Syntaphilin介导的线粒体分布对放疗抵抗的胶质瘤细胞迁移侵袭的影响及机制研究

The mitochondria in lamellipodia are crucial for the migration and invasion of tumor cells. Our previous study found that the migration and invasion capability of radiation resistant glioma cells (RRGC) increased significantly. There were more mitochondria in the peripheral region of RRGC and the expression of Syntaphilin (SNPH), one mitochondrial anchor protein, decreased significantly. So we hypothesize that down-regulation of SNPH expression promotes RRGC migration and invasion via increasing the mitochondrial content in lamellipodia. To explore how SNPH-mediated mitochondria distribution affects RRGC migration and invasion as well as the mechanism of SNPH down-regulation on multiple levels such as cytobiology, molecular biology and histopathology, various techniques will be applied in our research, including organelle fluorescent labeling, dynamic imaging of living cells and in vivo imaging. The findings of this study will enrich the theory for the effects of regional energy supply on tumor cell migration and invasion, broaden the research perspective on the participation of mitochondria trafficking in tumor migration and invasion, and provide novel therapeutic targets for inhibiting RRGC migration and invasion.

伪足内的线粒体对肿瘤细胞的迁移侵袭至关重要。我们的前期研究发现放疗抵抗的胶质瘤细胞（RRGC）迁移侵袭能力显著增强，线粒体多分布至细胞外周，且线粒体固定蛋白Syntaphilin（SNPH）的表达显著降低。由此，我们提出假设：SNPH下调通过升高伪足内线粒体的含量来提升RRGC的迁移侵袭能力。本课题拟通过细胞器荧光标记、活细胞动态成像和小动物活体成像等方法，从细胞生物学、分子生物学及组织病理学等多个层次研究SNPH介导的线粒体分布如何影响RRGC迁移侵袭以及RRGC内SNPH下调的机制。该课题将丰富局部能量供应影响肿瘤细胞迁移侵袭的理论，拓宽线粒体运输参与肿瘤迁移侵袭的研究视野，有助于为抑制RRGC迁移侵袭提供新的治疗靶点。

我们的前期研究发现放疗抵抗的胶质瘤细胞（RRGC）侵袭能力更强，线粒体多分布至细胞外周，并且线粒体固定蛋白Syntaphilin（SNPH）的含量显著降低，提示SNPH在放疗后的适应性下调可能在RRGC侵袭的过程中发挥了重要作用。本项目通过建立放疗抵抗的胶质瘤细胞系和裸鼠胶质瘤原位移植模型，应用慢病毒转染技术调控SNPH表达，从正反两方面，综合应用细胞器荧光标记、克隆形成、Transwell实验、Western Blot、流式细胞技术和免疫共沉淀等研究方法，发现放疗后SNPH的适应性下调能够诱导线粒体分布至外周，进而促进RRGC侵袭；泛素介导的蛋白降解能够促进RRGC内SNPH的适应性下调；SNPH对RRGC侵袭的调控作用依赖于粘着斑的活性及信号传递；上调RRGC内的SNPH能够导致放疗增敏。本项目将线粒体分布与细胞侵袭和放疗抵抗相联系，有助于寻找合适的干预靶点抑制RRGC迁移侵袭、促进放疗增敏，对于提高胶质瘤综合治疗效果，改善病人预后具有重要意义。