Inhibition of Bcl-2 Synergistically Enhances the Antileukemic Activity of Midostaurin and Gilteritinib in Preclinical Models of FLT3-Mutated Acute Myeloid Leukemia
Inhibition of Bcl-2 Synergistically Enhances the Antileukemic Activity of Midostaurin and Gilteritinib in Preclinical Models of FLT3-Mutated Acute Myeloid Leukemia
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DOI：
10.1158/1078-0432.ccr-19-0832
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发表时间：
2019-11-15
影响因子：
11.5
通讯作者：
Ge, Yubin
中科院分区：
文献类型：
--
作者：
Ma, Jun;Zhao, Shoujing;Ge, Yubin
目的：探讨FLT3抑制剂米多舒林或吉特替尼联合Bcl-2抑制剂venetoclax治疗FLT3-内串联重复（ITD）型急性髓系白血病（AML）的疗效及其分子机制。实验设计：采用FLT3-ITD细胞系和原发患者样本，采用Annexin V-FITC/碘化丙啶染色和流式细胞术分析，定量测定midosvin或gilteritinib单独或联合venetoclax诱导的细胞死亡。Western blot分析JAK/STAT、MAPK/ERK、PI3K/AKT通路成员以及Bcl-2蛋白家族成员的蛋白表达水平变化。采用mv4 -11来源的异种移植小鼠模型，评估吉特替尼与维托克拉克斯联合使用的体内疗效。Mcl-1的慢病毒过表达被用来证实其在midoshuin或gilteritinib联合venetoclax诱导的细胞死亡中的作用。RT-PCR检测Mcl-1转录物水平的变化。结果：米多舒林或吉替尼联合venetoclax可有效协同诱导FLT3-ITD AML细胞系和原发患者样本的细胞凋亡。FLT3抑制剂诱导Mcl-1下调，增强venetoclax活性。venetoclax可诱导磷酸化的erk表达，但venetoclax与midoshuin或gilteritinib联合使用可消除磷酸化的erk表达。midoshuin或gilteritinib同时下调Mcl-1， venetoclax同时抑制Bcl-2，导致“游离”Bim，从而协同诱导细胞凋亡。体内实验结果表明，吉特替尼与venetoclax合用具有治疗潜力。结论：venetoclax对Bcl-2的抑制可协同提高米多舒林和吉特替尼治疗flt3突变AML的疗效。
Purpose: To investigate the efficacy of the combination of the FLT3 inhibitors midostaurin or gilteritinib with the Bcl-2 inhibitor venetoclax in FLT3-internal tandem duplication (ITD) acute myeloid leukemia (AML) and the underlying molecular mechanism.Experimental Design: Using both FLT3-ITD cell lines and primary patient samples, Annexin V-FITC/propidium iodide staining and flow cytometry analysis were used to quantify cell death induced by midostaurin or gilteritinib, alone or in combination with venetoclax. Western blot analysis was performed to assess changes in protein expression levels of members of the JAK/STAT, MAPK/ERK, and PI3K/AKT pathways, and members of the Bcl-2 family of proteins. The MV4-11-derived xenograft mouse model was used to assess in vivo efficacy of the combination of gilteritinib and venetoclax. Lentiviral overexpression of Mcl-1 was used to confirm its role in cell death induced by midostaurin or gilteritinib with venetoclax. Changes of Mcl-1 transcript levels were assessed by RT-PCR.Results: The combination of midostaurin or gilteritinib with venetoclax potently and synergistically induces apoptosis in FLT3-ITD AML cell lines and primary patient samples. The FLT3 inhibitors induced downregulation of Mcl-1, enhancing venetoclax activity. Phosphorylated-ERK expression is induced by venetoclax but abolished by the combination of venetoclax with midostaurin or gilteritinib. Simultaneous downregulation of Mcl-1 by midostaurin or gilteritinib and inhibition of Bcl-2 by venetoclax results in "free" Bim, leading to synergistic induction of apoptosis. In vivo results show that gilteritinib in combination with venetoclax has therapeutic potential.Conclusions: Inhibition of Bcl-2 via venetoclax synergistically enhances the efficacy of midostaurin and gilteritinib in FLT3-mutated AML.