低氧胶质瘤外泌体相关IL-6/MIR-155通路整体转运在肿瘤相关巨噬细胞自噬及其M2极化中的作用机制研究

As the most common malignant primary brain tumor, glioblastoma multiforme (GBM) responds poorly to conventional treatment. Although novel immunotherapies have been applied into glioma treatment, the prognosis of glioma patients is still very bad. Immunosuppressive microenvironment of glioma, which contains the tumor-associated macrophages (TAMs) plays important roles in the resistance to the treatments of this cancer. The regulating function of glioma-derived exosome on immune cells intrigued us to find new ideas in investigating the interactions between glioma cells and immune cells like TAMs. We have found that hypoxia induced Glioma-Derived Exosomes can significantly promote the expansion and M2 polarization of TAMs and that the integral-transfer of IL-6/MIR-155 pathway within hypoxia induced glioma-derived-exosomes plays the important roles during this process. We aim to provide new theoretical basis for modifying the current glioma immuno-therapy by interfering the TAMs autophagy and polarization.More importantly, we plan to interfere the critical TAMs autophagy and polarization associated molecules to provide new theoretical basis for modifying the current glioma immunotherapy.

人脑胶质瘤是中枢神经系统最常见的恶性肿瘤，传统疗法效果差。虽然多种免疫治疗策略相继问世，但在临床试验中鲜有成效，其微环境中浸润的肿瘤相关巨噬细胞（TAMs）等被认为是影响疗效的重要因素。胶质瘤相关外泌体调控途径为研究胶质瘤细胞与微环境中TAMs等免疫细胞间细胞通讯和极化调控提供了新思路。我们发现低氧诱导的胶质瘤外泌体能够显著上调TAMs的自噬水平，进而促进其M2极化，且低氧胶质瘤外泌体中整体转运的IL-6/IL-6R/MIR-155-3p通路在此过程中起关键作用。本课题拟通过表达谱芯片与生物信息学预测相结合，在体外和体内全面筛选并验证MIR-155-3p促TAMs自噬及极化的关键靶基因，阐明胶质瘤外泌体相关“IL-6/IL-6R/MIR-155-3p/自噬”通路整体转运假说，及其促进TAMs免疫抑制能力的分子机制，并针对关键节点设计干预方案，为改善现有胶质瘤免疫治疗策略提供新的理论依据。

人脑胶质瘤是中枢神经系统最常见的恶性肿瘤，传统疗法效果差。虽然多种免疫治疗策略相继问世，但在临床试验中鲜有成效，其微环境中浸润的肿瘤相关巨噬细胞（TAMs）等被认为是影响疗效的重要因素。胶质瘤相关外泌体调控途径为研究胶质瘤细胞与微环境中TAMs等免疫细胞间细胞通讯和极化调控提供了新思路。我们发现低氧诱导的胶质瘤外泌体能够显著上调TAMs的自噬水平，进而促进其M2极化，且低氧胶质瘤外泌体中整体转运的IL-6/IL-6R/miR-155-3p通路在此过程中起关键作用。本课题拟通过表达谱芯片与生物信息学预测相结合，在体外和体内全面筛选并验证miR-155-3p促TAMs自噬及极化的关键靶基因，阐明胶质瘤外泌体相关“IL-6/IL-6R/miR-155-3p/自噬”通路整体转运假说，及其促进TAMs免疫抑制能力的分子机制，并针对关键节点设计干预方案，为改善现有胶质瘤免疫治疗策略提供新的理论依据。. 我们首先沿标书主线证实，与常氧胶质瘤来源的外泌体(N-GDEs)相比，缺氧胶质瘤来源的外泌体(H-GDEs)显著促进巨噬细胞的自噬和M2极化。Western blot和qRT-PCR证实IL-6和miR-155-3p在H-GDEs中高表达。进一步实验表明IL-6和miR-155-3p可通过IL-6- pSTAT3 -miR-155-3p-自噬- pSTAT3正反馈回路诱导M2极化，促进胶质瘤进展。研究结果表明，IL-6和miR-155-3p可能是诊断胶质瘤的新型生物标志物，靶向自噬和STAT3通路的治疗可能有助于抗肿瘤免疫治疗。. 此外，我们还对GDE进行了miRNA测序分析，以鉴定介导巨噬细胞极化的其它主要miRNA，进而深入研究巨噬细胞中与miRNA相关的信号通路。通过对H-GDE进行miRNA测序分析，我们发现miR-1246表达量最高的miRNA。此外，miR-1246在GBM患者的脑脊液外泌体中高度富集，并在肿瘤切除后降低。进一步的研究发现了miR-1246通过靶向TERF2IP激活STAT3信号通路并抑制NF-κB信号通路来介导H-GDE诱导的M2巨噬细胞极化的新机制。该部分研究结果表明，胶质瘤患者脑脊液中的miR-1246可能也是GBM诊断的新生物标志物，靶向miR-1246的疗法能有助于抗肿瘤免疫治疗的发展。