TRAP1调控能量代谢模式转化维持胶质瘤干细胞干性的机制研究

The cancer stem cell (CSC) have been proposed to be responsible for aggressive phenotype of cancer, and be considered as potential cancer therapeutic target. Recent data have demonstrated that metabolic reprogramming could actually drive tumorigenesis and stemness. However, the metabolic feature of CSCs and the mechanisms involved in the regulation of their stem cell-like properties remain elusive. We have analyzed the mitochondrial protein samples from glioma stem cells (GSCs)/non-GSC cell pairs using proteomic approach, and identified several differentially expressed proteins, including TNF receptor-associated protein (TRAP1). Some studies have identified TRAP-1 as a central regulator of metabolic switch between mitochondrial respiration and aerobic glycolysis. What role TRAP1 plays in metabolic alterations is dependent on tumor type. We intend to use large scale of clinical samples to analyze the relationship between TRAP1 and glioma, and the prognostic value. We will further study the regulatory role of TRAP1 in metabolic alterations, self-renewing and tumor formation capacity of glioma stem cells in vivo and in vitro. Next we will explore the protein-protein interaction between TRAP1 and the client protein by GST pull-down assay and Co-IP analysis, study the relationship between TRAP1, energy metabolism and glioma stem cell properties. The implementation of this project, will provide in-depth understanding of the relationships between underlying metabolic alterations and mechanisms of maintenance of stemness of glioma stem cells, and probably raise new targeted intervention ways for the gliomas.

肿瘤干细胞被视为是肿瘤恶性表型的根源和潜在治疗靶点，近期研究表明能量代谢重编程可以驱动肿瘤发生并且和肿瘤干细胞的干性相关，但具体机制尚不清楚。本项目在前期工作中通过高通量荧光差异双向电泳技术筛选到了胶质瘤干细胞与非干细胞的线粒体差异表达蛋白TRAP1。TRAP1是细胞氧化磷酸化与糖酵解代谢互相转化的关键调控因子，其作用方式和生物学效应与肿瘤类型有关。本项目拟从大样本回顾性分析中总结TRAP1对于胶质瘤的临床相关性和预后判断价值；在细胞和动物模型中观察抑制TRAP1后胶质瘤干细胞能量代谢模式、自我更新能力和致瘤能力等变化；利用GST pull-down、Co-IP等技术验证TRAP1与能量代谢相关客户蛋白的相互作用，明确其对胶质瘤干细胞能量代谢的调控机制；深入探讨TRAP1、能量代谢与胶质瘤干细胞生物学特性之间的关系。本研究将对揭示代谢重编程与胶质瘤干细胞特性相关性及针对性干预提供新思路。

肿瘤干细胞被视为是肿瘤恶性表型的根源和潜在治疗靶点，近期研究表明能量代谢重编程可以驱动肿瘤发生并且和肿瘤干细胞的干性相关，但具体机制尚不清楚。本项目研究发现肿瘤坏死因子受体相关蛋白1(tumor necrosis factor receptor-associated protein1，TRAP1)对胶质瘤干细胞能量代谢相关分子具有调控作用，是胶质瘤干细胞能量代谢转换的关键调节分子，TRAP1可能参与胶质瘤干细胞的干性维持，TRAP1通过调节糖酵解相关酶的表达，参与胶质瘤干细胞代谢重编程过程的调节。在此基础上，以热休克蛋白家族HSP70-TRAP1（HSP75）系统作为治疗靶点，设计选择性诱导肿瘤细胞凋亡的抗肿瘤多肽，该多肽能与热休克元件（HSE）结合，竞争性阻止热休克因子1（HSF1）与HSE的结合，使HSF1失去转录活性，从而抑制HSP70-TRAP1（HSP75）系统活性。在体内外实验中均验证其具有很好的抗肿瘤作用。TRAP1作为胶质瘤干细胞能量代谢转换的关键调节分子，也通过影响胶质瘤细胞外泌体内容物的释放来影响肿瘤微环境。我们通过microRNA芯片分析了TRAP1高表达及TRAP1表达沉默的胶质瘤细胞分泌的外泌体中microRNA表达谱，发现其通过多种途径影响肿瘤微环境。本项目深入探讨了TRAP1、能量代谢与胶质瘤干细胞生物学特性之间的关系，对揭示代谢重编程与胶质瘤干细胞特性相关性及针对性干预提供新思路。