ROCK/PTEN/PI3K介导的cofilin-1线粒体转位在左金丸逆转胃癌耐药中的作用

Drug resistance is the major reason for treatment failure in clinical chemotherapy of gastric cancer. The traditional Chinese Medicine, Zuo jin wan (ZJW), has been suggested to improve the sensitivey of gastric cancer cells to cisplatin (DDP), and the underlying mechanisms are associated with increased mitochondrial translocation of cofilin-1. However, the upstream signaling pathways are still unknown. Given our previous study on activated ROCK/PTEN signaling induced by ZJW and the important role of ROCK/PTEN/PI3K signaling in regulating cofilin-1 mitochondrial translocation, we have the hypothesis that ROCK/PTEN/PI3K mediated cofilin-1 mitochondrial tranlocation participates in ZJW's pro-apoptotic effect on gastric cancer cells. In this project, immunohistochemistry, flow cytometry, immunoprecipitation, and other biological methods will be used to study the effects of ZJW on ROCK/PTEN/PI3K/cofilin-1 signaling and the underlying molecular mechanisms in vivo and in vitro. Moreover, susceptibility testing for DDP and ZJW will be performed by using fresh human gastric biopsy. This project will provide the experimental and theoretical evidences for the application of ZJW in the adjunctive therapy of gastric cancer.

胃癌患者化疗过程中出现耐药是临床亟需解决的难题。前期研究发现中药复方左金丸能够提高胃癌耐药细胞对顺铂的敏感性，其机制与增加cofilin-1线粒体转位有关；然而，确切上游信号通路不明。我们通过蛋白芯片发现左金丸可上调胃癌耐药细胞ROCK/PTEN信号，鉴于ROCK/PTEN/PI3K可调控cofilin-1线粒体转位，我们假设左金丸可通过ROCK/PTEN/PI3K/cofilin-1线粒体转位信号通路发挥促胃癌耐药细胞凋亡作用。本课题拟应用免疫组化、流式细胞分析及免疫共沉淀等分子生物学方法考察左金丸对胃癌耐药细胞及裸鼠移植瘤模型中ROCK/PTEN/PI3K信号及其下游cofilin-1线粒体转位的影响及分子机制；并采用新鲜的人胃癌活体组织进行顺铂和左金丸的药敏实验，从临床角度考察左金丸对顺铂的增敏作用。左金丸逆转胃癌耐药分子机制的阐明，将为左金丸应用于胃癌的辅助治疗提供实验和理论依据。

胃癌患者化疗过程中出现耐药是临床亟需解决的难题。我们前期研究发现中药复方左金丸能够通过增加cofilin-1线粒体转位促进胃癌耐药细胞凋亡，提高胃癌耐药细胞对顺铂的敏感性，但具体机制不清。基于前期研究，本课题探讨左金丸是否通过 ROCK/PTEN/PI3K介导的cofilin-1 线粒体转位促进耐药细胞凋亡，并以新鲜的人胃癌活体组织为研究对象进行药敏试验，验证左金丸对顺铂耐药患者的潜在临床作用。研究发现：（1）左金丸通过激活PP1和PP2A诱导p-cofilin-1的去磷酸化、cofilin-1的线粒体转位，诱导胃癌耐药细胞凋亡；（2）左金丸激活ROCK／PTEN，抑制PI3K／Akt信号通路，促进PP1、PP2A的激活及cofilin-1的线粒体转位，从而诱导胃癌耐药细胞线粒体凋亡；（3）左金丸在整体动物水平可有效抑制胃癌顺铂耐药细胞的增殖并通过ROCK/PTEN/PI3K途径及 cofilin-1线粒体转位促进顺铂介导的细胞凋亡;（4）采用新鲜的人胃癌活体组织提取原代胃癌细胞，同样发现左金丸可促进cofilin-1线粒体转位诱导细胞凋亡。通过此项研究，阐明了左金丸通过调控ROCK/PTEN/PI3K/cofilin-1线粒体转位信号通路逆转胃癌耐药的分子机制，为胃癌的临床治疗提供新的作用靶点和治疗药物，也为揭示中药逆转耐药的物质基础和丰富中医治法提供了重要的科学依据。