IDH2基因通过选择性剪接调控肿瘤细胞发生EMT的研究

Epithelial-mesenchymal transition (EMT) is traditionally considered to promote cancer progression through enhancing cell migration and invasion. Recent research also shows that EMT enhances anti-apoptosis of cells and endows cells with chemoresistance. Changes in the splicing profiles of genes frequently occur in the EMT. And abnormal metabolism is an important factor that contributes to the progression of cancer. In previous research, we found that there is a switch in the splicing outcome of Isocitrate Dehydrogenase 2 (IDH2), a rate-limiting enzyme in tricarboxylic acid cycle (TCA). And the splicing switch of IDH2 was further proved to be essential for EMT. This program aims to identify the molecular mechanism of the splicing switch of IDH2 in the EMT. Firstly, we will explore the relationship between the splicing switch of IDH2 and the EMT; Secondly we will investigate the molecular pathways regulated by the two isoforms and study the differences in the enzymatic activities, stabilities and the binding activity of the substrates to the proteins encoded by the two isoforms; Thirdly we will identify the upstream molecules regulating the splicing of IDH2; And finally we will test the effects of splicing switch of IDH2 in rats. By incorporating gene alternative splicing and metabolism, this programme would enrich our understanding of cancer in theory and would be helpful for the diagnosis and treatment of cancer.

传统理论认为上皮间质转化（EMT）促进肿瘤的迁移和浸润，最新研究也表明EMT提高肿瘤细胞抗凋亡能力和耐药性，基因的剪接方式常常伴随EMT发生改变。细胞代谢水平的改变是肿瘤发展过程中的重要方面，异柠檬酸脱氢酶（IDH2）是三羧酸循环中的一种关键限速酶，我们在前期研究中发现，IDH2基因的剪接方式在EMT过程中改变，也发现不同的选择性剪接所编码的IDH2蛋白是EMT的重要调控因子。本项目拟对IDH2通过选择性剪接调控肿瘤细胞发生EMT的分子机制进行探讨。我们将首先分析IDH2基因剪接方式的转换与EMT之间的关系；然后比较两种异构体在酶活性、亚细胞定位和所调控的信号通路等方面的差异；继而寻找调控IDH2剪接的上游分子；最后通过小鼠荷瘤实验对IDH2两种异构体的功能进行验证。本研究将基因选择性剪接和代谢在肿瘤发展中的作用有机整合，具有理论价值，对肿瘤的临床诊断和治疗也具有参考价值。