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

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。

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.