Fig. 4.

FXR expression in response to inhibition of DNA methylation and methyl-DNA immunoprecipitation (MeDIP) analysis of FXR promoter. A: relative mRNA levels of FXR and COL1A2 in HT-29 and SW620 cells treated with 2 μg/ml azacytidine (AZA) for 3 days (n = 3). B: immunoprecipitation of genomic DNA (gDNA) from HT-29 and SW620 cells with antibody against 5-methylated-cytosine (5-mC) followed by quantitative PCR analysis of MeDIP. A CpG island located in COL1A2 promoter (COL1A2 no. 1) was analyzed as a positive control and an unmethylated region (UBE2B) for the negative control (Neg). Values were recorded from replicate PCR reactions and are reported as fold over IgG (y-axis). C: relative mRNA levels of FXR and COL1A2 in SW620 cells after siRNA knockdown of DNMT 1 and 3B compared with negative siRNA controls. Messenger RNA levels of DNMT 1 and DNMT 3B were nearly 20% that of the nonspecific siRNA control. CTLR, nontransfected control. Data are expressed as means ± SE. *P < 0.05.