Epigenetics of breast cancer: DNA methylome and global histone modifications

Abstract

Breast cancer, a heterogeneous disease comprised of tumors with different histological characteristics and clinical outcomes, is the leading cause of cancer deaths in women. Heterogeneous nature of the breast cancer demands delicate approaches to diagnose and follow the most appropriate strategy for clinical management. Based on microarray analysis of mRNA expression, four main molecular subtypes were identified: (a) luminal A, (b) luminal B, (c) basal-like, and (d) ERBB2(+). Even though molecular subtypes provided novel insights into our understanding of breast cancer heterogeneity, there is still room for improvement for better diagnostic, prognostic and therapeutic approaches. In this sense, epigenetics, specifically DNA methylation and histone modifications, have emerged as prominent candidates since several epigenetic factors were observed to be recurrently mutated in cancers including breast cancer. Recent advances in the field implicated that DNA methylation profiles and histone modifications are strongly associated with breast tumor subtypes and patient prognosis. Therefore, understanding contributions of epigenetics to breast cancer biology will lead to better diagnostic and prognostic strategies and will enable development of novel therapeutic approaches. © Springer International Publishing Switzerland 2016.