Expression 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. Genome wide methylation profiling of myeloid leukemia cell lines identified a large number of genes with aberrantly methylated CpG islands. Comparative mRNA expression analysis suggests that more than half of these genes show extremely low or absent expression in normal cells, suggesting that hypermethylation in cancer may be independent of the transcriptional status of the affected gene. Keywords: comparison of expression status and CpG methylation status The expression profiles of the three leukemia cell lines KG-1, U937 and THP-1 was compared to normal human blood monocytes (reference). The set includes a single hybridization for each sample.