Discovery of Novel Benzimidazole and Indazole Analogues as Tubulin Polymerization Inhibitors with Potent Anticancer Activities

J Med Chem. 2021 Apr 22;64(8):4498-4515. doi: 10.1021/acs.jmedchem.0c01837. Epub 2021 Mar 31.

Abstract

Novel indazole and benzimidazole analogues were designed and synthesized as tubulin inhibitors with potent antiproliferative activities. Among them, compound 12b exhibited the strongest inhibitory effects on the growth of cancer cells with an average IC50 value of 50 nM, slightly better than colchicine. 12b exhibited nearly equal potency against both, a paclitaxel-resistant cancer cell line (A2780/T, IC50 = 9.7 nM) and the corresponding parental cell line (A2780S, IC50 = 6.2 nM), thus effectively overcoming paclitaxel resistance in vitro. The crystal structure of 12b in complex with tubulin was solved to 2.45 Å resolution by X-ray crystallography, and its direct binding was confirmed to the colchicine site. Furthermore, 12b displayed significant in vivo antitumor efficacy in a melanoma tumor model with tumor growth inhibition rates of 78.70% (15 mg/kg) and 84.32% (30 mg/kg). Collectively, this work shows that 12b is a promising lead compound deserving further investigation as a potential anticancer agent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzimidazoles / chemistry*
  • Benzimidazoles / metabolism
  • Benzimidazoles / therapeutic use
  • Binding Sites
  • Cell Cycle Checkpoints / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Crystallography, X-Ray
  • Disease Models, Animal
  • Drug Design*
  • Drug Resistance, Neoplasm / drug effects
  • Drug Screening Assays, Antitumor
  • Humans
  • Male
  • Melanoma / drug therapy
  • Mice
  • Mice, Inbred BALB C
  • Molecular Dynamics Simulation
  • Structure-Activity Relationship
  • Tubulin / chemistry
  • Tubulin / metabolism
  • Tubulin Modulators / chemistry*
  • Tubulin Modulators / metabolism
  • Tubulin Modulators / pharmacology
  • Tubulin Modulators / therapeutic use

Substances

  • Benzimidazoles
  • Tubulin
  • Tubulin Modulators