Figure 6.

Overexpression and DNA hypomethylation of MMP12 in human HepG2 HCC cells is accompanied by TET1 increased occupancy at MMP12 promoter region. (a-b) Expression of MMP12 in human HepG2 HCC cells and in human primary hepatocytes (NorHep), as measured by qRT-PCR (a) and western blot (b). In western blot analyses, reactive bands were visualized using the chemiluminescent protocol in the ChemiDoc MP Imaging System (Bio-Rad) and analysed using the Image Lab software. Protein loading was normalized with respect to total sample protein loaded using free stain gels. (c) DNA methylation levels across three CpG sites within MMP12 promoter region in HepG2 and NorHep, as measured by pyrosequencing. (d) TET1 binding within MMP12 promoter region in HepG2 and NorHep, as measured by quantitative chromatin immunoprecipitation (qChIP). (e) Number of HepG2 and NorHep cells that invaded through extracellular matrix within 24 hr, as assessed by Boyden chamber invasion assay. Results are expressed as mean ± SD; n = 3, ***P < 0.001.