Virtual High-Throughput Screening To Identify Novel Activin Antagonists

J Med Chem. 2015 Jul 23;58(14):5637-48. doi: 10.1021/acs.jmedchem.5b00753. Epub 2015 Jul 7.


Activin belongs to the TGFβ superfamily, which is associated with several disease conditions, including cancer-related cachexia, preterm labor with delivery, and osteoporosis. Targeting activin and its related signaling pathways holds promise as a therapeutic approach to these diseases. A small-molecule ligand-binding groove was identified in the interface between the two activin βA subunits and was used for a virtual high-throughput in silico screening of the ZINC database to identify hits. Thirty-nine compounds without significant toxicity were tested in two well-established activin assays: FSHβ transcription and HepG2 cell apoptosis. This screening workflow resulted in two lead compounds: NUCC-474 and NUCC-555. These potential activin antagonists were then shown to inhibit activin A-mediated cell proliferation in ex vivo ovary cultures. In vivo testing showed that our most potent compound (NUCC-555) caused a dose-dependent decrease in FSH levels in ovariectomized mice. The Blitz competition binding assay confirmed target binding of NUCC-555 to the activin A:ActRII that disrupts the activin A:ActRII complex's binding with ALK4-ECD-Fc in a dose-dependent manner. The NUCC-555 also specifically binds to activin A compared with other TGFβ superfamily member myostatin (GDF8). These data demonstrate a new in silico-based strategy for identifying small-molecule activin antagonists. Our approach is the first to identify a first-in-class small-molecule antagonist of activin binding to ALK4, which opens a completely new approach to inhibiting the activity of TGFβ receptor superfamily members. in addition, the lead compound can serve as a starting point for lead optimization toward the goal of a compound that may be effective in activin-mediated diseases.

Publication types

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

MeSH terms

  • Activins / antagonists & inhibitors*
  • Activins / chemistry
  • Activins / metabolism
  • Animals
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Crystallography, X-Ray
  • Drug Evaluation, Preclinical
  • Female
  • Follicle Stimulating Hormone / antagonists & inhibitors
  • Hep G2 Cells
  • High-Throughput Screening Assays*
  • Humans
  • Mice
  • Molecular Docking Simulation
  • Ovary / cytology
  • Ovary / drug effects
  • Protein Conformation
  • Signal Transduction / drug effects
  • User-Computer Interface*


  • activin A
  • Activins
  • Follicle Stimulating Hormone