Alvarez-Calderon Francesca, Gregory Mark A, Pham-Danis Catherine, DeRyckere Deborah, Stevens Brett M, Zaberezhnyy Vadym, Hill Amanda A, Gemta Lelisa, Kumar Amit, Kumar Vijay, Wempe Michael F, Pollyea Daniel A, Jordan Craig T, Serkova Natalie J, Graham Douglas K, DeGregori James
Integrated Department of Immunology, University of Colorado Anschutz Medical Campus, Aurora, Colorado. Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado. School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado. Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
Clin Cancer Res. 2015 Mar 15;21(6):1360-72. doi: 10.1158/1078-0432.CCR-14-2146. Epub 2014 Dec 29.
Although tyrosine kinase inhibitors (TKI) can be effective therapies for leukemia, they fail to fully eliminate leukemic cells and achieve durable remissions for many patients with advanced BCR-ABL(+) leukemias or acute myelogenous leukemia (AML). Through a large-scale synthetic lethal RNAi screen, we identified pyruvate dehydrogenase, the limiting enzyme for pyruvate entry into the mitochondrial tricarboxylic acid cycle, as critical for the survival of chronic myelogenous leukemia (CML) cells upon BCR-ABL inhibition. Here, we examined the role of mitochondrial metabolism in the survival of Ph(+) leukemia and AML upon TK inhibition.
Ph(+) cancer cell lines, AML cell lines, leukemia xenografts, cord blood, and patient samples were examined.
We showed that the mitochondrial ATP-synthase inhibitor oligomycin-A greatly sensitized leukemia cells to TKI in vitro. Surprisingly, oligomycin-A sensitized leukemia cells to BCR-ABL inhibition at concentrations of 100- to 1,000-fold below those required for inhibition of respiration. Oligomycin-A treatment rapidly led to mitochondrial membrane depolarization and reduced ATP levels, and promoted superoxide production and leukemia cell apoptosis when combined with TKI. Importantly, oligomycin-A enhanced elimination of BCR-ABL(+) leukemia cells by TKI in a mouse model and in primary blast crisis CML samples. Moreover, oligomycin-A also greatly potentiated the elimination of FLT3-dependent AML cells when combined with an FLT3 TKI, both in vitro and in vivo.
TKI therapy in leukemia cells creates a novel metabolic state that is highly sensitive to particular mitochondrial perturbations. Targeting mitochondrial metabolism as an adjuvant therapy could therefore improve therapeutic responses to TKI for patients with BCR-ABL(+) and FLT3(ITD) leukemias.
尽管酪氨酸激酶抑制剂（TKI）可有效治疗白血病，但对于许多晚期BCR-ABL（+）白血病或急性髓性白血病（AML）患者，它们无法完全清除白血病细胞并实现持久缓解。通过大规模合成致死性RNA干扰筛选，我们确定丙酮酸脱氢酶（丙酮酸进入线粒体三羧酸循环的限速酶）对于慢性髓性白血病（CML）细胞在BCR-ABL抑制后存活至关重要。在此，我们研究了线粒体代谢在TK抑制后Ph（+）白血病和AML存活中的作用。
检测了Ph（+）癌细胞系、AML细胞系、白血病异种移植瘤、脐血和患者样本。
我们发现线粒体ATP合酶抑制剂寡霉素A在体外极大地增强了白血病细胞对TKI的敏感性。令人惊讶的是，寡霉素A在低于抑制呼吸所需浓度100至1000倍的情况下，使白血病细胞对BCR-ABL抑制敏感。寡霉素A处理迅速导致线粒体膜去极化并降低ATP水平，并在与TKI联合使用时促进超氧化物产生和白血病细胞凋亡。重要的是，在小鼠模型和原发性急变期CML样本中，寡霉素A增强了TKI对BCR-ABL（+）白血病细胞的清除作用。此外，在体外和体内，寡霉素A与FLT3 TKI联合使用时，也极大地增强了对FLT3依赖性AML细胞的清除作用。
白血病细胞中的TKI治疗会产生一种对特定线粒体扰动高度敏感的新代谢状态。因此，将线粒体代谢作为辅助治疗靶点可改善BCR-ABL（+）和FLT3（ITD）白血病患者对TKI的治疗反应。
