CHD4 Promotes Breast Cancer Progression as a Coactivator of Hypoxia-Inducible Factors

Cancer Res. 2020 Sep 15;80(18):3880-3891. doi: 10.1158/0008-5472.CAN-20-1049. Epub 2020 Jul 22.

Abstract

Recruitment of RNA polymerase II to hypoxia-inducible factor (HIF) target genes under normoxia is a prerequisite for HIF-mediated transactivation. However, the underlying mechanism of this recruitment remains unknown. Here we report that chromodomain helicase DNA-binding protein 4 (CHD4) physically interacts with α and β subunits of HIF1 and HIF2 and enhances HIF-driven transcriptional programs to promote breast cancer progression. Loss of HIF1/2α abolished CHD4-mediated breast tumor growth in mice. In breast cancer cells under normoxia, CHD4 enrichment at HIF target gene promoters increased RNA polymerase II loading through p300. Hypoxia further promoted CHD4 binding to the chromatin via HIF1/2α, where CHD4 in turn enhanced recruitment of HIF1α, leading to HIF target gene transcription. CHD4 was upregulated and correlated with HIF target gene expression in human breast tumors; upregulation of CHD4 and other known HIF coactivators in human breast tumors was mutually exclusive. Furthermore, CHD4 was associated with poor overall survival of patients with breast cancer. Collectively, these findings reveal a new fundamental mechanism of HIF regulation in breast cancer, which has clinical relevance. SIGNIFICANCE: This study identifies CHD4 as a HIF coactivator and elucidates the fundamental mechanism underlying CHD4-mediated HIF transactivation in breast tumors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Chromatin Immunoprecipitation / methods
  • Disease Progression*
  • Female
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Mi-2 Nucleosome Remodeling and Deacetylase Complex / metabolism*
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplasm Invasiveness
  • RNA Polymerase II / metabolism
  • Transcriptional Activation
  • Tumor Hypoxia

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • CHD4 protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • endothelial PAS domain-containing protein 1
  • RNA Polymerase II
  • Mi-2 Nucleosome Remodeling and Deacetylase Complex