Figure 6.

EZH2 and HDAC inhibitors increase H3K27ac expression levels in the BIM gene promoter and enhancers in triple negative breast cancer cells. (A) University of California at Santa Cruz genome browser screen shots display ChIP-seq signals of H3K27ac, the enhancer histone mark H3K4me1 and the promoter histone mark H3K4me3 obtained from the public data generated from a different cancer cell type (prostate cancer LNCaP cells). Reverse transcription-quantitative polymerase chain reaction analysis of ChIP DNA using (B) primers for the promoter, (C) putative enhancer-1 and (D) enhancer-2. DNA was immunoprecipitated by control IgG or anti-H3K27ac antibody from MDA-MB-231 and MDA-MB-436 cells treated with vehicle (DMSO), GSK126, LBH 589 or both GSK126 and LBH589. Cells were harvested for ChIP assay at 24 h after treatment. *P<0.05, **P<0.005 compared with the control (DMSO) group. H3K27me1, histone H3 Lys²⁷ methylation; H3K27me3, histone H3 Lys²⁷ trimethylation; H3K27ac, histone H3 Lys²⁷ acetylation; EZH2, enhancer of zeste 2 polycomb repressive complex 2 subunit; HDAC, histone deacetylase; DMSO, dimethyl sulfoxide; BIM/BCL211, B cell lymphoma-2 like 11; GSK, GSK126; LBH, LBH 589; G+L, GSK126 and LBH 589; ChIP, chromatin immunoprecipitation; IgG, immunoglobulin G.