Alisertib, an Aurora kinase A inhibitor, induces apoptosis and autophagy but inhibits epithelial to mesenchymal transition in human epithelial ovarian cancer cells

Yong-Hui Ding,^1,2 Zhi-Wei Zhou,^2,3 Chun-Fang Ha,¹ Xue-Yu Zhang,¹ Shu-Ting Pan,⁴ Zhi-Xu He,³ Jeffrey L Edelman,² Dong Wang,⁵ Yin-Xue Yang,⁶ Xueji Zhang,⁷ Wei Duan,⁸ Tianxin Yang,⁹ Jia-Xuan Qiu,⁴ Shu-Feng Zhou<sup>2,3

1</sup>Department of Gynecology, General Hospital of Ningxia Medical University, Yinchuan, People’s Republic of China; ²Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA ; ³Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, ⁴Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, ⁵Cancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing, ⁶Department of Colorectal Surgery, General Hospital of Ningxia Medical University, Yinchuan, ⁷Research Center for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing, People’s Republic of China; ⁸School of Medicine, Deakin University, Waurn Ponds, Australia; ⁹Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USA

Abstract: Ovarian cancer is a leading killer of women, and no cure for advanced ovarian cancer is available. Alisertib (ALS), a selective Aurora kinase A (AURKA) inhibitor, has shown potent anticancer effects, and is under clinical investigation for the treatment of advanced solid tumor and hematologic malignancies. However, the role of ALS in the treatment of ovarian cancer remains unclear. This study investigated the effects of ALS on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition (EMT), and the underlying mechanisms in human epithelial ovarian cancer SKOV3 and OVCAR4 cells. Our docking study showed that ALS, MLN8054, and VX-680 preferentially bound to AURKA over AURKB via hydrogen bond formation, charge interaction, and π-π stacking. ALS had potent growth-inhibitory, proapoptotic, proautophagic, and EMT-inhibitory effects on SKOV3 and OVCAR4 cells. ALS arrested SKOV3 and OVCAR4 cells in G₂/M phase and induced mitochondria-mediated apoptosis and autophagy in both SKOV3 and OVCAR4 cell lines in a concentration-dependent manner. ALS suppressed phosphatidylinositol 3-kinase/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways but activated 5′-AMP-dependent kinase, as indicated by their altered phosphorylation, contributing to the proautophagic activity of ALS. Modulation of autophagy altered basal and ALS-induced apoptosis in SKOV3 and OVCAR4 cells. Further, ALS suppressed the EMT-like phenotype in both cell lines by restoring the balance between E-cadherin and N-cadherin. ALS downregulated sirtuin 1 and pre-B cell colony enhancing factor (PBEF/visfatin) expression levels and inhibited phosphorylation of AURKA in both cell lines. These findings indicate that ALS blocks the cell cycle by G2/M phase arrest and promotes cellular apoptosis and autophagy, but inhibits EMT via phosphatidylinositol 3-kinase/Akt/mTOR-mediated and sirtuin 1-mediated pathways in human epithelial ovarian cancer cells. Further studies are warranted to validate the efficacy and safety of ALS in the treatment of ovarian cancer.

Keywords: alisertib, Aurora kinase A, epithelial ovarian cancer, cell cycle, apoptosis, autophagy, epithelial to mesenchymal transition, sirtuin 1