Abstract 4223: Combination therapy of BCR-ABL-positive B cell acute lymphoblastic leukemia by tyrosine kinase inhibitor dasatinib and c-Jun N-terminal kinase inhibition

Abstract

Abstract The Philadelphia chromosome (Ph), which leads to creation and expression of the fusion gene product BCR-ABL, underlines the pathogenesis of chronic myelogenous leukemia (CML) and a fraction of adult and pediatric acute B-lymphoblastic leukemia (B-ALL). The BCR-ABL tyrosine kinase inhibitors (TKIs) has shown a remarkable clinical activity in patients with CML, but their efficacy in treating Ph+ B-ALL is limited. Identifying additional therapeutic targets is important for the effective treatment of Ph+ B-ALL. In this study, we found that the c-Jun N-terminal kinase (JNK) signaling pathway is abnormally activated in both human and mouse BCR-ABL+ B-ALL cells, but the BCR-ABL TKI does not inhibit JNK activation in these cells. Inhibition of JNK, either by RNAi-mediated downregulation or by JNK inhibitors, could significantly reduce viability of Ph+ B-ALL cells. JNK inhibition by RNAi-mediated downregulation or JNK inhibitors also showed a synergistic effect with the BCR-ABL TKI, dasatinib, in killing Ph+ B-ALL cells in vitro. Furthermore, a potent JNK inhibitor, JNK-IN-8, in combination with dasatinib markedly improved the survival of mice with BCR-ABL induced B-ALL, as compared to the treatment with dasatinib alone. Our findings indicate that simultaneously targeting both BCR-ABL and JNK kinase might serve as a promising therapeutic strategy for Ph+ B-ALL. Citation Format: Xinhua Xiao, Bo Jiao, Ruibao Ren. Combination therapy of BCR-ABL-positive B cell acute lymphoblastic leukemia by tyrosine kinase inhibitor dasatinib and c-Jun N-terminal kinase inhibition [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4223.