Combined drug action of 2-phenylimidazo[2,1-b]benzothiazole derivatives on cancer cells according to their oncogenic molecular signatures

PLoS One. 2012;7(10):e46738. doi: 10.1371/journal.pone.0046738. Epub 2012 Oct 5.

Abstract

The development of targeted molecular therapies has provided remarkable advances into the treatment of human cancers. However, in most tumors the selective pressure triggered by anticancer agents encourages cancer cells to acquire resistance mechanisms. The generation of new rationally designed targeting agents acting on the oncogenic path(s) at multiple levels is a promising approach for molecular therapies. 2-phenylimidazo[2,1-b]benzothiazole derivatives have been highlighted for their properties of targeting oncogenic Met receptor tyrosine kinase (RTK) signaling. In this study, we evaluated the mechanism of action of one of the most active imidazo[2,1-b]benzothiazol-2-ylphenyl moiety-based agents, Triflorcas, on a panel of cancer cells with distinct features. We show that Triflorcas impairs in vitro and in vivo tumorigenesis of cancer cells carrying Met mutations. Moreover, Triflorcas hampers survival and anchorage-independent growth of cancer cells characterized by "RTK swapping" by interfering with PDGFRβ phosphorylation. A restrained effect of Triflorcas on metabolic genes correlates with the absence of major side effects in vivo. Mechanistically, in addition to targeting Met, Triflorcas alters phosphorylation levels of the PI3K-Akt pathway, mediating oncogenic dependency to Met, in addition to Retinoblastoma and nucleophosmin/B23, resulting in altered cell cycle progression and mitotic failure. Our findings show how the unusual binding plasticity of the Met active site towards structurally different inhibitors can be exploited to generate drugs able to target Met oncogenic dependency at distinct levels. Moreover, the disease-oriented NCI Anticancer Drug Screen revealed that Triflorcas elicits a unique profile of growth inhibitory-responses on cancer cell lines, indicating a novel mechanism of drug action. The anti-tumor activity elicited by 2-phenylimidazo[2,1-b]benzothiazole derivatives through combined inhibition of distinct effectors in cancer cells reveal them to be promising anticancer agents for further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / pharmacology*
  • Benzothiazoles / administration & dosage
  • Benzothiazoles / adverse effects
  • Benzothiazoles / pharmacology*
  • Cell Cycle / drug effects
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cell Transformation, Neoplastic / drug effects
  • Humans
  • Metabolic Networks and Pathways / drug effects
  • Metabolic Networks and Pathways / genetics
  • Mice
  • Mice, Nude
  • Molecular Targeted Therapy*
  • Mutation, Missense
  • Phosphorylation
  • Protein Interaction Maps
  • Protein Processing, Post-Translational / drug effects
  • Protein Transport / drug effects
  • Proto-Oncogene Proteins c-met / genetics
  • Proto-Oncogene Proteins c-met / metabolism
  • Receptors, Platelet-Derived Growth Factor / metabolism
  • Signal Transduction / drug effects
  • Transcriptome / drug effects*
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents
  • Benzothiazoles
  • Cell Cycle Proteins
  • triflorcas
  • MET protein, human
  • Proto-Oncogene Proteins c-met
  • Receptors, Platelet-Derived Growth Factor

Grants and funding

This work was supported by funds from the INCa (Institut National du Cancer), ARC (Association pour la recherche contre le cancer), FRM (Fondation pour la recherche médicale), FdF (Fondation de France), Fondation Bettencourt-Schueller, Marie Curie Host Fellowship for the Transfer of Knowledge (MTKD-CT-2004-509804), Protisvalor, Valorpaca, and Oséo to FM. This research has been developed within the CM0602 COST Action “Inhibitors of Angiogenesis: design, synthesis and biological exploitation”. AF was supported by the INCa and ARC; NI by Valorpaca, FC by the Italian Association of Cancer Research (ARC) and by Oséo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.