间充质干细胞、外泌体“双保险”负载miRNA协同TRAIL杀伤恶性脑胶质瘤的功能及机制研究

Malignant glioma is still one of the most lethal forms of brain tumor despite of the improvements in treatments. TRAIL (TNF-related apoptosis-inducing ligand) is a promising anticancer agent that can be potentially used as an alternative or complementary therapy because of its specific antitumor activity. TARIL resistance is one of the most serious problems for the clinical application. Mesenchymal stem cells (MSCs) are emerging as novel cell-based delivery agents even for malignant glioma because of its characteristics to go through the brain-blood barrier. In this project, the following specific aims are proposed: (1) To perform a genome-wide expression profiling of miRNAs in malignant glioma lines with the distinct sensitivity to TRAIL-induced apoptosis; (2) To find the miRNAs whose expression pattern is closely correlated with the sensitivity of malignant glioma cells to TRAIL induced cell death; (3) Using the gain and loss of function experiments to confirm the role of candidate miRNAs for TRAIL-induced apoptosis in glioma cells; (4) To investigate the mechanism of miRNAs for TRAIL-induced apoptosis in glioma cells; (5) To test the efficiency of MSCs-derived exosome to transfer TRAIL sensitivity associated miRNAs to glioma cells in vitro and in vivo; (6) To test the synergetically killing effect of TRAIL combined with MSCss and exosome “double insurance” loaded microRNAs in an orthotopic glioma model. Our study could identify miRNA-derived natural agonists for TRAIL-induced apoptosis, thus making it as a promising therapeutic candidate for TRAIL resistance in malignant glioma.

恶性脑胶质瘤是中枢神经系统高发恶性肿瘤，预后差，治疗手段有限，亟需探索新型治疗策略。肿瘤坏死因子诱导凋亡配体（TRAIL）是一种细胞内源凋亡诱导分子，对肿瘤细胞具有特异的促凋亡作用，但由于半衰期短和肿瘤细胞耐受的问题，尚无法达到满意疗效。近年来，间充质干细胞（MSCs）的肿瘤组织趋向性和外泌体（exosome）介导细胞间通讯已成为共识。本项目提出MSCs和exosome “双保险”负载miRNA协同TRAIL杀伤肿瘤细胞的设想。筛选具有TRAIL增敏作用的miRNA，并将其在表达TRAIL的MSCs中过表达，利用其肿瘤趋向性和血脑屏障自由通透的特点实现miRNA的病灶富集，再利用MSCs分泌的exosome将miRNA传送到肿瘤细胞内，从而实现miRNA增敏TRAIL协同杀伤肿瘤的作用，在细胞和动物水平评价该策略的特异性和高效性。该策略的建立对抑癌miRNA的肿瘤治疗学具有重要的指导意义。

本项目提出MSCs和exosome “双保险”负载miRNA协同TRAIL杀伤肿瘤细胞的设想。筛选并鉴定对TRAIL诱导凋亡增敏的miRNA，将其在表达TRAIL的MSCs中过表达，利用其肿瘤趋向性和血脑屏障自由通透的特点实现miRNA的病灶富集，再结合MSCs通过exosome介导的方式将miRNA送入肿瘤细胞内，实现肿瘤原位miRNA增敏TRAIL协同杀伤肿瘤的作用。在本项目的资助下，我们鉴定出包括miR-7、miR-124、miR-205和miR-29/miR-30等在内的多个miRNA分子通过靶向抗凋亡分子XIAP、溶血磷脂酰胆碱酰基转移酶LPCAT1和赖氨酰氧化酶LOXL4等分子调控TRAIL诱导胶质瘤细胞凋亡敏感性、肿瘤生长和肿瘤免疫微环境重塑的作用。相关研究已发表Nucleic Acids Research(2017，论文发表于项目申请期间)，Theranostics(2020，封面文章)和Biochem Biophys Res Commun.(2020)等杂志。在本项目的资助下我们开展了新领域的拓展研究：证明FoxM1-STMN1转录信号轴异常高活性是促进多种肿瘤生长的关键分子事件(Signal Transduct Target Ther. 2021)；证明髓系细胞m6A修饰动态变化是调控肿瘤免疫微环境的重要表观遗传学事件(Nat Commun. 2021)。我们还围绕肿瘤相关非编码RNA的功能机制、肿瘤免疫、肿瘤代谢和肿瘤神经互作等领域调研文献，撰写英文综述5篇。在本项目资助下，共招收博士研究生4人(在读)、硕士研究生1人(毕业2021)、博士后2人(在站)。1人获国家博士生奖学金(2021)，1人获校级优秀博士生课题资助(2021)。在本项目的资助下共发表论文10篇，其中IF大于10的论文5篇，IF大于5的论文3篇。