胃癌基因生物标志物的调控和功能及其临床相关研究

发布时间：2018-02-11 19:32

本文关键词： 胃癌 ATP6V1A 转录调控预后生物标志物预后评分　出处：《南京医科大学》2017年博士论文　论文类型：学位论文

【摘要】：胃癌是当今世界最常见的恶性肿瘤之一,其发病率高、易侵袭和转移、临床症状严重和低治愈率等特性导致其成为严重的世界健康问题。胃癌发病率排在肺癌、乳腺癌、结肠直肠癌和前列腺癌之后占居第五名。这些数据表明胃癌已对人类健康构成重大威胁,并成为经济和社会发展的重大阻碍。目前,治疗胃癌的主要手段是手术切除,早期胃癌患者的五年生存率超过90%。但是,大部分胃癌患者明确诊断时已处于进展期并已经失去了放疗机会,导致五年生存率降至只有11-40%。因此,胃癌研究的当务之急是提高胃癌患者的早期诊断率和开发新的分子靶向药物来治疗和预防胃癌的转移和复发。最新研究表明胃癌(gastric cancer,GC)的侵袭和转移与多亚基液泡H+-ATPase(V-ATPase)密切相关。本研究探讨了编码V-ATPase中催化亚基A的人类ATP6V1A基因在胃癌中的表达和作用。我们发现,与正常组织相比,胃癌中ATP6V1A表达水平显著增高,但ATP6V1A表达水平较高的胃癌患者预后较好。基因组分析显示,在小部分胃癌患者中APT6V1A的拷贝数增加,并且在极少量胃癌中丢失。此外,ATP6V14的拷贝数与mRNA水平呈正相关。为了寻找ATP6V1A在胃癌基因中过度表达的额外机制,我们研究了转录因子YY1和ATP6V1A之间的关系,并发现YY1的mRNA表达与ATP6V1A表达密切相关。为了证明YY1能转录调节ATP6Y1A我们发现ATP6V1A的核心启动子区域内包含三个YY1结合位点,在胃癌细胞中由RNAi介导的YY1沉默会显著减少ATP6V1A的mRNA和蛋白质表达,而YY1过度表达则会增加ATP6V1A的表达水平。并通过一系列的实验证实了 YY1与ATP6V1A启动子区中YY1结合位点的相互作用。总之,YY1可能在与胃癌潜在机制和临床意义相关的ATP6V14表达中起着重要的调节作用,且较高的ATP6V1A表达水平有利于胃癌的良好预后。为了进一步开发胃癌预后相关的基因生物标志,我们利用基因表达模式分析帮助确定一组基因生物标志物以预测临床结果,并发现潜在的治疗新靶点。本研究采用了多步骤生物信息学分析方法,以建立新的胃癌预后评分体系。我们首先确认了 276个在正常和胃癌组织中表达有显著差异的基因,通过单一变量Cox回归分析,发现其中249个基因与总生存期(Overall Survival,OS)显着相关。这249个基因的生物学功能涉及到细胞周期、RNA/非编码RNA加工、乙酰化和细胞外基质组成。在265个胃癌基因中,建立了 249个基因表达相关模型网络。我们采用典型判别分析法确定了一组由53个基因组成的胃癌预后生物标志物,并根据53个基因的典型判别函数建立了预后评分体系。预后评分能准确预测胃癌患者的总生存期情况。最后,我们对53个基因中的FHOD1基因在胃癌中的功能和作用进行了研究。发现FHOD1的表达对胃癌细胞的增殖、侵袭和转移、凋亡有显著的影响。总之,本研究发现的胃癌预后生物标志物揭示了个体肿瘤的生物学特性,可更准确的预测该肿瘤的行为。建立的预后评分体系可为胃癌精准医疗开辟广阔的前景。
[Abstract]:Gastric cancer is one of the world's most common malignant tumor, its incidence rate is high, easy invasion and metastasis, clinical symptoms are severe and the low cure rate and other characteristics of the world lead to serious health problems. The incidence of gastric cancer in lung cancer, breast cancer, colorectal cancer and prostate cancer after occupying fifth. These data suggest that gastric cancer is a major threat to human health, and has become a major obstacle to economic and social development. At present, the main means for the treatment of gastric cancer is surgical resection, patients with early gastric cancer five years survival rate is more than 90%., but the majority of cancer patients diagnosed is in progress and has lost the opportunity to radiotherapy five year survival rate. To only 11-40%. therefore, a pressing matter of the moment of the research is to improve gastric cancer metastasis and recurrence rate of early diagnosis and the development of new molecular targeted drugs for the treatment and prevention of gastric cancer in patients with gastric cancer. New research shows that gastric cancer (gastric cancer, GC) in the invasion and metastasis of H+-ATPase (V-ATPase) and Doyaki vacuoles are closely related. This study investigated the expression and function of human ATP6V1A gene encoding V-ATPase catalytic subunit A in gastric carcinoma. We found that, compared with the normal tissues, the expression level of ATP6V1A in gastric cancer was significantly increased, but the expression of ATP6V1A in patients with gastric cancer prognosis better. Higher levels of genome analysis showed that the copy number of APT6V1A in a small part of the increase in gastric cancer patients, and lost in the very small amount of gastric cancer. In addition, the copy number of ATP6V14 and mRNA levels were positively correlated. In order to find additional mechanisms of overexpression of ATP6V1A in gastric cancer genes, we studied the relationship between the between the transcription factor YY1 and ATP6V1A, and found that YY1 mRNA expression is closely related with the expression of ATP6V1A. In order to prove that YY1 can regulate transcription of ATP6Y1A we found that the ATP6V1A core promoter The sub region contains three YY1 binding sites, mediated by RNAi in human gastric cancer cells YY1 silencing can significantly reduce the expression of mRNA and protein ATP6V1A, whereas overexpression of YY1 could increase the expression of ATP6V1A. And confirmed the interaction between YY1 and ATP6V1A in the promoter region of YY1 binding sites through a series of experiments. In short, YY1 in gastric cancer and the potential mechanism and clinical significance of the expression of ATP6V14 plays an important role in the regulation of the high expression level of ATP6V1A and a good prognosis for gastric cancer. In order to further the development of gastric cancer related genes have marker gene expression pattern analysis, we use a group of genes that help determine biomarkers in order to predict the clinical outcome, and find new therapeutic target potential. This study adopts multi-step bioinformatics analysis methods to establish a new scoring system. Firstly, the prognosis of gastric cancer Confirmation of the 276 gene expression were significantly different in normal and cancer tissues by single variable Cox regression analysis found that 249 genes and overall survival (Overall, Survival, OS) was significantly correlated. The biological function of these 249 genes involved in cell cycle, non encoding RNA processing RNA/, acetylation and the extracellular matrix composition. In 265 gastric cancer genes, established 249 gene expression related to model network. We use the canonical discriminant analysis method to determine the prognosis of gastric cancer biological group consists of 53 gene markers, and discriminant function established prognostic scoring system according to the typical 53 genes can accurately predict the prognosis score. Overall survival of patients with gastric cancer. Finally, we studied the function of FHOD1 gene in 53 genes in gastric carcinoma. The expression of FHOD1 on gastric cancer cell proliferation, invasion and metastasis. Death has a significant impact. In conclusion, the biomarker of gastric cancer revealed by this study reveals the biological characteristics of individual tumors, and can predict the behavior of tumors more accurately. The established scoring system of prognosis has broad prospects for precision medical treatment of gastric cancer.

【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R735.2

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