Oxidative Stress and Hepatocellular Carcinoma

描述（由申请方提供）：该提案基于以下假设：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，抗氧化能力降低会增加慢性肝病患者发生HCC的可能性。因此，本提案的长期目标是确定丙型肝炎（HCV）感染导致氧化应激介导的HCC发展的机制，并确定与HCC进展相关的风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）和肝癌的发展之间的因果关系;几个小鼠模型产生的重演肝癌的发展被证明有氧化损伤水平升高;和突变小鼠与基因缺陷的氧自由基代谢发展肝癌后，长时间的孵育时间。总的来说，这些研究表明，氧化应激可能在慢性肝病中HCC的发展中发挥直接和重要的作用。我们将集中研究HCV介导的HCC发展、氧化应激和SOD缺乏之间的相互作用。提出了三个具体的目标，以确定HCV感染，ROS的产生，钙稳态，和肝癌发生之间的关系，以确定SOD在HCV介导的肝癌发生的发展中的作用，并确定共同的慢性HCV感染和SOD缺乏的分子靶点，通过比较蛋白质组学分析。将使用已建立的人肝细胞系、原代人肝细胞、HCV转基因小鼠和CuZnSOD缺陷小鼠进行体外和体内研究，以确定HCV蛋白对ROS产生、钙稳态和氧化还原敏感性信号分子活化的影响。一种遗传方法将被用来降低HCV转基因小鼠的SOD水平，以调节HCC的发展过程。此外，将实施不同的蛋白质组学工具和程序，以确定在HCV转基因和CuZnSOD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.