The Apoptotic Mechanism of Action of the Sphingosine Kinase 1 Selective Inhibitor SKI-178 in Human Acute Myeloid Leukemia Cell Lines
The Apoptotic Mechanism of Action of the Sphingosine Kinase 1 Selective Inhibitor SKI-178 in Human Acute Myeloid Leukemia Cell Lines
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DOI：
10.1124/jpet.114.219659
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发表时间：
2015-03-01
影响因子：
3.5
通讯作者：
Yun, Jong K.
中科院分区：
文献类型：
--
作者：
Dick, Taryn E.;Hengst, Jeremy A.;Yun, Jong K.
我们先前开发了SKI-178(N‘-[(1E)-1-(3，4-二甲氧基苯基)ethylidene]-3-(4-methoxxyphenyl)-1H-pyrazole-5-carbohydrazide))作为一种新的鞘氨醇激酶-1(SphK1)选择性抑制剂，并在此试图确定SKI-178诱导细胞死亡的作用机制。以人急性髓系白血病(AML)细胞系为模型，我们提出了SKI-178通过固有的凋亡级联反应诱导长时间有丝分裂和随后的细胞死亡的证据。对SKI-178作用机制的进一步研究表明，c-Jun氨基末端激酶(JNK)和细胞周期蛋白依赖性蛋白激酶1(CDK1)是SKI-178诱导细胞凋亡的关键因素。在细胞周期同步化的人AML细胞系中，我们证明了SKI-178诱导凋亡需要进入有丝分裂，而SKI-178诱导的凋亡需要CDK1，而不是JNK。我们进一步证明，在SKI-178介导的长时间有丝分裂过程中，CDK1的持续激活导致了幸存的Bcl2家族成员Bcl2和Bclxl的同时磷酸化，以及Mcl-1的磷酸化和随后的降解。此外，多药耐药蛋白1和/或存活的Bcl2家族成员过表达介导的多药耐药并不影响AML细胞对SKI-178的敏感性。综上所述，这些发现突出了以SphK1为靶点的SKI-178作为治疗急性髓细胞白血病(包括多药耐药/复发急性髓细胞白血病亚型)的新型治疗剂的治疗潜力。
We previously developed SKI-178 (N'-[(1E)-1-(3,4-dimethoxyphenyl) ethylidene]-3-(4-methoxxyphenyl)-1H-pyrazole-5-carbohydrazide) as a novel sphingosine kinase-1 (SphK1) selective inhibitor and, herein, sought to determine the mechanism-of-action of SKI-178-induced cell death. Using human acute myeloid leukemia (AML) cell lines as a model, we present evidence that SKI-178 induces prolonged mitosis followed by apoptotic cell death through the intrinsic apoptotic cascade. Further examination of the mechanism of action of SKI-178 implicated c-Jun NH2-terminal kinase (JNK) and cyclin-dependent protein kinase 1 (CDK1) as critical factors required for SKI-178-induced apoptosis. In cell cycle synchronized human AML cell lines, we demonstrate that entry into mitosis is required for apoptotic induction by SKI-178 and that CDK1, not JNK, is required for SKI-178-induced apoptosis. We further demonstrate that the sustained activation of CDK1 during prolonged mitosis, mediated by SKI-178, leads to the simultaneous phosphorylation of the prosurvival Bcl-2 family members, Bcl-2 and Bcl-xl, as well as the phosphorylation and subsequent degradation of Mcl-1. Moreover, multidrug resistance mediated by multidrug-resistant protein1 and/or prosurvival Bcl-2 family member overexpression did not affect the sensitivity of AML cells to SKI-178. Taken together, these findings highlight the therapeutic potential of SKI-178 targeting SphK1 as a novel therapeutic agent for the treatment of AML, including multidrug-resistant/recurrent AML subtypes.