Polyheteroaryl Oxazole/Pyridine-Based Compounds Selected in Vitro as G-Quadruplex Ligands Inhibit Rock Kinase and Exhibit Antiproliferative Activity

J Med Chem. 2018 Dec 13;61(23):10502-10518. doi: 10.1021/acs.jmedchem.8b01023. Epub 2018 Dec 3.

Abstract

Heptaheteroaryl compounds comprised of oxazole and pyridine units (TOxaPy) are quadruplex DNA (G4)-interactive compounds. Herein, we report on the synthesis of parent compounds bearing either amino side chains (TOxaPy-1-5) or featuring an isomeric oxazole-pyridine central connectivity (iso-TOxapy, iso-TOxapy 1-3) or a bipyridine core (iso-TOxabiPy). The new isomeric series showed significant G4-binding activity in vitro, and remarkably, three compounds (iso-TOxaPy, iso-TOxaPy-1, and iso-TOxabiPy) exhibited high antiproliferative activity toward a tumor panel of cancer cell lines. However, these compounds do not behave as typical G-quadruplex (G4) binders, and the kinase profiling assay revealed that the best antiproliferative molecule iso-TOxaPy selectively inhibited Rock-2. The targeting of Rock kinase was confirmed in cells by the dephosphorylation of Rock-2 substrates, the decrease of stress fibers, and peripheral focal adhesions, as well as the induction of long neurite-like extensions. Remarkably, two of these molecules were able to inhibit the growth of cells organized as spheroids.

MeSH terms

  • Cell Proliferation / drug effects
  • Drug Design*
  • G-Quadruplexes / drug effects*
  • HeLa Cells
  • Humans
  • Ligands
  • Oxazoles / chemistry*
  • Oxazoles / metabolism
  • Oxazoles / pharmacology*
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Pyridines / chemistry*
  • Structure-Activity Relationship
  • rho-Associated Kinases / antagonists & inhibitors*

Substances

  • Ligands
  • Oxazoles
  • Protein Kinase Inhibitors
  • Pyridines
  • rho-Associated Kinases