Sorcin与Stathmin相互作用及其在胃癌多药耐药机制中的研究

Multidrug resistance (MDR) describes a phenomenon of cross-resistance of tumor cells to several structurally unrelated chemotherapeutic agents after exposure to a single cytotoxic drug. Resistance to anticancer drugs is a major obstacle preventing the effective treatment of tumors. In our previous works, using a proteomic approach Stathmin was identified as Sorcin-interacting proteins. However, many important questions are still unanswered. For example, in the regulatory mechanisms of multidrug resistance in gastric cancer, what is the relationship between the Stathmin and Sorcin? In the current case, in vivo and in vitro interactions between Sorcin and Stathmin will be confirmed by standard immunoprecipitation and GST pull-down assays. An analysis of Sorcin deletion constructs will show the exact amino acids of Sorcin, which were responsible for binding to Stathmin. In addition, to gain insight into the molecular action of Stathmin in multidrug resistance, we will perform a systematic proteomic analysis of Stathmin -associated proteins in MDR cells of gastric cancer , which recently developed, termed quantitative immunoprecipitation combined with knockdown, integrates RNAi, iTRAQ, immunoprecipitation, and quantitative MS technologies. Using this system coupled with bioinformatics a protein interaction map of Stathmin was generated. These data were valuable for further to study the mechanism of multidrug resistance in gastric cancer.

肿瘤多药耐药是指肿瘤细胞接触一种化疗药物并对其产生耐药后，同时对其他化学结构和作用机制不同的化疗药物亦产生耐药。肿瘤多药耐药是肿瘤化疗失败最主要的原因之一。最近我们的研究首次发现Sorcin与Stathmin在胃癌耐药细胞中存在相互作用，那么两者结合对于胃癌的多药耐药性有何影响？本项目拟采用一系列分子生物学的方法研究Sorcin与Stathmin物理性和功能性相互作用，进一步应用免疫共沉淀结合稳定同位素标记以及质谱分析技术，通过生物信息学，在胃癌多药耐药细胞模型中鉴定与Stathmin结合的相互作用蛋白复合体，描绘出Stathmin在胃癌多药耐药细胞的相互作用蛋白质网络，以期揭示其参与胃癌多药耐药，胃癌细胞周期及其凋亡的调控机制。

肿瘤细胞的多药耐药性（multidrug-resistance, MDR）是指肿瘤细胞接触一种化疗药物并对其产生耐药后，同时对其他化学结构和作用机制不同的化疗药物亦产生耐药。MDR往往是多因素参与、多种机制同时存在的事件，而且不同机制间常相互影响。MDR产生机制的研究内容涉及到药物的外排增加和亚细胞分布改变、药物作用靶标如拓扑异构酶改变、细胞的损伤修复能力增强、抗凋亡相关通路的改变、细胞增殖速率变化，以及体内药代动力学因素等等一系列的问题。肿瘤多药耐药是肿瘤化疗失败最主要的原因之一。我们的早期研究发现Sorcin与Stathmin在胃癌耐药细胞中存在直接相互作用，那么两者结合对于胃癌的多药耐药性有何影响？本项目采用一系列分子生物学的方法研究Sorcin与Stathmin物理性和功能性相互作用，进一步应用免疫共沉淀结合稳定同位素标记以及质谱分析技术，通过生物信息学，在胃癌多药耐药细胞模型中鉴定与Stathmin结合的相互作用蛋白复合体，描绘出Stathmin在胃癌多药耐药细胞的相互作用蛋白质网络，以期揭示其参与胃癌多药耐药，胃癌细胞周期及其凋亡的调控机制。在我们的研究中，首次揭示及描绘了了Sorcin与Stathmin相互作用复合体，并进一步证实该蛋白质复合体通过调节STAT3的磷酸化活性，共同作用于STAT3通路，参与了多药耐药机制的形成。