Abstract 3032: A novel compound ARN-3236 inhibits SIK2 and sensitizes ovarian cancer to paclitaxel

Abstract

Abstract Ovarian carcinomas account for 4% of total cancers in women in the United States. Improved outcomes might be attained if sensitivity to primary chemotherapy were enhanced. A recent study discovered that the salt inducible kinase 2 (SIK2) plays a key role in the initiation of mitosis and regulates paclitaxel sensitivity. Here we show that SIK2 is overexpressed in 30% ovarian cancer specimens, associated with a poor prognosis. ARN-3236, a selective, highly potent small molecule SIK2 inhibitor with function similar to SIK2 siRNA, blocks cell proliferation in a panel of ovarian cancer cell lines, where the IC50 of ARN-3236 was inversely correlated with endogenous SIK2 expression. ARN-3236 also enhanced response to paclitaxel in ovarian cancer cells (OC316, SKOv3, A2780, HEY, ES2 and UPN251). Similar to the function of SIK2 siRNA, ARN-3236 effectively inhibits AKT phosphorylation at Ser473 and Tyr308, as well as the expression of the downstream effector survivin. ARN-3236 uncouples the centrosome from the nucleus in interphase, and blocks centrosome separation in mitosis, resulting in the accumulation of cells in prometaphase. In addition, ARN-3236 enhances tumor growth inhibition of paclitaxel in ovarian cancer xenograft models. Thus, functional inhibition of SIK2 with ARN-3236 had the same effects on ovarian cancer cell function as knockdown of SIK2 with siRNA. ARN-3236 deserves further study as a SIK2 inhibitor that significantly improves the sensitivity to paclitaxel for treatment of human ovarian cancer cells and xenografts. Citation Format: Jinhua Zhou, Albandri Alfredi, Shu Zhang, Janice M. Santiago-O’Farrill, Ahmed A. Ahmed, Hailing Yang, Weiqun Mao, Yan Wang, Hariprasad Vankayalapati, Zhen Lu, Robert C. Bast Jr. A novel compound ARN-3236 inhibits SIK2 and sensitizes ovarian cancer to paclitaxel. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3032.