Improvement of Oral Bioavailability of Pyrazolo-Pyridone Inhibitors of the Interaction of DCN1/2 and UBE2M

J Med Chem. 2021 May 13;64(9):5850-5862. doi: 10.1021/acs.jmedchem.1c00035. Epub 2021 May 4.


The cullin-RING ubiquitin ligases (CRLs) are ubiquitin E3 enzymes that play a key role in controlling proteasomal degradation and are activated by neddylation. We previously reported inhibitors that target CRL activation by disrupting the interaction of defective in cullin neddylation 1 (DCN1), a CRL neddylation co-E3, and UBE2M, a neddylation E2. Our first-generation inhibitors possessed poor oral bioavailability and fairly rapid clearance that hindered the study of acute inhibition of DCN-controlled CRL activity in vivo. Herein, we report studies to improve the pharmacokinetic performance of the pyrazolo-pyridone inhibitors. The current best inhibitor, 40, inhibits the interaction of DCN1 and UBE2M, blocks NEDD8 transfer in biochemical assays, thermally stabilizes cellular DCN1, and inhibits anchorage-independent growth in a DCN1 amplified squamous cell carcinoma cell line. Additionally, we demonstrate that a single oral 50 mg/kg dose sustains plasma exposures above the biochemical IC90 for 24 h in mice.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Oral
  • Animals
  • Binding Sites
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Crystallography, X-Ray
  • Drug Design
  • Drug Stability
  • Half-Life
  • Humans
  • Intracellular Signaling Peptides and Proteins / antagonists & inhibitors
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Mice
  • Molecular Dynamics Simulation
  • Pyrazoles / chemistry*
  • Pyrazoles / metabolism
  • Pyrazoles / pharmacology
  • Pyridines / chemistry*
  • Pyridines / metabolism
  • Pyridines / pharmacology
  • Structure-Activity Relationship
  • Ubiquitin-Conjugating Enzymes / antagonists & inhibitors
  • Ubiquitin-Conjugating Enzymes / metabolism*


  • DCUN1D1 protein, human
  • Intracellular Signaling Peptides and Proteins
  • Pyrazoles
  • Pyridines
  • pyrazolopyridine
  • Ubiquitin-Conjugating Enzymes
  • UBE2M protein, human