Discovery of an in vivo chemical probe of the lysine methyltransferases G9a and GLP

J Med Chem. 2013 Nov 14;56(21):8931-42. doi: 10.1021/jm401480r. Epub 2013 Oct 31.


Among epigenetic "writers", "readers", and "erasers", the lysine methyltransferases G9a and GLP, which catalyze mono- and dimethylation of histone H3 lysine 9 (H3K9me2) and nonhistone proteins, have been implicated in a variety of human diseases. A "toolkit" of well-characterized chemical probes will allow biological and disease hypotheses concerning these proteins to be tested in cell-based and animal models with high confidence. We previously discovered potent and selective G9a/GLP inhibitors including the cellular chemical probe UNC0638, which displays an excellent separation of functional potency and cell toxicity. However, this inhibitor is not suitable for animal studies due to its poor pharmacokinetic (PK) properties. Here, we report the discovery of the first G9a and GLP in vivo chemical probe UNC0642, which not only maintains high in vitro and cellular potency, low cell toxicity, and excellent selectivity, but also displays improved in vivo PK properties, making it suitable for animal studies.

Publication types

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

MeSH terms

  • Animals
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Drug Screening Assays, Antitumor
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Histocompatibility Antigens / metabolism
  • Histone-Lysine N-Methyltransferase / antagonists & inhibitors*
  • Histone-Lysine N-Methyltransferase / metabolism
  • Humans
  • Male
  • Mice
  • Molecular Structure
  • Quinazolines / chemical synthesis
  • Quinazolines / chemistry
  • Quinazolines / pharmacology*
  • Structure-Activity Relationship


  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Histocompatibility Antigens
  • Quinazolines
  • UNC0642
  • EHMT1 protein, human
  • EHMT2 protein, human
  • Histone-Lysine N-Methyltransferase