Aurora kinase A inhibition leads to p73-dependent apoptosis in p53-deficient cancer cells

Cancer Res. 2008 Nov 1;68(21):8998-9004. doi: 10.1158/0008-5472.CAN-08-2658.

Abstract

We investigated the role of Aurora kinase A (AURKA) in regulating p73-dependent apoptosis using the p53-deficient cancer cell lines H1299, TE7, and HCT116p53(-/-). Overexpression of AURKA led to down-regulation of the TAp73-induced activation of the p53/p73-dependent luciferase reporter plasmid (pG13-luc). The reduction in the TAp73 transcription activity was confirmed by measuring the activity of luciferase reporters for p21/WAF1, and PUMA. The siRNA knockdown of endogenous AURKA reversed these effects and Western blot analysis showed a significant increase in the protein level of TAp73 and its downstream transcription targets, PUMA, NOXA, and p21/WAF1. The coexpression of AURKA together with TAp73 inhibited the activation of the pG13-luc, PUMA-luc, and p21/WAF1-luc reporter plasmids with reduction in the protein levels of TAp73 transcription targets. Treatment with AURKA-selective small molecule inhibitor MLN8054 led to a significant increase in the activities of pG13-luc, PUMA-luc, and p21/WAF1-luc reporter plasmids. This effect was accompanied by a significant increase in the mRNA and protein levels of several TAp73 transcription targets: p21/WAF1, PUMA, and NOXA. Flow cytometry cell cycle analysis, after MLN8054 treatment, showed more than a 2-fold increase in cell death. The apoptotic outcome was corroborated by showing an increase in cleaved caspase-3 protein levels by Western blot. Using terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling assay, we showed that the expression of dominant-negative mutant TAp73 expression plasmid (p73DD) counteracted the MLN8054-induced cell death. Taken together, our results indicate that AURKA regulates TAp73-dependent apoptosis and highlight the potential of the AURKA inhibitor MLN8054 in treating cancers that are defective in p53 signaling.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Apoptosis / physiology*
  • Aurora Kinase A
  • Aurora Kinases
  • Benzazepines / pharmacology
  • Blotting, Western
  • Cell Line, Tumor
  • DNA-Binding Proteins / physiology*
  • Humans
  • In Situ Nick-End Labeling
  • Nuclear Proteins / physiology*
  • Phosphorylation
  • Protein Kinase Inhibitors / pharmacology
  • Protein Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein Serine-Threonine Kinases / metabolism
  • Transcription, Genetic
  • Tumor Protein p73
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / physiology*
  • Tumor Suppressor Proteins / physiology*

Substances

  • Benzazepines
  • DNA-Binding Proteins
  • MLN8054
  • Nuclear Proteins
  • Protein Kinase Inhibitors
  • TP73 protein, human
  • Tumor Protein p73
  • Tumor Suppressor Protein p53
  • Tumor Suppressor Proteins
  • AURKA protein, human
  • Aurora Kinase A
  • Aurora Kinases
  • Protein Serine-Threonine Kinases