茯苓酸对胃癌治疗机制的研究

发布时间：2018-04-20 15:48

本文选题：茯苓酸 + 胃癌　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：研究目的:近年来的研究表明茯苓酸(PA)有多种药理活性,特别是在抗肿瘤方面,发现其对多种癌细胞有明显的抑制作用。然而,对茯苓酸潜在靶点尤其是其抗肿瘤作用靶点的识别以及靶点的后续验证研究仍然十分匮乏。本研究拟通过两个系统性的药物靶点预测方法,对茯苓酸进行潜在的靶点预测,再经映射到蛋白质互作后通过构建分子网络筛选关键靶点,最后借助实验手段进行实验验证及机制分析,为寻找药物抗癌治疗靶点提供新思路,进一步给临床应用提供一定的实验依据。方法:首先,以中药分子茯苓酸为研究对象,分别用SysDT和WES这两个药物-靶点预测的计算机模型,来预测茯苓酸的潜在靶点;然后将得到的潜在靶点与胃癌相关基因的整合结果映射到蛋白质相互作用数据库BioGRID和STRING中,再经Cytoscape软件构建分子网络从中选取中心基因作为可能的抗胃癌作用靶点;最后利用细胞热转移(CETSA)和western-blot方法在胃癌细胞上进行关键靶标蛋白的结合实验验证及抗癌作用机制的初步探究。结果:(1)整合Sys DT和WES模型预测结果,去重后共得到43个茯苓酸潜在靶点。(2)通过GCgene数据库和胃癌biomarker收集到胃癌相关基因1763个,进一步整合预测的茯苓酸潜在靶点与胃癌相关基因获得15个抗胃癌种子靶点。这些靶点映射蛋白质互作PPI网络和分子作用网络分析,最后根据网络拓扑学参数进行筛选,得到5个关键节点/靶点。(3)CETSA靶点结合实验结果表明茯苓酸在胃癌细胞中能结合到PPARγ从而改变其热稳定性;Western-blot分析显示经茯苓酸处理后的PPARγ蛋白表达上调,且具有浓度依赖性;另外,还发现PPARγ抑制剂GW9662预处理能影响茯苓酸对Cyclin D1、Bcl-2、Bcl-x L、CDK4、p-ERK1/2、p-p38的表达。结论:茯苓酸在胃癌细胞中能结合PPARγ,进一步上调其蛋白表达。PPARγ作为茯苓酸的抗胃癌作用靶点,其涉及的胃癌治疗机制很可能是通过调控一些周期和凋亡相关因子及丝裂原活化蛋白激酶(MAPK)信号通路相关蛋白;而这些因子或蛋白在胃癌的发生与发展有着重要的作用。本研究的成功开展将为中药成分的靶点预测提供新的策略,对中药成分抗癌的机制研究具有重要的指导意义,将促进中药的现代化发展。
[Abstract]:Objective: in recent years, studies have shown that PAA has many pharmacological activities, especially in the aspect of anti-tumor, and it has obvious inhibitory effect on many kinds of cancer cells. However, the identification and subsequent verification of the potential targets of Poria cocos, especially their antitumor effects, are still scarce. In this study, two systematic drug target prediction methods were used to predict the potential targets of Poria cocos, and then to screen the key targets by constructing a molecular network after mapping to protein interaction. Finally, experimental verification and mechanism analysis were carried out by means of experimental means, which provided a new idea for finding the target of anticancer therapy and provided certain experimental basis for clinical application. Methods: firstly, the computer models of SysDT and WES were used to predict the potential targets of Poria cocos. Then the integration results of the potential target and gastric cancer related gene were mapped to the protein interaction database BioGRID and STRING, and then the molecular network was constructed by Cytoscape software to select the center gene as the possible anti-gastric cancer target. Finally, the binding experiments of key target proteins in gastric cancer cells were carried out by cell heat transfer assay (CTSA) and western-blot method, and the mechanism of anticancer action was explored. Results the predicted results of Sys DT and WES model were integrated, and 43 potential targets of Poria were obtained. 1763 genes related to gastric cancer were collected by GCgene database and gastric cancer biomarker. Further integration of the predicted potential target of Poria and gastric cancer related genes to obtain 15 anti-gastric cancer seed targets. These target mapping protein interaction PPI networks and molecular interaction networks were analyzed, and finally selected according to the network topology parameters. The results of five key nodes / target. The results showed that Poria cocos acid could bind to PPAR 纬 in gastric cancer cells and change its thermal stability. Western-blot analysis showed that the expression of PPAR 纬 protein was up-regulated and concentration-dependent after the treatment of Poria cocos acid. In addition, it was found that GW9662 pretreatment with PPAR 纬 inhibitor could affect the expression of p-ERK1 / 2p38 in Cyclin D1Bcl-2Bcl-x CDK4T. Conclusion: Poria cocos acid can bind to PPAR 纬 in gastric cancer cells, and further upregulate its protein expression. The mechanism involved in the treatment of gastric cancer is probably through the regulation of some cycle and apoptosis-related factors and mitogen-activated protein kinase MAPK signaling pathway related proteins which play an important role in the occurrence and development of gastric cancer. The successful development of this study will provide a new strategy for target prediction of Chinese traditional medicine components, and will be of great significance for the study of anticancer mechanism of Chinese traditional medicine ingredients, and will promote the modernization of traditional Chinese medicine.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R735.2

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