Fig. 4

CLDN6 was down-regulated via recruiting MeCP2 and deacetylating H3Ac and H4Ac for DNA methylation stability. a The molecular size of shared genomic DNA of MCF-7 cells treated with DMSO (as control) and 5-aza-dC. b Effect of 5-aza-dC on binding of MeCP2 to CLDN6 was analyzed using ChIP assay. The binding of RNA polymerase II and IgG to the GAPDH promoter was used as a positive or a negative control. c Quantitative analysis of images presented in (b). d Analysis of CLDN6 promoter occupancy by H3Ac and H4Ac. ChIP was used to analyze the interactions of H3Ac and H4Ac with the CLDN6 proximal promoter in MCF-7 cells treated with 20 μM 5-aza-dC and 125nM TSA for 48 h respectively or synergistically. Effect of 5-aza-dC and TSA on binding of H3Ac and H4Ac to CLDN6 was analyzed using ChIP assay. The binding of RNA polymerase II and IgG to the GAPDH promoter was used as a positive and a negative control. e Quantitative analysis of images presented in (d). *P < 0.05. CLDN6, claudin-6; 5-aza-dC, 5-Aza-2’-deoxycytidine; TSA, Trichostatin A; MeCP2, methyl-CpG-binding protein 2; H3Ac, Histone 3 acetylation; H4Ac, Histone 4 acetylation