Aurora kinase A inhibition leads to p73-dependent apoptosis in p53-deficient cancer cells.
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.
Dar
Altaf A
AA
Departments of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Belkhiri
Abbes
A
Ecsedy
Jeffrey
J
Zaika
Alexander
A
El-Rifai
Wael
W
D017209:Apoptosis / Q000502:physiology*; D064096:Aurora Kinase A; D064127:Aurora Kinases; D001552:Benzazepines / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000502:physiology*; D006801:Humans; D020287:In Situ Nick-End Labeling; D009687:Nuclear Proteins / Q000502:physiology*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014158:Transcription, Genetic; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000502:physiology*
D001552:Benzazepines; D004268:DNA-Binding Proteins; C518940:MLN8054; D009687:Nuclear Proteins; D047428:Protein Kinase Inhibitors; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C576917:AURKA protein, human; D064096:Aurora Kinase A; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases