Figure 6: PEITC-induced hypomethylation and down-regulation of PcG complex expression.

(a) Western blot analysis of PcG complex proteins in SW620 or SW480 cells after 6 weeks treatment with DMSO (C) or 2.5 μM PEITC (P). (b) Western blot analysis of PcG complex proteins in HCT116, SW620, or SW480 cells treated with various concentrations of PEITC for 48 h. (c) Experimental scheme of methylated DNA immunoprecipitation (MeDIP) analysis. Genomic DNA was extracted from SW620-CON or SW620-PEITC cells and then immunoprecipitated using the methylation-specific antibody 5 mC. Genes that overlapped with PcG targets and displayed differential methylation between the immunoprecipitates of SW620-CON and SW620-PEITC cells were then subjected to amplification using MeDIP-specific PCR primers that covered CpG island regions and potentially methylated sequences (d). Primers used are detailed in Supplementary Table 5. IN, input; IP, immunoprecipitation.