顺铂（Cisplatin）通过线粒体和内质网凋亡信号通路诱导神经胶质瘤凋亡

发布时间：2018-05-18 00:15

本文选题：CDDP + 神经胶质瘤　；参考：《吉林大学》2014年硕士论文

【摘要】：细胞凋亡（apoptosis）又称程序性细胞死亡（Programmed Cell Death, PCD），是指细胞受到某种信号或受到某些因素刺激后，发生的一种为维持内环境稳定的主动性消亡过程。目前研究发现Caspases和Bcl-2蛋白超家族是参与细胞凋亡的两种核心蛋白家族。研究表明Caspases诱导细胞凋亡的途径主要有三种：1）死亡受体途径（外源性）的细胞凋亡；2）线粒体途径（内源性途径）的细胞凋亡；3）内质网应激途径的细胞凋亡。除此之外，Bcl-2家族蛋白在凋亡发生中也发挥重要作用，在凋亡刺激时，Bax/Bak转位到线粒体膜上，促进细胞色素C由线粒体内膜间隙释放到胞质中，诱导细胞凋亡的发生。除此之外，内质网应激相关的凋亡途径也在逐渐被研究。内质网（ER）通过控制蛋白的折叠和运输在关键的细胞功能中发挥作用。当细胞内有大量错误折叠蛋白堆积时，就会导致内质网应激的发生，通常有一种机制可以缓解内质网应激，称为未折叠蛋白反应（UPR），哺乳动物中内质网应激时引起的UPR反应通路包括PKR-样内质网定位的真核起始因子2（eIF2）-a激酶（PERK），肌醇需求酶1（IRE-1），，和活化转录因子6（ATF6）。在非应激细胞中，这些蛋白通过与它们的内质网结合分子伴侣蛋白，葡萄糖调节蛋白GRP78/免疫球蛋白重链（GRP78）结合以失活结构存在。当内质网中的未折叠蛋白增加时，GRP78从PERK，ATF6和IRE1释放，激活三个内质网应激感受器。内质网应激发生时，尤其是PERK的活化，主要是通过真核起始因子（eIF2）-a的磷酸化，导致核C/EBP-同源蛋白（CHOP）的诱导，值得我们关注的是目前CHOP已经被作为不同病理条件下内质网应激诱导细胞死亡的关键介质。顺铂是目前临床使用最常见和最有效的化疗药物，对很多实体瘤都有良好的治疗效果，但是顺铂引起肿瘤细胞凋亡的机制是复杂的，可能有线粒体途径的参与，也可能有内质网途径的参与。在神经胶质瘤T98G和U251细胞中，CDDP能否引起两种细胞凋亡？是通过线粒体凋亡途径还是通过内质网应激-凋亡途径引起的两种细胞的凋亡？目前，对于这些方面的研究还未见报道。因此，本课题将针对这两个问题展开研究。本课题拟通过体外培养人神经胶质瘤T98G和U251细胞，探讨CDDP对T98G和U251细胞生存率的影响，以及其引起的两种细胞中凋亡相关蛋白Cleaved Caspase3和Cleaved PARP的变化。此外，本研究将进一步探讨CDDP在两种细胞中对其线粒体凋亡相关蛋白细胞色素C，Bcl-2及Bax表达的影响，同时研究CDDP在两种细胞中对内质网应激-凋亡相关蛋白GRP78及CHOP表达的影响。本研究将有可能为临床上脑胶质瘤的治疗提供一定的理论依据。
[Abstract]:Apoptosis is also called programmed Cell death (PCDX), which refers to an active process of cell death which occurs when cells are stimulated by some signal or by some factors to maintain the stability of the internal environment. Currently, Caspases and Bcl-2 protein superfamily are two core protein families involved in apoptosis. The results showed that there were three kinds of apoptosis pathway induced by Caspases: 1) death receptor pathway (exogenous) apoptosis 2) mitochondria pathway (endogenous pathway) apoptosis 3) endoplasmic reticulum stress pathway apoptosis. In addition, Bcl-2 family proteins also play an important role in apoptosis. During apoptosis stimulation, Bax-Bak translocation into mitochondria membrane, promote cytochrome C release from mitochondrial intima to cytoplasm, induce apoptosis. In addition, endoplasmic reticulum stress-related apoptotic pathways are gradually being studied. Endoplasmic reticulum ERs play a role in key cellular functions by controlling the folding and transport of proteins. When there is a large accumulation of misfolded proteins in the cell, it can lead to endoplasmic reticulum stress, and there is usually a mechanism to relieve endoplasmic reticulum stress. The UPR pathway induced by endoplasmic reticulum stress in mammals, known as unfolded protein response, includes PKR-like endoplasmic reticulum localization eukaryotic initiation factor 2(eIF2)-a kinase PERKN, inositol demanding enzyme 1, IRE-1, and activated transcription factor 6, ATF6. In non-stress cells, these proteins are inactivated by binding to their endoplasmic reticulum binding molecular chaperone protein and glucose-regulated protein GRP78/ immunoglobulin heavy chain GRP78. When the unfolded protein in the endoplasmic reticulum increased, the GRP78 was released from PERKN ATF6 and IRE1 and activated three endoplasmic reticulum stress receptors. The activation of endoplasmic reticulum (ER), especially PERK, is mainly induced by phosphorylation of eIF2a, the nucleocapsid C / EBP- homologue protein (CHOPP), during the stress of endoplasmic reticulum (ER). We should pay attention to the fact that CHOP has been used as the key mediators of endoplasmic reticulum stress induced cell death under different pathological conditions. Cisplatin is the most common and effective chemotherapeutic drug currently used in clinic. It has a good therapeutic effect on many solid tumors. However, the mechanism of apoptosis induced by cisplatin is complicated, which may involve mitochondrial pathway. The endoplasmic reticulum pathway may also be involved. Can CDDP induce apoptosis in glioma T98G and U251 cells? Is it through the mitochondrial apoptosis pathway or through the endoplasmic reticulum stress-apoptosis pathway of the two kinds of cell apoptosis? At present, the research on these aspects has not been reported. Therefore, this subject will focus on these two problems. The aim of this study was to investigate the effect of CDDP on survival rate of T98G and U251 cells and the changes of apoptosis-related proteins Cleaved Caspase3 and Cleaved PARP in human glioma T98G and U251 cells induced by T98G and U251 cells in vitro. In addition, the effects of CDDP on the expression of mitochondrial apoptosis-related protein cytochrome C _ 2 and Bax in two kinds of cells, and the effect of CDDP on the expression of ER stress-apoptosis-related protein GRP78 and CHOP in two kinds of cells were studied. This study may provide a theoretical basis for the clinical treatment of gliomas.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R739.41

【共引文献】