Ashwagandha derived withanone targets TPX2-Aurora A complex: computational and experimental evidence to its anticancer activity

PLoS One. 2012;7(1):e30890. doi: 10.1371/journal.pone.0030890. Epub 2012 Jan 27.

Abstract

Cancer is largely marked by genetic instability. Specific inhibition of individual proteins or signalling pathways that regulate genetic stability during cell division thus hold a great potential for cancer therapy. The Aurora A kinase is a Ser/Thr kinase that plays a critical role during mitosis and cytokinesis and is found upregulated in several cancer types. It is functionally regulated by its interactions with TPX2, a candidate oncogene. Aurora A inhibitors have been proposed as anticancer drugs that work by blocking its ATP binding site. This site is common to other kinases and hence these inhibitors lack specificity for Aurora A inhibition in particular, thus advocating the need of some alternative inhibition route. Previously, we identified TPX2 as a cellular target for withanone that selectively kill cancer cells. By computational approach, we found here that withanone binds to TPX2-Aurora A complex. In experiment, withanone treatment to cancer cells indeed resulted in dissociation of TPX2-Aurora A complex and disruption of mitotic spindle apparatus proposing this as a mechanism of the anticancer activity of withanone. From docking analysis, non-formation/disruption of the active TPX2-Aurora A association complex could be discerned. Our MD simulation results suggesting the thermodynamic and structural stability of TPX2-Aurora A in complex with withanone further substantiates the binding. We report a computational rationale of the ability of naturally occurring withanone to alter the kinase signalling pathway in an ATP-independent manner and experimental evidence in which withanone cause inactivation of the TPX2-Aurora A complex. The study demonstrated that TPX2-Aurora A complex is a target of withanone, a potential natural anticancer drug.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Aurora Kinases
  • Biological Assay
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Cluster Analysis
  • Drug Screening Assays, Antitumor
  • Female
  • Gene Expression Regulation, Enzymologic / drug effects
  • Humans
  • Microtubule-Associated Proteins / chemistry
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Molecular Dynamics Simulation*
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Plant Extracts
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reproducibility of Results
  • Reverse Transcriptase Polymerase Chain Reaction
  • Triterpenes / chemistry
  • Triterpenes / pharmacology*
  • Withania / chemistry*
  • Withanolides

Substances

  • Antineoplastic Agents
  • Cell Cycle Proteins
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • Plant Extracts
  • RNA, Messenger
  • TPX2 protein, human
  • Triterpenes
  • Withanolides
  • Aurora Kinases
  • Protein Serine-Threonine Kinases
  • withanone
  • Ashwagandha