Dishevelled蛋白表达及其与人脑胶质瘤增殖与侵袭的相关性研究

发布时间：2018-12-24 13:30

【摘要】：脑胶质瘤是人类恶性肿瘤中最具有侵袭性的肿瘤之一。组织病理学分型高的恶性胶质瘤患者预后极差，如多形性胶质母细胞瘤（glioblastomamultifome,GBM）,即使给予外科手术治疗并辅以放化疗，其死亡率也很高，极大地威胁着患者的生命。因而，能够发现人脑胶质瘤病理诊断和基因治疗意义的新靶点，改善其恶性生物学行为，为攻克这一疾病有着重要的临床应用价值。经典的Wnt/β-catenin信号通路在人等动物胚胎的早期发育，器官形成，组织再生和其他生理过程中具有至关重要的作用，如果这条信号通路中的关键蛋白发生突变，则导致信号异常活化，可能诱导疾病的发生[7-8]。近期研究表明，在脑胶质瘤的形成和发展过程当中，，Wnt/β-catenin信号通路发挥了十分重要的作用[9]。 Dishevelled蛋白是Wnt/β-catenin信号通路中位于β-catenin上游的正向调节因子。它通过与大肠腺瘤息肉样蛋白(APC)，轴抑制蛋白(Axin)，糖原合酶激酶-3β(GSK3β)等降解复合体相结合，抑制GSK3β对β-catenin的磷酸化，从而抑制β-catenin的降解，使胞浆内游离的β-catenin水平升高，β-catenin继而进入胞核，与T细胞因子(TCF)/淋巴增强因子(LEF)家族结合而激活Wnt靶基因的转录[10-11]，引起细胞异常增殖，最终致使细胞发生癌变。但目前该蛋白与人脑胶质瘤相关性的研究国内外鲜有报道。目的：探讨Dishevelled蛋白在人脑胶质瘤中的表达情况，分析其表达水平与临床病理级别的关系；以及Dishevelled蛋白表达与人脑胶质瘤细胞增殖、侵袭的相关性。方法：本研究分为两个部分： 1．使用免疫组化、免疫印迹（Western-blot）方法检测Dishevelled蛋白在67例不同病理级别人脑胶质瘤标本和3例正常人脑组织中的表达水平。 2．选取67例脑胶质瘤组织标本，采用免疫组化方法检测Dishevelled蛋白的表达，评定Dishevelled蛋白免疫反应评分（immunoreactivity score，IRS）、增殖指数（proliferation index，PI）、侵袭指数（invasion index，II），并分析其相关性。结果： 1．在正常人脑组织中均未见Dishevelled蛋白表达，而在人脑胶质瘤组织中Dishevelled蛋白高表达，67例胶质瘤中，Dishevelled阳性率为65.67%（44/67）；且Dishevelled蛋白表达水平均随着脑胶质瘤病理级别的增高而显著升高（P0.05)。 2．人脑胶质瘤中Dishevelled蛋白IRS、PI、II分别为3.463.45、30.9317.92、20.4311.79，均随人脑胶质瘤病理级别的增高而明显升高（P0.001)，Dishevelled蛋白阳性组PI、II明显高于Dishevelled蛋白阴性组（P0.001)。PI、II与Dishevelled蛋白IRS呈显著正相关，PI与IRS相关系数r=0.930；II与IRS相关系数r=0.882。显示，人脑胶质瘤的PI、II随着脑胶质瘤的级别的增高而升高。结论：Dishevelled蛋白高表达可能与人脑胶质瘤的发生、发展密切相关，且Dishevelled蛋白的高表达在胶质瘤的增殖和侵袭中起到了重要作用，Dishevelled蛋白有望成为人脑胶质瘤分子诊断的标记物以及人脑胶质瘤基因治疗的理想靶点。
[Abstract]:Glioma is one of the most aggressive tumors in human malignant tumors. The prognosis of malignant glioma patients with high histopathological classification is very poor, such as glioblastoma pleomorphic (glioblastomamultifome,GBM), even if surgical treatment and radiotherapy and chemotherapy, its mortality is also very high, which greatly threatens the life of patients. Therefore, it has important clinical application value to find new targets for pathological diagnosis and gene therapy of human glioma and to improve its malignant biological behavior. The classical Wnt/ 尾-catenin signaling pathway plays an important role in the early development of human embryos, organ formation, tissue regeneration and other physiological processes, if the key proteins in this signaling pathway mutate. This may lead to abnormal signal activation and may induce disease [7-8]. Recent studies have shown that Wnt/ 尾-catenin signaling pathway plays a very important role in the formation and development of gliomas. Dishevelled protein is a positive regulatory factor in Wnt/ 尾-catenin signaling pathway upstream of 尾-catenin. It inhibits the phosphorylation of 尾-catenin by binding to the degradation complex such as (Axin), glycogen synthase kinase 3 尾 (GSK3 尾), a polypoid protein (APC), axis inhibitor of colorectal adenoma, and thus inhibits the degradation of 尾-catenin. The level of free 尾-catenin in the cytoplasm was increased, and 尾-catenin then entered the nucleus, which combined with the T cytokine (TCF) / lymphoid enhancer (LEF) family and activated the transcription of Wnt target gene [10-11], which led to abnormal cell proliferation. Eventually, the cells become cancerous. However, there are few reports about the correlation between this protein and human glioma at home and abroad. Aim: to investigate the expression of Dishevelled protein in human glioma and analyze the relationship between the expression level and clinicopathological grade, and the relationship between the expression of Dishevelled protein and the proliferation and invasion of human glioma cells. Methods: this study was divided into two parts: 1. The expression of Dishevelled protein in 67 cases of gliomas with different pathological grades and 3 cases of normal human brain tissues were detected by immunohistochemistry and Western blot (Western-blot). 2. The expression of Dishevelled protein was detected by immunohistochemical method in 67 cases of gliomas, and Dishevelled protein immunoreactive score (immunoreactivity score,IRS), proliferation index (proliferation index,PI), invasion index (invasion index,II) were evaluated. And analyze its correlation. Results: 1. There was no expression of Dishevelled protein in normal human brain tissue, but high expression of Dishevelled protein in human glioma tissue. The positive rate of Dishevelled was 65.67% (44 / 67) in 67 cases of glioma. The expression of Dishevelled protein increased with the increase of pathological grade of glioma (P0.05). 2. The IRS,PI,II of Dishevelled protein in human glioma was 3.463.45,30.9317.92 and 20.4311.79, respectively, which were significantly increased with the increase of pathological grade of glioma (P0.001), Dishevelled protein positive group PI,). II was significantly higher than that in Dishevelled negative group (P0.001). There was a significant positive correlation between PI,II and Dishevelled IRS, and the correlation coefficient between PI and IRS was 0.930; The correlation coefficient between II and IRS was 0.882. The results showed that the PI,II of human glioma increased with the increase of glioma grade. Conclusion: the overexpression of Dishevelled protein may be closely related to the occurrence and development of human glioma, and the overexpression of Dishevelled protein may play an important role in the proliferation and invasion of glioma. Dishevelled protein is expected to be a marker for molecular diagnosis of human glioma and an ideal target for gene therapy of human glioma.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R739.41

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