HEXB介导的胶质瘤细胞与M2型肿瘤相关巨噬细胞间的相互调节与作用机制研究

Macrophage is one of the most abundant non-tumor cells within glioma microenvironment, which facilitates malignancy progression and treatment resistance. Here, we conducted an integrative analysis to screen out the key oncogenic factor that plays a synergistic role in both glioma cell and macrophage. We found that HEXB, as a subunit of secreted hexosaminidase, plays an important role in glioma progression and the process of macrophage chemotaxis and polarization. Based on our previous findings, we proposed “The crosstalk and mechanism of HEXB mediated oncogenic feedback between glioma cells and M2-polarized tumor associated macrophages” in this project. Firstly, the relationship between HEXB and the characteristics of clinical phenotype and microenvironment components will be fully profiled. Secondly, gene intervention, molecular inhibitor and recombinant protein will be performed to affect HEXB expression in both in vitro co-cultured model and in vivo xenograft model. The role of HEXB in regulating the phenotype of glioma cell, macrophage and their interaction will be fully studied. Thirdly, DNA methylation Inhibitor and luciferase reporter system will be used to clarify the upstream regulation of IDH mutation associated CpG methylation on HEXB promoter. Fourthly, CoIP, GST-Pulldown and mass spectrometry will be performed to explore the effect of HEXB on activating Integrin downstream network. Finally, the synergistic effect of targeting HEXB combined with temozolomide and PD-1 mAb will be examined in vitro and in vivo. This project will reveal a HEXB-mediated oncogenic feedback between glioma cell and macrophage, and identify a novel target with multiple therapeutic potentials.

课题组整合分析胶质瘤与巨噬细胞数据，以期鉴定到在二者之中发挥协同作用的关键促癌因子。我们发现HEXB作为一种分泌蛋白，同胶质瘤恶性表现以及巨噬细胞趋化极化过程密切相关，故提出“HEXB介导的胶质瘤细胞与M2型肿瘤相关巨噬细胞间的相互调节与作用机制研究”。项目在解析HEXB临床价值与微环境代表性的基础上，利用基因干预、小分子抑制剂及重组蛋白，在体外共培养与小鼠模型中，研究HEXB在维持胶质瘤细胞、巨噬细胞表型以及二者互作过程中的作用；借助报告基因、甲基化抑制等手段，明确IDH突变通过甲基化对HEXB转录的上游调节作用，并运用CoIP、GST-Pulldown、质谱等方法，研究HEXB活化Integrin下游信号网络的工作机制；探索干预HEXB联合替莫唑胺化疗与PD-1单抗的协同治疗效应。本项目可揭示HEXB介导的胶质瘤细胞-巨噬细胞正反馈促癌环路，为确立具有多重作用的治疗靶点提供理论支撑。

近期研究表明胶质瘤发生发展的过程即为胶质瘤细胞与其微环境的交互改造过程，两者共同构成了复杂的“命运共同体”。申请人前期证实肿瘤相关巨噬细胞（TAMs）是胶质瘤微环境中含量最为丰富的免疫细胞并参与胶质瘤免疫抑制微环境的重塑过程。申请人从胶质瘤与微环境结成“命运共同体” 的新视角，对胶质瘤及巨噬细胞数据进行联合分析，鉴定到多种在胶质瘤及巨噬细胞中发挥协同恶性作用的关键节点。本课题基本完成预定目标，明确了HEXB介导的“胶质瘤细胞-M2型肿瘤相关巨噬细胞”的正反馈环路，发现了趋化素通过CMKLR1依赖的自分泌和旁分泌调节网络增强胶质母细胞瘤间充质特征，提出了ARPC1B在胶质母细胞瘤恶性进展中以及胶质瘤细胞与巨噬细胞之间相互调节网络中的具有关键性作用。本研究围绕免疫微环境再胶质瘤恶性进展中的重要作用，以TAMs为切入点，深入挖掘调控胶质瘤与微环境结成“命运共同体”的关键枢纽，从而完善肿瘤免疫抑制微环境重塑理论，为提高肿瘤免疫诊疗效果提供有益参考。