胞外CypB抑制p53通路促进胶质母细胞瘤适应谷氨酰胺剥夺微环境的机制研究

胶质母细胞瘤（GBM）增殖过程中依赖谷氨酰胺（Gln）代谢。而血管生成滞后造成GBM核心区域Gln缺失。尚不清楚GBM适应Gln剥夺微环境的机制。前期发现Gln剥夺微环境诱导GBM细胞分泌CypB，而胞外CypB降低氧化磷酸化，促进葡萄糖摄取和乳酸转化。基于此，我们推测胞外CypB通过控制糖酵解和线粒体氧化磷酸化之间的代谢平衡增强乳酸分泌，而高乳酸促进GBM适应Gln剥夺微环境。为了验证该假设，本项目将基于基因敲除细胞、转基因斑马鱼和裸鼠原位移植瘤模型，采用细胞能量检测、小动物活体成像和时间延迟成像等技术分析胞外CypB抑制p53通路对GBM细胞糖酵解和线粒体氧化磷酸化的调控作用。构建体内外高乳酸环境，分析高乳酸对GBM适应Gln剥夺微环境的影响。基于Gln感受器，观察Gln时空变化对GBM增殖的影响及分析CypB的调控作用。本项目有望为GBM难治性和耐药性提供潜在治疗靶点和理论依据。

The proliferation of glioblastoma (GBM) depends heavily on glutamine (Gln) metabolism. However, the lag of angiogenesis results in the extreme loss of Gln in the core area of GBM. It is not clear how GBM can maintain its growth in this microenvironment. It was found that Gln deprivation induced GBM cells to secrete CypB. Extracellular CypB promotes glucose uptake and lactate transformation, resulting in increased mitochondrial fragments and decreased membrane potential. Based on this, we speculated that extracellular CypB could promote GBM adapts to Gln deprivation microenvironment by controlling the metabolic balance between glycolysis and mitochondrial oxidative phosphorylation，promoting GBM to adapt to Gln deprivation microenvironment by enhancing lactate secretion..In order to test the hypothesis, based on the model of knockout cells, transgenic zebrafish and orthotopic transplanted tumor in nude mice, the project will use cell energy analysis, live imaging of small animals and time delay imaging to analyze the effect of extracellular CypB on GBM glycolysis and mitochondrial oxidative phosphorylation, and clarify the regulatory effect of extracellular CypB on p53 pathway. The effects of high lactate on the adaptation of GBM to the Gln deprivation microenvironment were studied by constructing a high lactate environment in vitro and in vivo. Based on Gln receptor, time-delay imaging technology was used to visually observe the influence of Gln time-space changes on GBM proliferation and analyze the role of CypB. This project is expected to provide potential therapeutic targets and theoretical basis for GBM.