Fig. 1.

RORα regulates the basal expression of CYP2B6 in the liver cells. (A) The expression of CYP2B6 mRNAs was suppressed when RORα expression was attenuated by treatment with siRNAs targeting RORα (n = 5). (B and C) RORα activated CYP2B6 reporter gene. Cell-based reporter assays were performed in COS-1 cells transiently expressing RORα and a luciferase reporter gene harboring −1.8 kb CYP2B6 promoter (n = 3). RORα activated this −1.8 kb CYP2B6 reporter but was unable to do so when the RORα response element was deleted as shown in (C). Luc on vertical axes stands for luciferase. The asterisk (*) between the groups represents statistically significant difference (**P < 0.01; ***P < 0.001). Mean and S.D. are shown for each group of treatment.