细胞自主性未折叠蛋白反应调控癌基因/重编程因子驱动下胶质瘤细胞可塑性研究

Glioma is one of the most difficult-to-cure cancers. Cell plasticity acquisition drived by oncogenes/reprogramming factors, that is, dedifferentiation into glioma initiating cells and maintenance of the progenitor properties, is the source of glioma carcinogenesis and tumor progression. Cell autonomous unfolded protein response (UPR) activation is a necessary behaviour upon the cell transformation drived by oncogenes/reprogramming factors, but the mechanism of which is unknown. Based on the previous study, this project for the first time raises that cell autonomous UPR has an important role on regulation of cell plasticity drived by oncogenes/reprogramming factors. We will detect the cell autonomous UPR activation in both glioma initiating cells and oncogenes/reprogramming factors transformed glioma cells, investigate the alteration of cell plasticity properties such as undifferentiation state maintenance and tumor formation capacity after inhibition of UPR molecules of interest, acquire the direct target cell-plasticity-related genes regulated by interested UPR molecules and investigate the impact of interested UPR molecules on transcription activities of oncogenes/reprogramming factors by use of Chip-on-Chip analysis, explore and validate the molecular mechanism of the regulation of oncogenes/reprogramming factors-drived glioma cell plasticity by cell autonomous UPR. Our study will provide novel insights into the mechanisms of glioma carcinogenesis and possibly raise new targeted intervention ways for the disease.

胶质瘤是最难治的肿瘤之一。癌基因/重编程因子驱动下细胞获得可塑性，即去分化为胶质瘤起始样细胞并维持原始特性，是胶质瘤发生发展的根源。细胞自主性未折叠蛋白反应（unfolded protein response，UPR）的启动是癌基因/重编程因子驱动下细胞转化过程的必须行为，但机制不详。本项目在以往研究的基础上首次提出细胞自主性UPR对癌基因/重编程因子驱动下胶质瘤细胞可塑性具有重要调控。拟在胶质瘤起始细胞及癌基因/重编程因子驱动下的胶质瘤细胞中检测细胞自主性UPR启动，观察抑制UPR兴趣分子后细胞未分化状态和致瘤能力等可塑性指标的变化，利用Chip-on-Chip技术获取UPR兴趣分子直接调控细胞可塑性的兴趣靶基因及UPR兴趣分子对癌基因/重编程因子转录活性的影响，探索并验证UPR调控癌基因/重编程因子驱动下胶质瘤细胞可塑性的分子机制。本研究将对揭示胶质瘤发生机制及针对性干预提供新思路。

理解肿瘤与微环境的相互作用对肿瘤治疗有重要意义。低氧应激是胶质瘤等实体肿瘤体内微环境的重要特征，在这种应激环境下，胶质瘤能量代谢发生显著改变，这对肿瘤发生发展至关重要。 XBP1剪接是多种实体瘤在体内低氧应激下生存的必须行为，研究表明 XBP1 与细胞代谢关系密切，且剪接型 XBP1 可直接或间接调控大量糖酵解相关基因，但 XBP1 在胶质瘤中的生物学意义并不明确。通过实验证实了，XBP1s在胶质母细胞瘤瘤中高表达；在低氧应激环境下，抑制XBP1表达阻碍了胶质瘤细胞的增殖和代谢水平；在抑制氧化磷酸化条件下，抑制XBP1的表达可以有效地抑制胶质瘤细胞的糖酵解能力；在细胞应激条件下，抑制XBP1表达抑制了HK2升高的趋势；体内试验中，敲除XBP1的胶质瘤细胞的生长被抑制。PERK通路是也是UPR重要的下游通路，在应激环境下通过其磷酸化激活可以起到细胞保护作用。通过我们的实验，证实了PERK通路在保护肿瘤细胞的同时，具有调控胶质瘤细胞糖代谢的功能。p-PERK在胶质母细胞瘤瘤中高表达,且其表达与胶质瘤患者的生存期成负相关；在低糖应激环境下，抑制PERK表达阻碍了胶质瘤细胞的增殖能力；在低糖应激环境下，抑制PERK表达的胶质瘤细胞可通过EGF回复其p-AKT表达能力并恢复其细胞活性；在低糖应激环境下，抑制PERK表达抑制了HK2向线粒体转位的能力；体内试验中，敲除PERK的胶质瘤细胞的生长被抑制。除此之外，本项目还对胶质瘤干细胞特性进行了一些研究：本项目还进行了与胶质瘤相关的其他研究：mir-212-3p靶向SGK3抑制胶质瘤细胞增殖；胶质瘤细胞中应用自噬诱导剂后阻断自噬不同阶段可产生不同效果；T7肽功能化聚乙二醇-PLGA胶束负载卡介苗靶向治疗胶质瘤；阻滞TRAP1表达调控代谢重编程促进恶性胶质瘤细胞替莫唑胺的化疗敏感性。共发表SCI收录论文7篇，获抗癌协会一等奖1项；培养博士研究生2名。