结肠癌中PKM2和STAT3的相互作用机制研究

In cancer cells, pyruvate from glycolysis was released to extracellular regions after converted to lactic acid, while it was oxidized in mitochondria respiratory chain in normal cells. The different destiny of pyruvate was usually called Warburg effect（aerobic glycolysis）. One of pyruvate kinase variants, PKM2, played essential roles in aerobic glycolysis and tumor genesis. However, the mechanisms involved in these processes in unclear till now. The Onco-protein STAT3 may promote aerobic glycolysis in cells. We have found that PKM2 and STAT3 could interact with each other directly, and our previous results showed that STAT3 could up regulate the expression of PKM2.With human colon tumor cells, we have got STAT3 and PKM2 specific knockdown cell lines by gene targeting and lentvirus RNAi vectors ,as well as several reversed cell lines. We will focus on the mechanisms of interaction between STAT3 and PKM2, and the effects on regulation of cell metabolism and proliferation in cancers. We will collect and analyze clinical samples of colon cancer, study the expression and distribution of PKM2 and STAT3, as well as their relationship with livability of patients after surgeries.At the same time, through the computer simulation, find out the PKM2 and STAT3 interaction sites, according to the interaction between the two sites, the use of computer simulation of docking of small molecules, to find out the possible blocked this effect of small molecular group.

肿瘤细胞中糖酵解产生的丙酮酸主要转化为乳酸排出细胞外，而在正常细胞中丙酮酸主要进入线粒体氧化呼吸链，这一现象被称作Warburg效应(有氧糖酵解)。丙酮酸激酶的一个变体PKM2对于有氧糖酵解和肿瘤发生起着关键的作用，但是PKM2的作用机制尚不清楚。原癌基因STAT3也可以引起细胞发生有氧糖酵解。通过实验我们发现PKM2和STAT3直接相互作用,并且STAT3可以调节PKM2 的表达。本研究以人结肠癌细胞为研究对象，通过基因打靶和慢病毒介导的RNA干扰构建了STAT3和PKM2的沉默细胞株。在此基础上我们将采集和分析临床结肠癌病样，分析PKM2和STAT3的表达与分布情况，以及其与患者术后存活率的关系。同时，通过计算机模拟，找出PKM2和STAT3相互作用位点，根据两者相互作用位点，使用计算机进行小分子模拟对接，找出可能阻断这种作用的小分子群。

本项目按照研究计划执行科研任务。根据制订的研究内容及计划，已成功利用慢病毒载体介导的RNA干扰沉默PKM2表达，并初步分析了PKM2与STAT3通路的关系。同时我们通过计算机模拟找到了两者的作用位点；通过免疫组化观察到PKM2在结肠癌组织中的表达及定位。