Small Molecules Revealed in a Screen Targeting Epithelial Scattering Are Inhibitors of Microtubule Polymerization

J Biomol Screen. 2016 Aug;21(7):671-9. doi: 10.1177/1087057116651850. Epub 2016 May 31.

Abstract

Stimulation of cultured epithelial cells with scatter factor/hepatocyte growth factor (HGF) results in the detachment of cell-cell junctions and initiation of cell migration. Instead of coordinating collective cell behavior within a tissue, cells become solitary and have few cell-cell interactions. Since epithelial scattering is recapitulated in cancer progression and since HGF signaling drives cancer metastasis in many cases, inhibitors of HGF signaling have been proposed to act as anticancer agents. We previously sought to better understand critical components required for HGF-induced epithelial scattering by performing a forward chemical genetics screen, which resulted in the identification of compounds with no previously reported biological activity that we report here. In efforts to determine the mechanism of these compounds, we find that many compounds have broad antiproliferative effects on cancer cell lines by arrest of cell division in G2/M with minimal induction of apoptosis. This effect is reminiscent of microtubule-targeting agents, and we find that several of these scaffolds directly inhibit microtubule polymerization. Compounds are assessed for their toxicity and pharmacokinetics in vivo. The identification of novel small-molecule inhibitors of microtubule polymerization highlights the role of the microtubule cytoskeleton in HGF-induced epithelial scattering.

Keywords: cell-based assays; microtubule; oncology; phenotypic drug discovery.

MeSH terms

  • Antineoplastic Agents / isolation & purification*
  • Antineoplastic Agents / therapeutic use
  • Apoptosis / drug effects
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Epithelial Cells / drug effects
  • Hepatocyte Growth Factor / antagonists & inhibitors*
  • Hepatocyte Growth Factor / genetics
  • High-Throughput Screening Assays / methods*
  • Humans
  • Intercellular Junctions / drug effects
  • Microtubules / drug effects
  • Neoplasm Metastasis
  • Neoplasms / drug therapy*
  • Neoplasms / pathology
  • Polymerization / drug effects
  • Signal Transduction / drug effects
  • Small Molecule Libraries / chemistry*
  • Small Molecule Libraries / pharmacology

Substances

  • Antineoplastic Agents
  • HGF protein, human
  • Small Molecule Libraries
  • Hepatocyte Growth Factor