Figure 5.

FXR is recruited to the cyclin D1 promoter and promotes its transcription. A ChIP assay was performed in H1975 and H1299 cells with anti-human FXR mouse monoclonal antibody and primer sets described in the “Materials and methods” section. The isotype IgG was used as a negative control (NC), and the input chromatin sample was used as a positive control. (A) Representative PCR amplification products are shown. Enrichment of FXR protein in the putative motif of CCND1 promoter in H1975 (B) and H1299 (C) cells was determined relative to input samples, respectively. (D) Schematic representation of a wild-type CCND1 reporter plasmid (pGL3-CCND1 FXRE-wt) and an FXRE-deleted CCND1 reporter plasmid (pGL3-CCND1 FXRE-deleted). (E) H1975 cells were transfected with NCsiRNA or FXRsiRNA-2; (F) HCC4006 stable cell lines were treated with or without Z-guggulsterone (Z-gu, 40 μM). One day later, all cells were transfected with the indicated reporter plasmids and then collected for measurements of the luciferase activities at 24 h post-transfection. The data were presented as the mean ± SD of at least three independent experiments. *p < 0.05.