Mutations in the tyrosine kinase domain of FLT3 define a new molecular mechanism of acquired drug resistance to PTK inhibitors in FLT3-ITD-transformed hematopoietic cells
Mutations in the tyrosine kinase domain of FLT3 define a new molecular mechanism of acquired drug resistance to PTK inhibitors in FLT3-ITD-transformed hematopoietic cells
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DOI：
10.1182/blood-2003-05-1653
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发表时间：
2004-03-15
期刊：
影响因子：
20.3
通讯作者：
Spiekermann, K
中科院分区：
文献类型：
--
作者：
Bagrintseva, K;Schwab, R;Spiekermann, K
近膜结构域（FLT3-长度突变，FLT3- lm）和FLT3蛋白酪氨酸激酶结构域（FLT3-TKD）的激活突变代表了急性髓性白血病（AML）中最常见的遗传改变，并确定了蛋白酪氨酸激酶（PTK）抑制剂治疗干预的分子靶点。我们可以证明，在FLT3转化的细胞系中，D835位置的不同激活FLT3- tkd突变介导了对FLT3 PTK抑制剂的原发性耐药。在FLT3 PTK抑制剂SU5614浓度增加的情况下，我们产生了Ba/F3 FLT3-内部串联重复（ITD）细胞系（Ba/F3 FLT3-ITD- r1 - r4），其对SU5614的IC50（抑制50%的浓度）比亲本ITD细胞高7- 26倍。对ITD- r1 -4细胞的分子表征表明，在SU5614的选择过程中，在ITD背景下获得了特异性的TKD突变（D835N和Y842H）。在Ba/F3细胞中引入这些双ITD-TKD，而不是单一的D835N或Y842H FLT3突变体，恢复了FLT3抑制剂抗性表型。我们的数据表明，FLT3 PTK结构域的预先存在或获得性突变可诱导对FLT3 PTK抑制剂的体外耐药。这些发现为AML患者FLT3 PTK抑制剂的临床耐药评估提供了分子基础。(C) 2004年由美国血液病学会出版。
Activating mutations in the juxtamembrane domain (FLT3-length mutations, FLT3-LM) and in the protein tyrosine kinase domain (TKD) of FLT3 (FLT3-TKD) represent the most frequent genetic alterations in acute myeloid leukemia (AML) and define a molecular target for therapeutic interventions by protein tyrosine kinase (PTK) inhibitors. We could show that distinct activating FLT3-TKD mutations at position D835 mediate primary resistance to FLT3 PTK inhibitors in FLT3-transformed cell lines. In the presence of increasing concentrations of the FLT3 PTK inhibitor SU5614, we generated inhibitor resistant Ba/F3 FLT3-internal tandem duplication (ITD) cell lines (Ba/F3 FLT3-ITD-R1-R4) that were characterized by a 7- to 26-fold higher IC50 (concentration that inhibits 50%) to SU5614 compared with the parental ITD cells. The molecular characterization of ITD-R1-4 cells demonstrated that specific TKD mutations (D835N and Y842H) on the ITD background were acquired during selection with SU5614. Introduction of these dual ITD-TKD, but not single D835N or Y842H FLT3 mutants, in Ba/F3 cells restored the FLT3 inhibitor resistant phenotype. Our data show that preexisting or acquired mutations in the PTK domain of FLT3 can induce drug resistance to FLT3 PTK inhibitors in vitro. These findings provide a molecular basis for the evaluation of clinical resistance to FLT3 PTK inhibitors in patients with AML. (C) 2004 by The American Society of Hematology.