Discovery of Novel Spiroindoline Derivatives as Selective Tankyrase Inhibitors

J Med Chem. 2019 Apr 11;62(7):3407-3427. doi: 10.1021/acs.jmedchem.8b01888. Epub 2019 Apr 1.


The canonical WNT pathway plays an important role in cancer pathogenesis. Inhibition of poly(ADP-ribose) polymerase catalytic activity of the tankyrases (TNKS/TNKS2) has been reported to reduce the Wnt/β-catenin signal by preventing poly ADP-ribosylation-dependent degradation of AXIN, a negative regulator of Wnt/β-catenin signaling. With the goal of investigating the effects of tankyrase and Wnt pathway inhibition on tumor growth, we set out to find small-molecule inhibitors of TNKS/TNKS2 with suitable drug-like properties. Starting from 1a, a high-throughput screening hit, the spiroindoline derivative 40c (RK-287107) was discovered as a potent TNKS/TNKS2 inhibitor with >7000-fold selectivity against the PARP1 enzyme, which inhibits WNT-responsive TCF reporter activity and proliferation of human colorectal cancer cell line COLO-320DM. RK-287107 also demonstrated dose-dependent tumor growth inhibition in a mouse xenograft model. These observations suggest that RK-287107 is a promising lead compound for the development of novel tankyrase inhibitors as anticancer agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Cell Line, Tumor
  • Enzyme Inhibitors / pharmacology*
  • High-Throughput Screening Assays
  • Humans
  • Indoles / chemistry*
  • Indoles / pharmacology*
  • Mice
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology
  • Spiro Compounds / chemistry
  • Spiro Compounds / pharmacology*
  • Tankyrases / antagonists & inhibitors*
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Indoles
  • Small Molecule Libraries
  • Spiro Compounds
  • indoline
  • Tankyrases