GnT-IVa与黏附分子及肝癌细胞侵袭和迁移关系的初探

发布时间：2018-01-01 10:15

本文关键词：GnT-IVa与黏附分子及肝癌细胞侵袭和迁移关系的初探　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：糖,作为继DNA、RNA和蛋白质之后的第四类生物大分子,在生物体中发挥着极其重要的作用。糖链结构的异常与多种肿瘤的形成有关,具有特定结构的糖链还可作为肿瘤诊断的生物标志物,因此,近年来对催化生成糖链结构的糖基转移酶的研究呈快速上升趋势。有文献报道,Gn T-III和Gn T-V催化的N-聚糖结构重塑对cadherin和integrin介导的细胞黏附和迁移起着正向或负向的调控作用,但关于Gn T-IVa对cadherin与integrin作用的研究报道较少。早期研究发现,肝癌组织中N-乙酰氨基葡萄糖转移酶IVa(Gn T-IVa)的表达比癌旁组织中明显增强,当用si RNA对mgat4a基因进行干扰沉默时,发现肝癌细胞BEl-7402的运动能力发生了变化,这表明Gn T-IVa可能与肝癌的运动相关。在前期研究的基础上,采用RNAi方法,研究Gn T-IVa基因在BEl-7402细胞中表达下调后,细胞表面integrinβ1的表达和糖链的变化情况。免疫荧光实验和western实验结果表明,Gn T-IVa表达变化前后,integrinβ1在细胞中的表达和定位没有明显变化。对integrinβ1的糖链进行分析,结果发现Gn T-IVa表达下调后,BEL-7402细胞中integrinβ1糖链发生了改变。同时,本实验采用粘附实验及流式细胞凋亡试验研究Gn T-IVa表达下调所引起的BEL-7402细胞的生物学功能改变,结果发现,Gn T-IVa表达沉默后,细胞粘附能力增强,但细胞没有明显凋亡的迹象。同时,本实验还分析了Gn T-IVa对与细胞侵袭迁移密切相关的信号通路中若干信号蛋白的影响,结果表明,Gn T-IVa表达下调导致BEl-7402细胞中β-catenin表达增强,P-ERK2表达降低。表明Gn T-IVa可能对细胞中信号通路产生一定影响。本研究以integrinβ1为切入点,初步分析了Gn T-IVa表达变化引起细胞运动能力改变的分子机制,为深入研究糖链和Gn T-IVa的细胞生物学功能提供了新的思路。
[Abstract]:Sugar, as a kind of 4th biological macromolecules after DNA RNA and protein, plays an extremely important role in organism. The abnormal structure of sugar chain is related to the formation of many kinds of tumors. Sugar chain with specific structure can also be used as a biomarker for tumor diagnosis. Therefore, the study of glycosyltransferase catalyzing the formation of sugar chain structure has been increasing rapidly in recent years, which has been reported in literature. Gn-T-III and Gn-T-V catalyzed structural remodeling of N-glycan play a positive or negative role in cell adhesion and migration mediated by cadherin and integrin. However, there are few reports on the effects of Gn T-IVa on cadherin and integrin. The expression of N-acetylglucosamine transferase (IVa(Gn T-IVa) in HCC tissues was significantly higher than that in adjacent tissues, when the mgat4a gene was silenced by si RNA. It was found that the motility of BEl-7402 was changed, which suggested that GnT-IVa might be related to the motility of HCC. Based on the previous studies, RNAi method was used. To study the down-regulation of Gn T-IVa gene expression in BEl-7402 cells. The expression of integrin 尾 1 and the changes of sugar chain on the cell surface. The results of immunofluorescence assay and western assay showed that the expression of GnT-IVa was changed before and after the change of GnT-IVa expression. The expression and localization of integrin 尾 1 did not change significantly. The analysis of the sugar chain of integrin 尾 1 showed that the expression of GnT-IVa was down-regulated. The sugar chain of integrin 尾 1 in BEL-7402 cells was changed. The biological function of BEL-7402 cells induced by down-regulation of GnT-IVa expression was studied by adhesion assay and flow cytometry. After the expression of Gn T-IVa was silenced, cell adhesion was enhanced, but there was no obvious sign of apoptosis. The effects of GnT-IVa on some signal proteins in the signal pathway closely related to cell invasion and migration were also analyzed. The expression of 尾 -catenin in BEl-7402 cells was enhanced by down-regulation of GnT-IVa expression. The decreased expression of P-ERK2 suggests that GnT-IVa may have an effect on the signal pathway in cells. In this study, integrin 尾 1 was used as the starting point. The molecular mechanism of the change of cell motility caused by the change of GnT-IVa expression was preliminarily analyzed, which provided a new idea for the further study of the cellular biological function of glucose chain and GnT-IVa.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R735.7

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