THE MECHANISMS OF CELL TRANSFORMATION INDUCED BY HEPATITIS CVIRUS

病毒性肝炎病毒诱导细胞转化的机制

基本信息

批准号：
09670325
负责人：
HIJIKATA Makoto
金额：
$ 1.73万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

To reveal the molecular mechanisms of hepatitis and hepatocellular carcinoma closely related with the infection of hepatitis C virus (HCV), we investigated the changes of the gene expression in the HCV protein producing cultured cells originated from hepatocytes and analyzed the cellular factor interacting with HCV genome and its gene products. The results are followed ;1. We found a cellular factor interacting with the terminal fragment of HCV genome in the cell lysate by U.V.cross link method. We showed that the factor was the polypyrimidine tract binding protein.2. We obtained HepG2 cells producing a HCV proteins after specific concentration of the transiently plasmid transfected cells. The mRNA samples from the cells with and without HCV protein production were used for dot blothybridization experiment using more than 500 fragments of the cellular genes as targets. However no drastic change of the expression was found.3. We found that the concentrated HepG2 cells producing HCV prot … More eins became resistant against Fas and tumor necrosis factor (TNF)-alpha mediated apoptosis This function was appeared to be responsible to the core protein among a HCV proteins.4. We revealed that the core protein functioned as an anti-apoptotic factor by synergistic enhancement of NF-kappaB activity induced by apoptotic signals, anti Fas antibody and TNF-alpha in certain cells. We also found that there was a NF-kappaB-independent anti-apoptotic pathway by HCV core protein.5. We showed that the core protein have a potential to transform a certain cells cooperatively with an oncogenic protein, Ras.6. The core protein was revealed to have a potential to activate the cell proliferation through the activation of MAP kinase cascade. We consider that the anti-apoptotic effect and transforming potential of the core protein may contribute to the persistent infection of HCV and cause of hepatocellular carcinoma.Further analysis of molecular mechanisms of these functions of the core protein is underway. Less

为了揭示与丙型肝炎病毒（HCV）感染密切相关的肝炎和肝细胞癌的分子机制，我们研究了源自肝细胞的产生HCV蛋白的培养细胞中基因表达的变化，并分析了与HCV基因组相互作用的细胞因子。其结果如下： 1．我们通过紫外交联法在细胞裂解物中发现了与HCV基因组末端片段相互作用的细胞因子。 2.在特定浓度的瞬时质粒转染细胞后，我们获得了产生HCV蛋白的HepG2细胞。使用来自产生和不产生HCV蛋白的细胞的mRNA样品，使用超过500个细胞片段进行斑点杂交实验。基因作为靶标，但没有发现表达的剧烈变化。3。我们发现产生HCV prot的浓缩HepG2细胞对Fas和肿瘤产生了抗性坏死因子(TNF)-α介导的细胞凋亡这一功能似乎与HCV蛋白中的核心蛋白有关。4．我们发现核心蛋白通过协同增强TNF-αB诱导的活性发挥抗凋亡因子的作用。某些细胞中的凋亡信号、抗Fas抗体和TNF-α我们还发现HCV核心蛋白存在不依赖于NF-κB的抗凋亡途径。5．表明核心蛋白具有与致癌蛋白Ras协同转化某些细胞的潜力。6．核心蛋白被揭示具有通过激活MAP激酶级联来激活细胞增殖的潜力。 -核心蛋白的凋亡作用和转化潜力可能有助于HCV的持续感染和肝细胞癌的发生。对核心蛋白这些功能的分子机制的进一步分析正在进行中。