Epigenetic profiles of the breast cancer cell lines mcf-7 and mda-mb-23

CAMPOY, E; LAURITO, S; MARZESE, DM; MAYORGA, LS; ROQUE, M

Mendoza

Congreso; 48º SAIB; 2012

SAIB

Breast cancer is a heterogeneous disease in which genetic and epigenetic alterations are accumulated. One of the most studied epigenetic alterations is the aberrant DNA methylation of CpG islands. In this work, we aimed to define a 55 genes based methylation profile for 2 human breast cancer cell lines, MCF-7 and MDA-MB-231 and a human chronic myelogenous leukemia derived cell line, K-562. In order to examine aberrant promoter methylation, we have used a multigene approach called Methylation-Specific Multiplex Ligation-dependent Probe Amplification. We have determined a methylation profile of the three cell lines (107 CpG islands). Moreover, a copy number analysis was performed. Previous observations of our group in breast carcinomas had identified the methylation of WT1 gene as the most frequent epigenetic alteration in our population. In concordance with this, we observed a high methylation level of WT1 in both MCF-7 and MDA-MB-231 and absence of this alteration in K-562 cells. By Real-Time PCR we confirmed that WT1 is silenced when the promoter is methylated. The establishment of the methylation profiles of MCF-7 and MDA-MB- 231 cell lines can contribute to future drug sensitivity studies. Epigenetic detections in frozen human breast tumors can be tested as possible predictive markers, by drug sensitivity assays on these cell lines