Methylation profiling of leukemia cell lines

Methylation of CpG islands is associated with transcriptional repression and, in cancer, leads to the abnormal silencing of tumor-suppressor genes. We developed a novel and robust technique that allows the unbiased, genome wide detection of CpG-methylation in limited DNA samples, without applying methylation-sensitive restriction endonucleases or bisulfite-treatment. The approach is based on a recombinant, methyl-CpG binding protein that efficiently binds CpG-methylated DNA depending on its degree of CpG methylation. Its application in methyl-CpG immunoprecipitation (MCIp) facilitates the monitoring of CpG-island methylation on a genome wide level (in combination with CpG-island microarrays). The power of this novel approach was demonstrated by the profiling of three myeloid cell lines leading to the identification of more than a hundred aberrantly methylated CpG islands and many novel, putative tumor-suppressor genes. Keywords: MCIp on Chip The methylation profiles of the three leukemia cell lines KG-1, U937 and THP-1 were compared to normal human blood monocytes (reference). The set includes three independent hybridizations for each sample.