Potent and selective caspase-2 inhibitor prevents MDM-2 cleavage in reversine-treated colon cancer cells

Cell Death Differ. 2019 Dec;26(12):2695-2709. doi: 10.1038/s41418-019-0329-2. Epub 2019 Apr 11.


Most caspases can be positioned unambiguously within the regulated cell death networks of apoptosis and pyroptosis, but the role of caspase-2, a highly conserved protease within the family, remains enigmatic. This is mainly due to lack of selective chemical and biochemical tools for the investigation of this protease. In this study, we used our hybrid combinatorial substrate library (HyCoSuL) approach to broadly profile caspase-2 substrate specificity using peptide scanning libraries. This screen uncovered previously unknown caspase-2 peptidyl substrate preferences, which were further used to develop caspase-2 selective fluorogenic substrates and covalent, irreversible AOMK inhibitors. Finally, we used the champion inhibitor (NH-23-C2) in reversine-treated HCT-116 colon cancer cells to selectively block caspase-2 activity and caspase-2-mediated MDM-2 cleavage. In addition, we showed that NH-23-C2 does not block caspase-3 or caspase-8, which makes it a powerful chemical tool to dissect the true role of caspase-2 in various biological setups.

Publication types

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

MeSH terms

  • Apoptosis / drug effects
  • Caspase 2 / metabolism*
  • Colonic Neoplasms / drug therapy*
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism*
  • Colonic Neoplasms / pathology
  • Cysteine Endopeptidases / metabolism*
  • Cysteine Proteinase Inhibitors / pharmacology*
  • HCT116 Cells
  • Humans
  • Morpholines / pharmacology
  • Morpholines / therapeutic use*
  • Proto-Oncogene Proteins c-mdm2 / metabolism*
  • Purines / pharmacology
  • Purines / therapeutic use*
  • Substrate Specificity


  • Cysteine Proteinase Inhibitors
  • Morpholines
  • Purines
  • Proto-Oncogene Proteins c-mdm2
  • CASP2 protein, human
  • Caspase 2
  • Cysteine Endopeptidases
  • 2-(4-morpholinoanilino)-6-cyclohexylaminopurine