Figure 4.

Activation of CXR by different drugs. (A) CV-1 cells were cotransfected with an expression plasmid for CXR together with a CAT reporter gene plasmid containing the CYP2H1 264-bp PBRU. Cells were then treated with either vehicle or drugs for 24 h. Cell extracts were analyzed for CAT expression normalized against β-galactosidase levels. (B) Activation pattern of the CYP2H1 264-bp PBRU. LMH cells were transfected with the 264-bp PBRU in a CAT reporter gene plasmid and induced for 16 h with the same compounds as in A. CAT levels were determined and normalized against nontreated control cells. Except for the previously unpublished results of clotrimazole, RU-486, and TCPOBOP, data are adapted from ref. 19. (C) Activation pattern of CYP2H1 mRNA. LMH cells were treated with the compounds used in A and B for 16 h. Total RNA was isolated and reverse-transcribed. Relative mRNA levels of CYP2H1 standardized against glyceraldehyde-3-phosphate dehydrogenase levels were obtained by semiquantitative PCR using the Taqman system. Values are the average of three independent experiments and error bars represent standard deviations.