Figure 3. ZEB1 binds directly to the DNMT1 promoter and regulates its transcription. (A) Schematic showing the region of the DNMT1 promoter containing potential ZEB1 binding sites. (B) Chromatin immunoprecipitation data from HDFs incubated with either anti-ZEB1antibody or non-specific control IgG, showing the amplification of each of the four predicted ZEB1 binding sites within the DNMT1 promoter (termed DNMT1 b1, 2, 3, and 4). Experiments were performed in triplicate.* vs IgG, P < 0.05;ns vs IgG, P>0.05. (C) Luciferase reporter assay data, showing the activity of either the wild type (WT)DNMT1 promoter or mutants lacking each of the predicted ZEB1 binding sites. Cells were transfected with the following plasmids: ZEB1: ZEB1-cDNA-expressing vector; WT DNMT1: reporter plasmid containing WT DNMT1 promoter; DNMT1 Mut1-4: reporter plasmids containing the DNMT1 promoter with putative ZEB1 binding sites 1-4 deleted. Experiments were performed in triplicate. * vs pCWV-ZEB1+pGL4.1, P<0.05; # vs pCWV-ZEB1+pGL4.1-DNMT1, P <0.05.