Abstract 4158: Targeting the imatinib-resistant BCR-ABL T315I mutation in chronic myeloid leukemia through a novel BCR-ABL inhibitor

Abstract

Abstract Chronic Myeloid Leukemia (CML), a hematological malignancy, is largely caused by the Philadelphia (Ph) chromosome carrying the Break point Cluster Region-Abelson (BCR-ABL) oncogene. Imatinib is a BCR-ABL-targeted therapy and considered the standard of care in CML management. Resistance to imatinib therapy often develops because of mutations in the BCR-ABL kinase domain. In this study, we evaluated PBA2, a novel BCR-ABL inhibitor, for its anti-cancer activity against BCR-ABL expressing BaF3 cells. PBA2 shows potent activity against wild-type and T315I mutated BaF3 cells as compared with imatinib. PBA2 inhibited the phosphorylation of BCR-ABL and its downstream signaling in BaF3/WT and BaF3/T315I cells. PBA2 inhibited the mRNA expression of BCR-ABL in BaF3/WT and BaF3/T315I cells. Mechanistically, PBA2 increased the cell population in sub G1 phase of the cell cycle, induced apoptosis and elevated ROS production in both BaF3/WT and BaF3/T315I cells. Taken together, our results indicate that PBA2 exhibits anti-proliferative effects and inhibits the imatinib-resistant T315I BCR-ABL mutation. PBA2 may be a novel drug candidate for overcoming the resistance to imatinib in CML patients. Note: This abstract was not presented at the meeting. Citation Format: Pranav Gupta, Rishil Kathawala, Liuya Wei, Fang Wang, XiaoKun Wang, Brian J. Druker, Li-Wu FU, Zhe-Sheng Chen. Targeting the imatinib-resistant BCR-ABL T315I mutation in chronic myeloid leukemia through a novel BCR-ABL inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4158. doi:10.1158/1538-7445.AM2017-4158