Fig. 9.

CINPA1 disrupts CITCO-activated CAR binding to DNA response elements at the CYP2B6 and CYP3A4 gene promoter regions. (A–C). Freshly plated human hepatocytes (HPH) were treated for 45 minute with DMSO, 0.1 µM CITCO, 1 µM CINPA1, or 0.1 µM CITCO + 1 µM CINPA1. Protein complexes were cross-linked, and chromatin was immunoprecipitated by using anti-CAR antibody, anti–RNA polymerase II (RPol) antibody, or control IgG. CAR or RPol occupancy at the CYP2B6-dNR3 region, CYP3A4-XREM region, and a CAR-free intergenic region (ChIP negative control) was determined by performing quantitative real-time PCR assays. Fold-enrichment was normalized to IgG control. Data represent the mean ± S.D. of three PCRs and are representative of other experiments. One-way analysis of variance with Fisher’s least significant difference test was used to compare multiple treatment groups. **P < 0.01; ***P < 0.001 compared with DMSO samples. ^##P < 0.01; ^###P < 0.001 compared with CITCO samples.