In vivo CTCF binding analysis in miR-125b1 locus and the characterization of covalent histone marks in both normal cells and in primary breast tumors. A- Chromatin immunoprecipitation (ChIP) of CTCF and the histone covalent marks analyzed at the human miR-125b1 locus in cells obtained from normal breast tissue (NB 1). B- Characterization of CTCF and histone covalent marks in two tumor samples tissue from different patients (BC8 and BC9), input amplification refers as the entire population of DNA. A non-specific IgG antibody was used as a control. C- Positive controls for the ChIP assay. For CTCF we performed a PCR of the p53 gene promoter region in normal breast (NB1) and two tumor samples (BC8 and BC9); for H3K27me3 we evaluated the abundance of the H3K27me3 histone mark at the Myelin transcription factor 1 distal promoter (MYT1) region in two tumor samples (BC8 and BC9).
Soto-Reyes et al. BMC Cancer 2012 12:40 doi:10.1186/1471-2407-12-40