Abstract 113: Effect of targeting Aurora kinase A in human oral squamous cell carcinoma cells

Abstract

Abstract Oncogene addiction has provided therapeutic opportunities in many human malignancies, but molecular targeted therapy for oral squamous cell carcinoma (OSCC) is not available. In this study, we identified an appropriate molecule for treatment of patients with OSCC. We determined the gene expression profiles in 10 human OSCC cell lines and a non-neoplastic keratinocyte cell line by microarray analysis, and then identified Aurora kinase A (AURKA) as a cancer-related gene which was commonly overexpressed in OSCC cells. We also confirmed the overexpression of AURKA mRNA in OSCC tissues and compared to normal oral mucosa tissues by quantitative RT-PCR. AURKA plays an essential role in centrosome duplication, mitoic entry, and spindle assembly. Overexpression of AURKA in human malignancies is associated with gene amplification, genetic instability, poor histological differentiation, and poor prognosis. To determine if the AURKA is a plausible therapeutic target, we investigated the effect of small interfering RNAs specific for AURKA(siAURKA) and an AURKA selective inhibitor MLN8237 on the growth of human OSCC cells in vitro and in vivo. Knockdown of AURKA by RNA interference (RNAi) markedly inhibited the growth of OSCC cells and observed the change of colony formation and cell size looked like cell cycle arrest. We examined the RNAi effect of siAURKA in OSCC cells by Western blotting. Compared with non-target siRNA, the protein expression level of AURKA was almost completely suppressed. MLN8237 also reduced the cell growth, but showed relatively resistant to cells expressing AURKA at high levels. Transfection of siAURKA inhibited the growth of OSCC cells more potent than treatment with MLN8237 in vitro. Furthermore, we confirmed the effect of siAURKA and MLN8237 on the growth of human OSCC tumors which had been subcutaneously xenografted in athymic nude mice. Atelocollagen-siAURKA (8 nmol) complexes were injected into the tail vein every 3 days and MLN8237 (30 mg/kg) were received orally for 14 consecutive days. We found that siAURKA and MLN8237 significantly reduced the size of subcutaneously xenografted OSSC tumors. Interestingly, the combination of siAURKA and MLN8237 induced remarkable anti-tumor activity compared with single agent groups. These results suggest that AURKA functions as a critical gene for supporting the growth of human OSCC cells and targeting AURKA may be a useful therapeutic strategy for OSCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 113. doi:1538-7445.AM2012-113