Synthesis and biological evaluation of benzimidazole derivatives as the G9a Histone Methyltransferase inhibitors that induce autophagy and apoptosis of breast cancer cells

Bioorg Chem. 2017 Jun;72:168-181. doi: 10.1016/j.bioorg.2017.04.005. Epub 2017 Apr 17.

Abstract

G9a (also known as KMT1C or EHMT2) is initially identified as a H3K9 methyltransferase that specifically mono- and dimethylates 'Lys-9' of histone H3 (H3K9me1 and H3K9me2, respectively) in euchromatin. It is overexpressed in various human cancers and employed as a promising target in cancer therapy. We discovered a benzoxazole scaffold through virtual high-throughput screening, and designed, synthesized 24 derivatives and investigated for inhibition of G9a. After several rounds of kinase and anti-proliferative activity screening, we discovered a potent G9a antagonist (GA001) with an IC50 value of 1.32μM that could induce autophagy via AMPK in MCF7 cells. In addition, we found high concentration of GA001 could induce apoptosis via p21-Bim signal cascades in MCF7 cells. Our results highlight a new approach for the development of a novel drug targeting G9a with a potential to induce autophagy and apoptosis for future breast cancer therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Autophagy / drug effects*
  • Benzimidazoles / chemical synthesis
  • Benzimidazoles / chemistry
  • Benzimidazoles / pharmacology*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / pathology
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Histocompatibility Antigens / metabolism
  • Histone-Lysine N-Methyltransferase / antagonists & inhibitors*
  • Histone-Lysine N-Methyltransferase / metabolism
  • Humans
  • MCF-7 Cells
  • Models, Molecular
  • Molecular Structure
  • Structure-Activity Relationship

Substances

  • Antineoplastic Agents
  • Benzimidazoles
  • Enzyme Inhibitors
  • Histocompatibility Antigens
  • benzimidazole
  • EHMT2 protein, human
  • Histone-Lysine N-Methyltransferase