BH3 mimetics, including the BCL2/BCLX_L/BCLw inhibitor navitoclax and MCL1 inhibitors S64315 and tapotoclax, have undergone clinical testing for a variety of neoplasms. Because of toxicities, including thrombocytopenia after BCLX_L inhibition as well as hematopoietic, hepatic and possible cardiac toxicities after MCL1 inhibition, there is substantial interest in finding agents that can safely sensitize neoplastic cells to these BH3 mimetics. Building on the observation that BH3 mimetic monotherapy induces AMP kinase (AMPK) activation in multiple acute leukemia cell lines, we report that the AMPK inhibitors (AMPKis) dorsomorphin and BAY-3827 sensitize these cells to navitoclax or MCL1 inhibitors. Cell fractionation and phosphoproteomic analyses suggest that sensitization by dorsomorphin involves dephosphorylation of the proapoptotic BCL2 family member BAD at Ser75 and Ser99, leading BAD to translocate to mitochondria and inhibit BCLX_L. Consistent with these results, BAD knockout or mutation to BAD S75E/S99E abolishes the sensitizing effects of dorsomorphin. Conversely, dorsomorphin synergizes with navitoclax or the MCL1 inhibitor S63845 to induce cell death in primary acute leukemia samples ex vivo and increases the antitumor effects of navitoclax or S63845 in several xenograft models in vivo with little or no increase in toxicity in normal tissues. These results suggest that AMPK inhibition can sensitize acute leukemia to multiple BH3 mimetics, potentially allowing administration of lower doses while inducing similar antineoplastic effects.

BH3 模拟物，包括 BCL2/BCLX _L /BCLw 抑制剂 navitoclax 和 MCL1 抑制剂 S64315 和 Tapotoclax，已针对多种肿瘤进行了临床测试。由于毒性，包括 BCLX _L抑制后的血小板减少症以及 MCL1 抑制后的造血、肝脏和可能的心脏毒性，人们对寻找能够安全地使肿瘤细胞对这些 BH3 模拟物敏感的药物产生了极大的兴趣。基于 BH3 模拟单一疗法在多种急性白血病细胞系中诱导 AMP 激酶 (AMPK) 激活的观察结果，我们报告 AMPK 抑制剂 (AMPKis) dorsomorphin 和 BAY-3827 使这些细胞对 navitoclax 或 MCL1 抑制剂敏感。细胞分级分离和磷酸蛋白质组学分析表明，dorsomorphin 致敏涉及促凋亡 BCL2 家族成员 BAD Ser75 和 Ser99 的去磷酸化，导致 BAD 易位至线粒体并抑制 BCLX _L 。与这些结果一致，BAD 敲除或 BAD S75E/S99E 突变消除了 Dorsomorphin 的致敏作用。相反，dorsomorphin 与 navitoclax 或 MCL1 抑制剂 S63845 协同作用，在离体原发性急性白血病样本中诱导细胞死亡，并在几种体内异种移植模型中增强 navitoclax 或 S63845 的抗肿瘤作用，而对正常组织的毒性几乎没有增加或没有增加。这些结果表明，AMPK 抑制可以使急性白血病对多种 BH3 模拟物敏感，可能允许以较低剂量给药，同时诱导类似的抗肿瘤作用。