HSP90调控MLKL在慢性粒细胞白血病耐药中的作用及机制研究

BCR-ABL tyrosine-kinase inhibitors are the main drugs used to treat chronic myelogenous leukemia (CML). However, CML in some patients have developed resistance. This results in unfavorable curative effect and the detailed mechanism is still to be clarified. Our previous work found that the high level of MLKL does relate to resistance of CML. In this study, we will detect the expression level and existential state of MLKL in CML by using flow cytometry and non-reducing polyacrylamide gel electrophoresis methods, then analyze the relationship between the high expression level of MLKL and the curative effect of targeted therapy to CML and its clinical significance. Meanwhile, we will attend to validate the molecular mechanism by which HSP90 modulates MLKL in activating inflammatory factor NLRP3. NLRP3,once been activated,can initiate the release of IL-1β which then results in resistance of CML. We will also screen yeast library to find new proteins which can regulate the high expression level of MLKL, and then study their functions in activating HSP90/MLKL/NLRP3 pathway and resistance of CML. In brief, this study is devoted to reveal the expression level, existential state and regulation rules of MLKL in CML, to illustrate the relationship between the functional status of MLKL and resistance of CML and its mechanism. The ultimate goal of research is to provide new insights into the drug resistance problem that BCR-ABL tyrosine-kinase inhibitors facing and to seek for new targets of CML treatment.

BCR-ABL酪氨酸激酶抑制剂是治疗慢性粒细胞白血病（CML）的主要药物，但部分患者会产生抗药性，制约着其疗效，其耐药机制仍未阐明。我们前期研究发现MLKL高表达与CML耐药相关。本研究拟以流式细胞术及非还原性凝胶电泳等技术，对CML中MLKL表达水平及存在状态进行检测，分析MLKL高表达与CML靶向治疗疗效的关系及其临床意义；同时，以分子生物学方法验证HSP90调控MLKL以激活NLRP3炎性因子并释放IL-1β进而导致CML耐药的分子调控机制；以酵母文库筛选调控MLKL高表达的新信号分子，研究其在激活HSP90/MLKL/NLRP3、介导CML耐药中的作用及其信号通路。本研究将揭示MLKL在CML中的表达水平、存在状态及调控规律，阐明MLKL功能状态与CML耐药的关系及其机理，为克服BCR-ABL酪氨酸激酶抑制剂的耐药提供新策略，为慢性粒细胞白血病的治疗提供新的靶点。

BCR-ABL酪氨酸激酶抑制剂是治疗慢性粒细胞白血病（CML）的主要药物，但部分患者会产生抗药性，制约着其疗效，其耐药机制仍未阐明。本研究旨在探讨HSP90是如何调控MLKL的？MLKL介导的坏死是否能够增强PD-L1的疗效以克服肿瘤耐药？通过本研究，我们阐明了HSP90及MLKL各关键位点对其相互作用的影响，以及由其导致的细胞生物学的改变。通过酵母双杂交技术，筛选鉴定了一个新的MLKL结合蛋白HIPK1。临床研究表明ZBP1、MLKL在黑色素肿瘤中低表达，并具有临床预后指示意义。考虑到肿瘤抗凋亡的耐药性，提示我们可通过激活肿瘤中ZBP1-RIPK3-MLKL坏死信号通路以克服其传统耐药。发现MLKL抑制剂Necrosulfonamide可以导致GSDMD的非经典切割（出现p40条带，而非经典的p30）。发现一个新的化合物PBA2可以抑制慢性粒白血病（一种影响血液及骨髓的恶性肿瘤），及克服伊马替尼耐药的慢性粒白血病。发现驱绦虫药物Niclosamide（氯硝柳胺，灭绦灵）可降低PD-L1表达，增加小鼠移植瘤组织中浸润T细胞数量及其活性，从而发挥抗肿瘤作用。发现丝裂霉素C可以增强非小细胞肺癌PD-L1的疗效。发现酪氨酸激酶抑制Olmutinib和Dacomitinib可以逆转肿瘤细胞的多药耐药。综上所述，激活MLKL介导的坏死有望使耐药的、对免疫治疗不敏感的“冷”肿瘤变为对免疫治疗敏感的“热”肿瘤，可极大的提高免疫检查点抑制剂的疗效，为耐药的“冷”肿瘤提供一种治疗策略。