Constitutive c-jun N-terminal kinase activity in acute myeloid leukemia derives from Flt3 and affects survival and proliferation
Constitutive c-jun N-terminal kinase activity in acute myeloid leukemia derives from Flt3 and affects survival and proliferation
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DOI：
10.1016/j.exphem.2006.05.019
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发表时间：
2006-10-01
影响因子：
2.6
通讯作者：
Boswell, H. Scott
中科院分区：
文献类型：
--
作者：
Hartman, Amy D.;Wilson-Weekes, Annique;Boswell, H. Scott
目的：c - jun N -末端激酶（JNK）在慢性髓系白血病中与酪氨酸激酶癌基因p210 BCR - ABL下游的增殖和存活有关。我们研究了在急性髓系白血病（AML）中JNK和FMS样酪氨酸激酶3（Flt3）之间是否存在类似关系。
方法：通过免疫沉淀法，在大多数检测的JNK阳性AML原始细胞中发现Flt3被激活，并被确定为JNK活性的潜在来源。通常，Flt3活性与基因位点的激活突变有关。然而，统计学关联表明JNK活性与Flt3表达水平相关，而非与突变相关。一个描述Flt3到JNK信号级联的衔接子网络被发现。
结果：通过对模型细胞系和原发性AML原始细胞裂解物进行共免疫沉淀试验，发现活性Flt3与p85磷酸肌醇 - 3（PI - 3）激酶相关，p85与cbl和CrkII/CrkL相关。在下拉试验中，JNK1从这些裂解物中与p85 - cbl - crkII/L共免疫沉淀，并与Crk蛋白的SH3结构域结合。通过小干扰RNA介导的Flt3或cbl（该信号组核心的衔接子）的缺失，抑制了底物c - jun上的JNK活性。在受Flt3信号影响的AML原始细胞中，用小分子抑制剂选择性抑制JNK，导致增殖抑制、细胞凋亡，并使细胞对蒽环类药物柔红霉素敏感。这些效应在JNK被抑制时发生，且无细胞外信号调节激酶或AKT通路的脱靶抑制，并且p38激酶激活（p53/p14arf肿瘤抑制通路中的一个效应因子）也得以维持或增强。
结论：JNK是AML中来自Flt3的一条可靠的信号通路，在具有活性Flt3信号（由Flt3突变或过表达引起）的相当一部分AML患者中，其增殖和存活功能是必需的。（c）2006国际实验血液学学会。由爱思唯尔公司出版。
Objective. c-jun N-terminal kinase (JNK) has been implicated in proliferation and survival downstream from the tyrosine kinase oncogene, p210 BCR-ABL, in chronic myeloid leukemia. We studied whether a similar relationship between JNK and FMS-like tyrosine kinase 3 (Flt3) describes acute myeloid leukemia (AML).Methods. By immunoprecipitation, Flt3 was found to be activated and identified as the potential origin of JNK activity in a heavy majority of JNK+ve AML blasts tested. Often, Flt3 activity is associated with activating mutation of the gene locus. However, statistical linkage tied JNK activity with Flt3 expression levels rather than with mutation. An adaptor network to describe the signal cascade Flt3-to-JNK was uncovered.Results. Active Flt3 was linked to p85 phosphoinositide-3 (PI-3) kinase, and p85 with chl and CrkII/CrkL by co-immunoprecipitaton assays from lysates of model cell lines and primary AML blasts. JNK1 co-immunoprecipitated from such lysates with p85-cbl-crkII/L and bound to Crk species SH3 domain in pull-down assay. siRNA-mediated depletion of Flt3 or of cbl, the adaptor at the nexus of this signaling group, inhibited JNK activity on substrate c-jun. Within ANIL blast cells influenced by Flt3 signaling, selective inhibition of JNK by a small molecule inhibitor, led to proliferative inhibition, apoptosis, and sensitizing cells to the anthracycline, daunorubicin. These effects occurred upon JNK inhibition without off-target inhibition of extracellular signal-regulated kinase or AKT pathways, and p38-kinase activation, an effector in the p53/p14 arf tumor suppressor pathway, was also maintained or augmented.Conclusion. JNK is a bonafide signaling pathway from Flt3 in ANIL whose function for proliferation and survival is required in a significant ANIL cohort with active Flt3 signaling, by mutation or overexpression of Flt3. (c) 2006 International Society for Experimental Hematology. Published by Elsevier Inc.