YBX1与G3BP1相互作用调控能量代谢促进肾细胞癌增殖及转移的分子机制研究

Abnormal energy metabolism plays an important role in cancer progression. In our previous study, we discovered that Y-box binding protein-1 (YBX1) is a key signaling molecule in renal cell carcinoma (RCC) progression. However, the molecular mechanism of YBX1 regulating RCC progression is not clear. In our preliminary study, we found that overexpression of YBX1 in RCC significantly enhanced cell glycolysis. YBX1 could interact with Ras-GAP SH3 domain-binding protein 1 (G3BP1), and, inhibited β subunit of mitochondria F1F0-ATP synthase (β-F1-ATPase) mRNA translation and promoted osteopontin (OPN) mRNA stability, which are the key mediators of cellular oxidative phosphorylation and glycolysis respectively. Therefore, we hypothesize that YBX1 could interact with G3BP1 to regulate the proliferation and metastasis of RCC by inhibiting oxidative phosphorylation and promoting glycolysis. In this study, RCC cell lines and xenograft mouse model will be used to verify the biological functions of YBX1 and G3BP1 interaction in the regulation of cell energy metabolism, proliferation and invasion. At the same time, the interaction between YBX1 and G3BP1 and their roles in regulating β-F1-ATPase and OPN will be confirmed. In addition, the metabolic spectrum regulated by YBX1 and G3BP1 will be identified. Finally, the protein and/or RNA expressions of the key molecules in YBX1 and G3BP1-regulated metabolic pathways will be analyzed in RCC clinical specimens, and their clinical correlates with patient prognosis will be validated. This study will shed light on a new mechanism by which the interaction of YBX1 and G3BP1 regulates cell energy metabolism and RCC progression, and provide novel target for developing anti-cancer targeted drugs.

异常能量代谢在肿瘤发生发展中起重要作用。本课题组既往研究发现YBX1是调控肾癌进展的关键蛋白，但其作用机制尚待研究。前期研究显示肾癌中YBX1过表达促进细胞糖酵解；YBX1可与G3BP1结合；二者可抑制β-F1-ATPase mRNA的翻译，提高OPN mRNA的稳定性。我们推测YBX1与G3BP1蛋白相互作用调节能量代谢相关信号通路，抑制氧化磷酸化，促进有氧糖酵解，进而促进了肾癌的增殖及转移。本项目将在细胞及原位肾癌动物模型中研究YBX1与G3BP1相互作用调控肾癌能量代谢进而调节增殖及转移的作用；探讨二者相互作用调节β-F1-ATPase及OPN的分子机制；分析它们对其他代谢通路的影响；结合临床数据检测相关通路蛋白及RNA在肾癌组织标本中的表达及与患者预后的关系。本项目将解析YBX1与G3BP1相互作用调控细胞能量代谢和肾癌进展的分子机制，为探索靶向抗肿瘤药物靶点提供理论依据。

本课题组既往研究发现YBX1是调控肾癌进展的关键蛋白，但其作用机制尚待研究。本项目在细胞及原位肾癌动物模型中研究YBX1与G3BP1相互作用，及其调控肾癌能量代谢，调节增殖及转移的作用；探讨二者相互作用调节SPP1的分子机制；解析YBX1调控ROS生成及调节LDHA作用的机制；分析它们对其他代谢通路的影响；结合临床数据检测相关通路蛋白在肾癌组织标本中的表达及与患者预后的关系。研究发现YBX1降表达抑制肾癌细胞的增殖、黏附、迁移和侵袭能力。与对应的癌旁组织相比较，YBX1、G3BP1和SPP1在肾癌组织中表达升高，且YBX1的表达与G3BP1和SPP1的表达显著正相关。在肾癌裸鼠移植瘤模型中，YBX1与G3BP1定位在细胞质中。在肾癌细胞中，YBX1与G3BP1相互作用通过调控SPP1激活下游的NF-κB信号通路调控肾癌的转移。此外，在肾癌细胞中YBX1与Kindlin-2相互作用且调节Kindlin-2的表达。在肾癌组织中二者的表达显著相关。YBX1通过Kindlin-2调节ROS生成以及肾癌细胞的凋亡。在肿瘤能量代谢方面，YBX1参与调控肾细胞癌糖代谢途径。YBX1和LDHA均在肾细胞癌中高表达，且两者表达呈正相关。同时，YBX1与LDHA的表达与肾癌临床进展相关。YBX1调控肾细胞癌糖代谢的分子机制可能与LDHA相互作用且可调控LDHA的表达有关。本项目解析YBX1与G3BP1相互作用及其调控细胞能量代谢和肾癌进展的分子机制，为探索靶向抗肿瘤药物靶点提供理论依据。