突变体FMS样酪氨酸激酶-3的选择性降解需要对热激蛋白的BIM依赖性消耗
Selective degradation of mutant FMS-like tyrosine kinase-3 requires BIM-dependent depletion of heat shock proteins
影响因子:13.40000
分区:医学1区 Top / 血液学1区 肿瘤学2区
发表日期:2024 Dec
作者:
Melisa Halilovic, Mohamed Abdelsalam, Joanna Zabkiewicz, Michelle Lazenby, Caroline Alvares, Matthias Schmidt, Walburgis Brenner, Sara Najafi, Ina Oehme, Christoph Hieber, Yanira Zeyn, Matthias Bros, Wolfgang Sippl, Oliver H Krämer
摘要
FMS样酪氨酸激酶-3（FLT3-ITD）中的内部串联重复是急性髓样白血病（AML）的常见突变。诱导突变的FLT3蛋白酶体降解作为创新的药理学方法的蛋白酶体降解的蛋白水解靶向嵌合体（Protac）。控制靶向蛋白水解的分子机制超出了泛素 - 蛋白酶体系，是未定义的，Protac是唯一已知的FLT3降解器。我们报告说，基于von-Hippel-Lindau泛素 - 基因 - 岩石酶基于FLT3 Protac MA49（Melotinib-49）和FLT3疏水标记分子MA50（Halotinib-50）减少了内质网相关的，与内质网的flt3-Itd，但备用FLT3。 MA49和MA50的纳摩尔剂量诱导人类白血病细胞系和原代AML爆炸的凋亡（p <0.05-0.0001），但不能诱导原发性造血干细胞和分化的免疫细胞，FLT3野生型细胞，野生型细胞，视网膜细胞和C-kit依赖性细胞。 MA49对FLT3-ITD阳性白血病细胞的体内活性在Danio Rerio模型中得到了验证。降解者诱导的FLT3-ITD丢失涉及促凋亡的仅BH3蛋白BIM和先前未鉴定的脱脂剂诱导的蛋白质折叠伴侣的消耗。 Hsp90和Hsp110的表达水平与AML患者的存活率降低（P <0.1）和HSP90，HSP110和BIM相关，与原代AML细胞中FLT3的表达相关（P <0.01）。 HSP90抑制了降解器诱导的FLT3-ITD消除，从而建立了机械定义的进料回路。
Abstract
Internal tandem duplications in the FMS-like tyrosine kinase-3 (FLT3-ITD) are common mutations in acute myeloid leukemia (AML). Proteolysis-targeting chimeras (PROTACs) that induce proteasomal degradation of mutated FLT3 emerge as innovative pharmacological approach. Molecular mechanisms that control targeted proteolysis beyond the ubiquitin-proteasome-system are undefined and PROTACs are the only known type of FLT3 degraders. We report that the von-Hippel-Lindau ubiquitin-ligase based FLT3 PROTAC MA49 (melotinib-49) and the FLT3 hydrophobic tagging molecule MA50 (halotinib-50) reduce endoplasmic reticulum-associated, oncogenic FLT3-ITD but spare FLT3. Nanomolar doses of MA49 and MA50 induce apoptosis of human leukemic cell lines and primary AML blasts with FLT3-ITD (p < 0.05-0.0001), but not of primary hematopoietic stem cells and differentiated immune cells, FLT3 wild-type cells, retinal cells, and c-KIT-dependent cells. In vivo activity of MA49 against FLT3-ITD-positive leukemia cells is verified in a Danio rerio model. The degrader-induced loss of FLT3-ITD involves the pro-apoptotic BH3-only protein BIM and a previously unidentified degrader-induced depletion of protein-folding chaperones. The expression levels of HSP90 and HSP110 correlate with reduced AML patient survival (p < 0.1) and HSP90, HSP110, and BIM are linked to the expression of FLT3 in primary AML cells (p < 0.01). HSP90 suppresses degrader-induced FLT3-ITD elimination and thereby establishes a mechanistically defined feed-back circuit.