Structure-based discovery of a boronic acid bioisostere of combretastatin A-4

Chem Biol. 2005 Sep;12(9):1007-14. doi: 10.1016/j.chembiol.2005.06.016.

Abstract

Targeting the microtubule system represents an attractive strategy for the development of anticancer agents. In this study, we report a class of combretastatin A-4 (CA-4) analogs derivatized with a boronic acid moiety replacing the hydroxyl group on the C-ring of CA-4. Docking studies of the X-ray structures of our aryl-boronic analogs onto an X-ray structure of the alpha,beta-tubulin heterodimer suggested that cis-6 was a potent inhibitor of the colchicine binding. The model indicated that there would be strong hydrogen bonding between the boronic acid moiety and Thr-179 and Val-181 of alpha-tubulin. We demonstrate that the cis-6 boronic acid bioisostere of CA-4: (1) inhibits tubulin assembly, (2) competitively displaces colchicine, and (3) is a low-nanomolar inhibitor of human cancer cell lines. We present this isostere as a class of potent analogs of CA-4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Phytogenic / chemistry*
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Boronic Acids / chemistry*
  • Cell Line, Tumor
  • Crystallography, X-Ray
  • Humans
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Structure
  • Spectrometry, Mass, Electrospray Ionization
  • Stilbenes / chemistry*
  • Stilbenes / pharmacology

Substances

  • Antineoplastic Agents, Phytogenic
  • Boronic Acids
  • Stilbenes
  • fosbretabulin