Ligand-dependent genomic function of glucocorticoid receptor in triple-negative breast cancer

Nat Commun. 2015 Sep 16:6:8323. doi: 10.1038/ncomms9323.

Abstract

Glucocorticoids (GCs) have been widely used as coadjuvants in the treatment of solid tumours, but GC treatment may be associated with poor pharmacotherapeutic response or prognosis. The genomic action of GC in these tumours is largely unknown. Here we find that dexamethasone (Dex, a synthetic GC)-regulated genes in triple-negative breast cancer (TNBC) cells are associated with drug resistance. Importantly, these GC-regulated genes are aberrantly expressed in TNBC patients and are associated with unfavourable clinical outcomes. Interestingly, in TNBC cells, Compound A (CpdA, a selective GR modulator) only regulates a small number of genes not involved in carcinogenesis and therapy resistance. Mechanistic studies using a ChIP-exo approach reveal that Dex- but not CpdA-liganded glucocorticoid receptor (GR) binds to a single glucocorticoid response element (GRE), which drives the expression of pro-tumorigenic genes. Our data suggest that development of safe coadjuvant therapy should consider the distinct genomic function between Dex- and CpdA-liganded GR.

Publication types

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

MeSH terms

  • Acetates / pharmacology*
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Cell Proliferation / genetics
  • Chromatin Immunoprecipitation
  • Dexamethasone / pharmacology*
  • Drug Resistance, Neoplasm / drug effects*
  • Drug Resistance, Neoplasm / genetics
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Neoplastic*
  • Glucocorticoids / pharmacology*
  • Humans
  • Ligands
  • Paclitaxel / pharmacology
  • Receptors, Glucocorticoid / drug effects*
  • Receptors, Glucocorticoid / genetics
  • Response Elements
  • Reverse Transcriptase Polymerase Chain Reaction
  • Triple Negative Breast Neoplasms / genetics*
  • Tyramine / analogs & derivatives*
  • Tyramine / pharmacology

Substances

  • 2-(4-acetoxyphenyl)-2-chloro-N-methylethylamine
  • Acetates
  • Glucocorticoids
  • Ligands
  • NR3C1 protein, human
  • Receptors, Glucocorticoid
  • Dexamethasone
  • Paclitaxel
  • Tyramine

Associated data

  • GEO/GSE56022