LAUSR

T315I mutation of Bcr-Abl in chronic myeloid leukemia (CML) leads to therapeutic resistance. It is known that Bcr-Abl transformation causes ROS-induced DNA damage, which can be exploited for anti-nucleotide treatment. We developed a small compound, JMF4073, which inhibits pyrimidylate kinases. Intriguingly, treatment of JMF4073 selectively eliminated WT-, but not T315I-, Bcr-Abl-transformed cells. We found that the higher level of cellular glutathione(GSH) in T315I-Bcr-Abl cells confers replication fork progression and sustains dTTP pool, leading to JMF4073 insusceptibility. Blocking mitochondrial pyruvate carrier (MPC) by UK-5099 reduced GSH and induced DNA replication stress in T315I-Bcr-Abl cells, thus increasing JMF4073 sensitivity in vitro and in vivo. We also observed the increases in glutamine flux to GSH production in T315I-Bcr-Abl cells, and reductive carboxylation of glutamate metabolism, together with mitochondrial dysfunction. The proteomic assay revealed the deficiencies in respiration complex I, II, and IV proteins in T315I-Bcr-Abl cells. Most interestingly, calcineurin inhibition remarkably elevated mitochondrial oxidative stress to cause cytotoxicity specifically in T315I-Bcr-Abl cells. Our results demonstrate the metabolic shift by T315I mutation of Bcr-Abl CML and provide the therapeutic options by co-targeting mitochondria and pyrimidylate kinases. Citation Format: Chang-Yu Huang, Yin-Hsuan Chung, Sheng-Yang Wu, Hsin-Yang Wang, Chih-Yu Lin, Tsung-Jung Yang, Jim-Ming Fang, Yu-Ju Chen, Chun-Mei Hu, Zee-Fen Chang. Co-targeting mitochondria and nucleotide metabolism in T315I-BCR-ABL myeloid leukemia for therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1602.