Oxidative Stress and Hepatocellular Carcinoma

描述(申请人提供)：这项建议是基于这样一种假设，即氧化应激和损伤是慢性肝病中肝细胞癌(HCC)的常见和主要驱动力，并且抗氧化能力降低会增加慢性肝病患者发生肝细胞癌的可能性。因此，这项建议的长期目标是确定丙型肝炎(丙型肝炎)感染中氧化应激介导的肝细胞癌发生的机制，并确定与肝细胞癌进展相关的危险因素和氧化应激介导的生物标志物。几项临床研究表明，低水平的超氧化物歧化酶(SOD)与肝癌的发展存在因果关系；几种用于概括肝癌发展的小鼠模型被证明具有较高的氧化损伤水平；具有氧自由基代谢遗传缺陷的突变小鼠在长时间孵育后患上肝癌。总之，这些研究表明，氧化应激在慢性肝病肝细胞癌的发生发展中可能起着直接而重要的作用。在这项研究中，我们将重点研究丙型肝炎病毒介导的肝癌发生、氧化应激和超氧化物歧化酶缺乏之间的相互作用。通过比较蛋白质组学分析，提出了三个特定的目标，以确定丙型肝炎病毒感染、ROS产生、钙稳态和肝癌发生之间的关系，确定超氧化物歧化酶在丙型肝炎病毒介导的肝癌发生发展中的作用，以及通过比较蛋白质组学分析确定慢性丙型肝炎病毒感染和超氧化物歧化酶缺乏的共同分子靶点。利用已建立的人肝细胞系、原代人肝细胞、丙型肝炎病毒转基因小鼠和铜锌超氧化物歧化酶缺陷小鼠进行体外和体内研究，以确定丙型肝炎病毒蛋白对ROS产生、钙稳态和氧化还原敏感信号分子激活的影响。将使用一种遗传方法来降低丙型肝炎转基因小鼠的超氧化物歧化酶水平，以调节肝癌的发展过程。此外，将采用不同的蛋白质组学工具和程序来识别在丙型肝炎病毒转基因和铜锌超氧化物歧化酶缺陷小鼠中易受氧化修饰的分子。

DESCRIPTION (provided by applicant): This proposal is based on the hypothesis that oxidative stress and injury is a common and major driving force of hepatocellular carcinoma (HCC) in chronic liver diseases and that decreased antioxidant capacity increases the probability of HCC development in patients with chronic liver diseases. Therefore, the long term objectives of this proposal are to determine the mechanism underling oxidative stress-mediated HCC development from hepatitis C (HCV) infection and to identify risk factors and oxidative stress-mediated biomarkers associated with the progression of HCC. Several clinical studies showed a causal relationship between low levels of superoxide dismutase (SOD) and the development of HCC; several mouse models generated to recapitulate HCC development were shown to have elevated levels of oxidative damage; and mutant mice with genetic defects in oxygen free radical metabolism develop HCC after a long incubation time. Collectively, these studies suggest that oxidative stress may play a direct and important role in the development of HCC in chronic liver diseases. We will focus our studies on the interplay between HCV-mediated HCC development, oxidative stress, and SOD deficiency in this proposal. Three Specific Aims are proposed to determine the relationship between HCV infection, ROS production, calcium homeostasis, and hepatocarcinogenesis, to determine the role of SOD in the development of HCV-mediated hepatocarcinogenesis, and to identify molecular targets common to chronic HCV infection and SOD deficiency by comparative proteomic analyses. In vitro and in vivo studies using established human liver cell line, primary human hepatocytes, HCV transgenic mice, and CuZnSOD deficient mice will be carried out to determine the effects of HCV proteins on ROS production, calcium homeostasis, and the activation of redox-sensitive signaling molecules. A genetic approach will be used to reduce SOD levels in HCV transgenic mice to modulate the course of HCC development. In addition, different proteomic tools and procedures will be implemented to identify molecules that are vulnerable to oxidative modification in HCV transgenic and CuZnSOD deficient mice.