Epigenetic profile of the breast cancer cell lines, MCF-7 and MDA-MB-231

CAMPOY, EMANUEL MARTIN; LAURITO, SERGIO; MARZESE, DIEGO; MAYORGA, LUIS; ROQUÉ, MARÍA

Mendoza

Congreso; XLVIII Reunión Anual de la SAIB; 2012

Breast cancer is a heterogeneous disease in which genetic and epigenetic alterations are accumulated. These events generate different biological and clinical tumor profiles. One of the epigenetic alterations studied is the aberrant DNA methylation of CpG islands which trigger the silencing of the genes. Changes in DNA methylation have been reported to occur early in carcinogenesis and therefore are potentially important early indicators of existing disease. In this work, we have used stably cell lines derived from metastatic site of the breast adenocarcinoma (MCF-7 and MDA-MB-231) and from chronic myelogenous leukemia (K-562) as a control. In order to examine epigenetic events of aberrant promoter methylation in the mentioned cell lines, we have use a multigene approach called Methylation-Specific Multiplex Ligation-dependent Probe Amplification (MS-MLPA). We have determined a methylation profile of the three cell lines (107 CpG island included in 55 cancer related genes). Moreover, a copy number analysis was perform with the aim of detect deleted or duplicated genes in the cell line genomes. It have been previously described that a gene called Wt1 (Wilms Tumor 1) presents a high methylation frequency in breast cancer tumors. In concordance with this, we observed methylation of the CpG island of Wt1 specifically in the breast cancer cell lines. Also we perform a Real-Time experiment to corroborate the effect of methylation in the silencing of Wt1. We observed not translation of Wt1 in the breast Cancer cell lines in contrast with the leukemic cells.