TRIM59在胃癌发生发展过程中的功能机制研究

发布时间：2018-03-19 04:14

本文选题：癌基因　切入点：胃癌　出处：《上海交通大学》2015年博士论文　论文类型：学位论文

【摘要】：目前,胃癌在世界范围内仍然是威胁人类健康的一大病症,尤其在发展中国家该种情况尤为明显。寻找能够用于胃癌早期诊断、治疗的分子靶标结合临床手术能够明显改善治疗效果。本课题主要从以下三部分,详细阐述TRIM59在胃癌中的表达情况,进一步探讨了TRIM59参与调控胃癌发生发展的生物学分子机制。有望将TRIM59作为一种崭新的分子靶标为临床诊断治疗提供一定的帮助。第一部分通过对多个数据库进行生物信息学检索分析发现,在诸多癌基因中位于3号染色体的TRIM家族成员TRIM59在胃癌中显著高表达,并且TRIM59的表达水平与病人的预后状况有显著的相关性。我们进一步通过对临床样本、组织芯片和胃癌细胞系中TRIM59的mRNA和蛋白表达水平检测发现,TRIM59在病人的胃癌组织中的表达水平高于在癌旁组织中的表达水平,胃癌细胞系中的TRIM59表达水平也明显高于胃粘膜正常上皮细胞(GES-1)。第二部分通过体外、体内功能性实验发现,TRIM59促进肿瘤细胞的增殖、克隆形成和迁移以及裸鼠体内成瘤。我们通过RT-PCR和western blot功能机制验证发现,干扰TRIM59基因的表达,细胞的恶性程度降低,相应的调控肿瘤恶性增殖转移相关的信号通路的活性也有所降低。此外,通过对TRIM59和p53调控的信号通路中主要成分的表达分析发现两者之间具有明显的负相关性。进一步对临床样本的相关因子检测发现,TRIM59与p53蛋白及下游的调控分子的表达水平也具有明显的负相关性。第三部分通过免疫共沉淀、蛋白质半衰期检测等功能实验验证发现,TRIM59可以与抑癌基因p53蛋白相互结合,促进p53由蛋白酶体依赖的泛素化降解过程,进而调节p53的蛋白稳定性,影响其下游基因的表达最终促进了肿瘤的发生、发展。综上所述,我们发现一个新的胃癌标志物TRIM59,通过拟合TRIM59表达水平与病人临床症状相关性发现,TRIM59可以作为鉴定胃癌发生发展的诊断分子,有望为临床诊断提供一定的参考意义。其次,我们通过功能验证实验发现,TRIM59可以激活肿瘤发展相关信号通路,促进癌细胞的增殖、克隆形成、迁移和裸鼠体内成瘤。最后,我们发现TRIM59是通过调节p53的泛素化水平,影响p53蛋白的稳定性,进而影响p53蛋白的转录活性促使肿瘤发生发展。这些研究可以为临床诊断治疗提供一定的依据。
[Abstract]:At present, gastric cancer remains a major threat to human health worldwide, especially in developing countries. Molecular target therapy combined with clinical surgery can significantly improve the therapeutic effect. In this paper, the expression of TRIM59 in gastric cancer is described in detail in the following three parts. The biological molecular mechanism of TRIM59 involved in the regulation of carcinogenesis and development of gastric cancer is further discussed. It is expected that TRIM59 will be used as a new molecular target for clinical diagnosis and treatment. The analysis of bioinformatics retrieval found that, TRIM59, a member of the TRIM family located on chromosome 3 of many oncogenes, was significantly overexpressed in gastric cancer, and the expression level of TRIM59 was significantly correlated with the prognosis of patients. The expression level of TRIM59 mRNA and protein in tissue microarray and gastric cancer cell line was higher than that in paracancerous tissue. The expression level of TRIM59 in gastric cancer cell line was also significantly higher than that in normal gastric mucosal epithelial cell line. In the second part, it was found that TRIM59 promoted the proliferation of tumor cells through in vitro functional experiments. Clone formation and migration as well as tumorigenesis in nude mice. We have found that interfering with the expression of TRIM59 gene reduces the malignancy of cells by verifying the functional mechanism of RT-PCR and western blot. The activity of signal pathway associated with malignant proliferation and metastasis is also decreased. By analyzing the expression of the main components in the signal pathway regulated by TRIM59 and p53, we found that there was a significant negative correlation between them. Further, we found that TRIM59, p53 protein and downstream regulatory molecules were detected by the correlation factor detection of clinical samples. The expression level was also negatively correlated. The third part was co-immunoprecipitation. Functional experiments, such as protein half-life detection, showed that TRIM59 could bind to p53 protein, promote the proteasome dependent Ubiquitin degradation process, and regulate the protein stability of p53. Affecting the expression of genes downstream of the tumor ultimately promotes the development of the tumor. We found a new marker of gastric cancer, TRIM59. by fitting the expression level of TRIM59 with the clinical symptoms of patients, we found that TRIM59 can be used as a diagnostic molecule to identify the occurrence and development of gastric cancer, and it is expected to provide a certain reference for clinical diagnosis. We found that TRIM59 can activate the signal pathway associated with tumor development, promote cancer cell proliferation, clone formation, migration and tumorigenesis in nude mice. Finally, we found that TRIM59 regulates the level of p53 ubiquification. The stability of p53 protein is affected, and the transcription activity of p53 protein is affected to promote the tumorigenesis and development. These studies can provide some evidences for clinical diagnosis and treatment.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R735.2

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