Design, Synthesis, and Biological Evaluation of 1-Methyl-1,4-dihydroindeno[1,2-c]pyrazole Analogues as Potential Anticancer Agents Targeting Tubulin Colchicine Binding Site

J Med Chem. 2016 Jun 9;59(11):5341-55. doi: 10.1021/acs.jmedchem.6b00071. Epub 2016 May 20.

Abstract

By targeting a new binding region at the interface between αβ-tubulin heterodimers at the colchicine binding site, we designed a series of 7-substituted 1-methyl-1,4-dihydroindeno[1,2-c]pyrazoles as potential tubulin polymerization inhibitors. Among the compounds synthesized, 2-(6-ethoxy-3-(3-ethoxyphenylamino)-1-methyl-1,4-dihydroindeno[1,2-c]pyrazol-7-yloxy)acetamide 6a and 2-(6-ethoxy-3-(3-ethoxyphenylamino)-1-methyl-1,4-dihydroindeno[1,2-c]pyrazol-7-yloxy)-N-hydroxyacetamide 6n showed noteworthy low nanomolar potency against HepG2, Hela, PC3, and MCF-7 cancer cell lines. In mechanism studies, 6a inhibited tubulin polymerization and disorganized microtubule in A549 cells by binding to tubulin colchicine binding site. 6a arrested A549 cells in G2/M phase that was related to the alterations in the expression of cyclin B1 and p-cdc2. 6a induced A549 cells apoptosis through the activation of caspase-3 and PARP. In addition, 6a inhibited capillary tube formation in a concentration-dependent manner. In nonsmall cell lung cancer xenografts mouse model, 6a suppressed tumor growth by 59.1% at a dose of 50 mg/kg (ip) without obvious toxicity, indicating its in vivo potential as anticancer agent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Binding Sites / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Colchicine / chemistry
  • Colchicine / metabolism*
  • Dose-Response Relationship, Drug
  • Drug Design*
  • Drug Screening Assays, Antitumor
  • Humans
  • Mice
  • Mice, Nude
  • Models, Molecular
  • Molecular Structure
  • Neoplasms, Experimental / drug therapy
  • Neoplasms, Experimental / pathology
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry
  • Pyrazoles / pharmacology*
  • Structure-Activity Relationship
  • Tubulin / chemistry
  • Tubulin / metabolism*
  • Tubulin Modulators / chemical synthesis
  • Tubulin Modulators / chemistry
  • Tubulin Modulators / pharmacology*

Substances

  • 1-methyl-1,4-dihydroindeno(1,2-c)pyrazole
  • Antineoplastic Agents
  • Pyrazoles
  • Tubulin
  • Tubulin Modulators
  • Colchicine