5-aza treatment of breast cancer and non-tumorigenic breast cells

CpG hypermethylation in gene promoters is a frequent mechanism of tumor suppressor gene silencing in various types of cancers. 5-aza-2'-deoxycytidine (AZA) is a DNA demethylating and anti-cancer agent resulting in induction of genes suppressed via DNA hypermethylation. Using microarray expression profiling of AZA or DMSO treated and untreated breast cancer (MCF7 and MDA-MB-231) and non-tumorigenic breast (NTB) cells, we aim to identify candidate genes that are downregulated via promoter hypermethylation in breast cancer. MCF7, MDA-MB-231 and MCF12A cell lines were treated with 5µM of 5-aza-2'-deoxycytidine, for 4 days, with everyday drug refreshments. AT the end of 96th hour, cells were harvested, RNA isolation was performed and standard protocol was followed for hybridization to Affymetrix Hgu-133 Plus 2.0 arrays.