新型RNAi文库筛查抗HBx致肝前体细胞恶性转化功能基因的研究

Hepatitis B virus X(HBx) has been implicated as a multifunctional virus regulatory factor of Hepatitis B virus (HBV) and is known to be essential for HBV-induced carcinogenesis. However, the specific mechanisms of HBx induced tumorigenicity in HCC are needed further investigation. The first key point of investigation the mechanism of HBx-mediated liver tumor formation should focus on the identification and confirmation the founctional genes which are related to tumorigenicity. Direct functional screening at a high-throughput scale is an important method to indentify the key gene of regulatory factor and has its special superiority in genetic screening. In this study, a novel RNA interference library screening was applied to develop tumor by implanting the library-treated HBx-expressing hepatic progenitor cells into the subcutaneous tissue of nude mice. Based on these, we can directly search for anti tumorigenicity functional gene which inhibit HBx-induced hepatocellular malignant transformation. Next, we will carry on the research of candidate genes on verification and biological function. A random loss-of-function library screening was applied to induce tumor-like phenotypes of HBx-expressing hepatic progenitor cells. It provides a simple and direct method for targeting founctional genes which could inhibit tumorigenicity of hepatocellular induced by HBx. It would help to indentify new molecules, including tumor suppressors, modulators involving signal transduction pathways and non-coding RNAs. The implementation of this project might not only enriches the biological function of HBx and molecular mechanism of HBx-induced development of liver disease, but also provides the idea for diagnosis, treatment and prevention of HBV-related disease and therapeutic targets.

HBx是HBV病毒重要的功能调控蛋白，具有促进肝细胞转化为肝细胞癌的功能，但其确切致病机理尚有待进一步阐明。与HBx促恶性转化有关的功能基因的识别和确定是探索其致癌作用分子机理的首个重点。大规模、高通量功能基因直接筛选在寻找新的调控关键基因方面有其特殊的优越性。课题构想在HBx促恶性转化功能基因筛查中引入一种新型RNAi文库，构建裸鼠皮下移植肿瘤模型，直接靶向抗HBx恶性转化基因，筛选抑制HBx诱发肝细胞恶性转化的强效基因，并对所筛出基因进行功能验证和机制研究。本研究通过建立随机的功能缺陷文库，经过系统的表型筛选，直接靶向能抑制HBx诱发肝细胞恶性转化的功能基因，从而更有利于发现包括肿瘤抑制基因、信号转导通路调控分子、非编码 RNA 等在内的新分子。期待能丰富HBx 的生物学功能及其引发肝病发生和发展的分子机制，为进一步探索HBV相关疾病的防诊治研究奠定基础。

肝癌是一种致死率较高的常见恶性肿瘤疾病，其预防和治疗是目前研究的热点。HBx是HBV病毒重要的功能调控蛋白，其调控肝前体细胞增殖、恶性转化的机制及其与肝细胞癌发生之间的关系仍未阐释清楚。该项目通过引入一种新型RNAi文库，将核心蛋白聚糖（DCN）鉴定为一种能抑制Hbx诱发肝前体细胞增殖以及恶性转化的功能分子，发现当DCN表达下调后，促进了HBx介导的肝前体细胞恶性转化并能致瘤，并探讨了其作用机制，对HBV相关性肝癌的早期诊断和靶向治疗提供了新依据。