected cell line (DPX-2) and on primary hepatocytes. For these assays, the researchers incubated cells in 96-well or 24-well plates with or without CYP3A4 inhibitors and the P450-Glo™ CYP3A4 substrate. Following a 3 hour incubation, the P450-Glo™ Detection Reagent was added and the luminescence was recorded. In these studies cells were also pretreated with various chemicals including 10µM rifampicin, 1000µM phenobarbital, 100µM dexamethasone, 50µg/ml kava, 50µM methoxychlor, 50µM troglitazone, 100µM omeprazole, 100µM 2-acetylaminofluorene, and 25 µM chrysin. (3221)