EPIGENETIC MODIFICATIONS OF p16, E-CADHERIN, RARβ AND DAPK GENEPROMOTERS IN BREAST CANCER

摘要

The breast cancer is the result of multiple associations of genetic and epigenetic alterations, whichlead to overexpression of the proto-oncogenes and loss of expression of tumor suppressor genes. Suchnew expression patterns determine the cell genetic reprogramming results in the oncogenesis processand therefore may represent possible important markers for diagnostic and prognostic in cancertherapy. The epigenetic process is frequently associated with the aberrant silencing of tumorsuppressor genes through the CpG islands located in their promoter region. These regions arenormally unmethylated while in tumor cells are abnormally hypermethylated and associated withtranscriptional silencing. Such local hypermethylation processes represent frequently an alternativemechanism for mutations of tumor suppressor genes, being an early and ordinary process for manytumor types, including breast cancer. The aim of this study is to analyze the promoter methylation pattern of some tumor suppressor genes(p1 6, E-cadherin, RARβ and DAPK) in invasive ductal breast cancers, in order to identify newmolecular markers for diagnosis and prognosis.