Aurora A is a negative prognostic factor and a new therapeutic target in human neuroblastoma

Abstract

We studied expression of the Aurora A gene and its clinical significance in a cohort of neuroblastoma patients. In addition, we investigated the antitumor activity of MLN8054, a novel small-molecule inhibitor of Aurora A kinase, on cultured NB cell lines in vitro. Aurora A mRNA expression was assessed by quantitative real-time PCR in tumor tissue specimens from 67 patients at diagnosis and in 9 human neuroblastoma cell lines. Western blot assays for Aurora A protein were done on tumor tissue of 53 patients. The results were correlated with various prognostic factors of neuroblastoma. Aurora A mRNA and protein expression were identified in 9 of 9 neuroblastoma cell lines. Overexpression of Aurora A mRNA in neuroblastoma tumor tissue is associated with high risk (P = 0.019), high-stage (International Neuroblastoma Staging System III and IV) tumors (P = 0.007), unfavorable histology (P = 0.007), MYCN amplification (P = 0.017), disease relapse (P = 0.019), and decreased progression-free survival (P < 0.0001) but not correlated with the age at diagnosis (P = 0.877). Similarly, Aurora A protein expression also significantly correlated with high risk (P = 0.011), high stage (P = 0.0028), unfavorable histology (P = 0.0006), MYCN amplification (P = 0.0029), and disease relapse (P = 0.044). Small interfering RNA–mediated knockdown of the endogenous Aurora A gene causes a proliferation defect and enhances chemosensitivity in human neuroblastoma cell lines. In support of these observations, the Aurora A kinase inhibitor, MLN8054, markedly inhibited growth of cultured neuroblastoma cell lines through an apoptosis-dependent pathway. Overexpression of Aurora A is associated with disease progression in neuroblastoma. Inhibition of this kinase is a promising modality for neuroblastoma treatment. [Mol Cancer Ther 2009;8(8):2461–9]