H4-II-E-C3 cells were seeded in 48-well plates at a density of 1.2 × 105. After an overnight incubation, the cells were transiently transfected by GenJet with a mixture containing a reporter (50 ng) along with 5 ng of the tk-Renilla luciferase plasmid. After incubation at 37°C for 24 h (serum-free medium), the transfected cells were treated with dexamethasone (50 nM), esfenvalerate (10 μM), or both for 48 h. Alternatively, esfenvalerate was used at various concentrations (0–10 μM). Luciferase activities were determined with a Dual-Luciferase Reporter Assay System and the reporter activity was normalized based on the Renilla luminescence signal. (A) Activation of the CYP3A23-Luc reporter (basic + upstream regulatory sequence), (B) Activation of the CYP3A23-198Luc reporter (basic) or its mutant the CYP3A23-198mLuc reporter (basic with disrupted DexRE1), and (C) Activation of the CYP3A4-DP-Luc reporter. Data presented in this figure were assembled from three independent experiments and each experiment was performed in triplicate. *Statistical significance (Fig, 6B, Right of Figs. 6A and 6C) (p < 0.05) and bars with a different letter indicate statistically significant differences Figs. 6A and 6C (Right).