Rapid Identification of Novel Allosteric PRC2 Inhibitors

ACS Chem Biol. 2019 Oct 18;14(10):2134-2140. doi: 10.1021/acschembio.9b00468. Epub 2019 Sep 23.

Abstract

Enhancer of zeste homologue 2 (EZH2), the catalytic subunit of polycomb repressive complex 2 (PRC2), regulates chromatin state and gene expression by methylating histone H3 lysine 27. EZH2 is overexpressed or mutated in various hematological malignancies and solid cancers. Our previous efforts to identify inhibitors of PRC2 methyltransferase activity by high-throughput screening (HTS) resulted in large numbers of false positives and thus a significant hit deconvolution challenge. More recently, others have reported compounds that bind to another PRC2 core subunit, EED, and allosterically inhibit EZH2 activity. This mechanism is particularly appealing as it appears to retain potency in cell lines that have acquired resistance to orthosteric EZH2 inhibition. By designing a fluorescence polarization probe based on the reported EED binding compounds, we were able to quickly and cleanly re-triage our previously challenging HTS hit list and identify novel allosteric PRC2 inhibitors.

MeSH terms

  • Allosteric Regulation / drug effects
  • Benzofurans / chemistry*
  • Benzofurans / metabolism
  • Carbocyanines / chemistry
  • Cell Line, Tumor
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / metabolism
  • Fluorescent Dyes / chemistry
  • High-Throughput Screening Assays
  • Humans
  • Ligands
  • Polycomb Repressive Complex 2 / antagonists & inhibitors*
  • Polycomb Repressive Complex 2 / isolation & purification
  • Polycomb Repressive Complex 2 / metabolism
  • Protein Binding
  • Small Molecule Libraries / chemistry*
  • Small Molecule Libraries / metabolism

Substances

  • Alexa Fluor 647
  • Benzofurans
  • Carbocyanines
  • Enzyme Inhibitors
  • Fluorescent Dyes
  • Ligands
  • Small Molecule Libraries
  • Polycomb Repressive Complex 2