4EGI-1诱导结直肠癌细胞凋亡及其分子机制研究

发布时间：2018-04-30 06:42

本文选题：结直肠癌 + 小分子抑制剂4EGI-1　；参考：《山西医科大学》2017年硕士论文

【摘要】：结直肠癌(colorectal cancer,CRC)是常见的消化系统恶性肿瘤之一。据估计全世界范围内每年大约有新增病例1,360,000例,其中死亡达694,000例。2015年中国癌症中心统计数据报导,结直肠癌的发病率以及致死率在所有恶性肿瘤中高居第五位。传统结直肠癌治疗手段,如放疗与化疗,对结直肠癌中晚期患者治疗疗效差,后期产生耐药性且会对患者机体免疫系统造成伤害,给患者身心带来痛苦。真核细胞翻译起始因子4E(eukaryotic translation initiation factor 4E,e IF4E)是真核生物帽状依赖性蛋白质翻译起始阶段的限速分子与翻译调控的核心成分,e IF4E与真核细胞翻译起始因子4G(eukaryotic translation initiation factor 4G,e IF4G)、ATP依赖的RNA解旋酶e IF4A组装形成的复合物e IF4F对与肿瘤细胞生长、增殖相关基因的表达起着关键的调控作用。e IF4E结合蛋白1(e IF4E-binding protein 1,4EBP1)通过与e IF4G竞争性结合e IF4E而负调控e IF4F的组装。由于癌细胞依靠新生蛋白来维持快速生长,因此,靶向蛋白合成机制治疗癌症策略已引起广泛关注。小分子抑制剂4EGI-1因阻碍e IF4E与e IF4G的结合,同时促进4EBP1与e IF4E的结合,阻碍蛋白质翻译进程进而起到显著的抗肿瘤效果。目前,4EGI-1已经在乳腺癌、慢性淋巴细胞白血病、鼻咽癌、神经胶质瘤等不同的肿瘤细胞中均被证实有抗肿瘤作用,而4EGI-1对结直肠癌的影响则鲜有报道,故本研究采用小分子抑制剂4EGI-1作用于结直肠癌细胞,探讨了4EGI-1对结直肠癌细胞增殖、凋亡的影响及其作用的分子机制,以期为结直肠癌的靶向治疗提供科学依据。方法:1.用不同浓度的4EGI-1处理结直肠癌细胞,采用MTT、流式细胞术以及western blot技术检测4EGI-1对结直肠癌细胞增殖,凋亡的影响。2.用不同浓度的4EGI-1处理结直肠癌细胞,采用Western blot技术检测肿瘤凋亡相关蛋白cleaved-PARP,caspase-3,Bcl-2,Puma以及Noxa等蛋白的表达。3.免疫共沉淀(Co-Immunoprecipitation,Co-IP)的方法检测4EGI-1对e IF4E与e IF4G表达的影响。结果:1.4EGI-1抑制结直肠癌细胞增殖。2.4EGI-1增强cleaved-Caspase3和cleaved-PARP的表达,诱导结直肠癌细胞凋亡。3.4EGI-1通过降低Bcl-2的表达而诱导结直肠癌细胞凋亡。4.4EGI-1可能降低了结直肠癌细胞e IF4G的表达。结论:小分子抑制剂4EGI-1可以抑制结直肠癌细胞的生长,促进结肠癌细胞的凋亡。其作用机制可能是通过下调抗凋亡蛋白Bcl-2的表达。
[Abstract]:Colorectal cancer CRC is one of the most common malignant tumors of digestive system. It is estimated that there are about 1360000 new cases every year worldwide, including 694000 deaths. In 2015, the China Cancer Center reported that the incidence and mortality of colorectal cancer ranked fifth among all malignant tumors. Traditional methods of treatment for colorectal cancer, such as radiotherapy and chemotherapy, have poor therapeutic effect on patients with advanced colorectal cancer, and will cause harm to the immune system of patients and bring pain to the patients' body and mind. Eukaryotic translation initiation factor 4E(eukaryotic translation initiation factor 4E e IF4E is the rate-limiting molecule and the core component of translation regulation in eukaryote capsiform dependent protein translation initiation stage and the eukaryotic cell translation initiation factor 4G(eukaryotic translation initiation factor 4GN e IF4G tasp. Lyme RNA helicase e IF4A assembles the complex e IF4F pair with tumor cell growth. The expression of proliferation-related genes plays a key role in regulating the assembly of e IF4F by competitive binding of e IF4E with e IF4G. As cancer cells rely on new proteins to maintain rapid growth, targeted protein synthesis mechanisms for cancer treatment have attracted widespread attention. 4EGI-1, a small molecule inhibitor, inhibits the binding of e IF4E to e IF4G and promotes the binding of 4EBP1 to e IF4E, which hinders the process of protein translation and thus plays a significant role in the anti-tumor effect. At present, EGI-1 has been proved to have anti-tumor effect in breast cancer, chronic lymphoblastic leukemia, nasopharyngeal carcinoma, glioma and other tumor cells, but the effect of 4EGI-1 on colorectal cancer is rarely reported. In order to provide scientific basis for the targeted therapy of colorectal cancer, the effect of 4EGI-1 on the proliferation and apoptosis of colorectal cancer cells and its molecular mechanism were studied by using small molecule inhibitor 4EGI-1. Method 1: 1. Colorectal cancer cells were treated with different concentrations of 4EGI-1. The effects of 4EGI-1 on proliferation and apoptosis of colorectal cancer cells were detected by MTT, flow cytometry and western blot techniques. Colorectal cancer cells were treated with different concentrations of 4EGI-1. The expression of cleaved-PARPncaspase-3, Bcl-2Puma and Noxa were detected by Western blot technique. Co-immunoprecipitation Co-IP) was used to detect the effect of 4EGI-1 on the expression of e IF4E and e IF4G. Results: 1. 1. 4 EGI-1 inhibited the proliferation of colorectal cancer cells. 2.4EGI-1 enhanced the expression of cleaved-Caspase3 and cleaved-PARP, and induced apoptosis of colorectal cancer cells. 3.4EGI-1 induced apoptosis of colorectal cancer cells by decreasing the expression of Bcl-2. 4.4EGI-1 may decrease the expression of e IF4G in colorectal cancer cells. Conclusion: small molecule inhibitor 4EGI-1 can inhibit the growth of colorectal cancer cells and promote the apoptosis of colon cancer cells. Its mechanism may be by down-regulating the expression of anti-apoptotic protein Bcl-2.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R735.34

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