DNA methylation of oestrogen-regulated enhancers defines endocrine sensitivity in breast cancer

Nat Commun. 2015 Jul 14;6:7758. doi: 10.1038/ncomms8758.

Abstract

Expression of oestrogen receptor (ESR1) determines whether a breast cancer patient receives endocrine therapy, but does not guarantee patient response. The molecular factors that define endocrine response in ESR1-positive breast cancer patients remain poorly understood. Here we characterize the DNA methylome of endocrine sensitivity and demonstrate the potential impact of differential DNA methylation on endocrine response in breast cancer. We show that DNA hypermethylation occurs predominantly at oestrogen-responsive enhancers and is associated with reduced ESR1 binding and decreased gene expression of key regulators of ESR1 activity, thus providing a novel mechanism by which endocrine response is abated in ESR1-positive breast cancers. Conversely, we delineate that ESR1-responsive enhancer hypomethylation is critical in transition from normal mammary epithelial cells to endocrine-responsive ESR1-positive cancer. Cumulatively, these novel insights highlight the potential of ESR1-responsive enhancer methylation to both predict ESR1-positive disease and stratify ESR1-positive breast cancer patients as responders to endocrine therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Agents, Hormonal / therapeutic use
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Carcinoma, Ductal, Breast / drug therapy
  • Carcinoma, Ductal, Breast / genetics*
  • Carcinoma, Ductal, Breast / metabolism
  • Carcinoma, Lobular / drug therapy
  • Carcinoma, Lobular / genetics*
  • Carcinoma, Lobular / metabolism
  • Chromatin Immunoprecipitation
  • DNA Methylation / genetics*
  • Drug Resistance, Neoplasm / genetics*
  • Enhancer Elements, Genetic / genetics*
  • Estrogen Receptor alpha / genetics*
  • Estrogen Receptor alpha / metabolism
  • Female
  • Humans
  • MCF-7 Cells
  • Middle Aged
  • Multiplex Polymerase Chain Reaction
  • Tamoxifen / therapeutic use

Substances

  • Antineoplastic Agents, Hormonal
  • Estrogen Receptor alpha
  • estrogen receptor alpha, human
  • Tamoxifen

Associated data

  • GEO/GSE69118