HBx整合基因表达蛋白调控乙肝相关肝内胆管癌血管新生的机制研究

肝内胆管癌（ICC）是预后极差的常见消化系统恶性肿瘤。近年来，乙型肝炎病毒（HBV）感染被公认为ICC重要诱因之一，然而对该病的临床表型和分子机理尚缺乏认识。申请人前期发现HBV相关ICC是一类具有明显生存优势的“富血供”肿瘤；HBV深度捕获测序表明病毒DNA的HBx片段可重复插入整合到宿主胆管上皮细胞基因组；预试验提示HBx可能通过反式调控HIF-1α启动人端粒酶逆转录酶（hTERT）介导的血管新生。本研究计划（1）在前期发现HBV相关ICC临床表型特点（血管新生）及生存预后基础上鉴定HBV DNA插入整合位点及HBx对宿主转录组的调控；（2）阐明HBx以非经典途径（缺氧非依赖）调控HIF-1α反式激活hTERT的作用机制；（3）揭示hTERT的非端粒功能在HBV相关ICC血管新生中的核心作用。项目的顺利实施有望从病因学层面出发，为降低ICC发生率、改善长期预后提供了抗血管新生的新途径。

Intrahepatic cholangiocarcinoma (ICC) represents a common digestive malignant tumor with poor prognosis. Recently, hepatitis B virus (HBV) infection has been gradually recognized as one of the risk factors for ICC. However, there is still a lack of understanding of the clinical phenotype and molecular mechanism of such disease. The applicant has previously found that HBV-related ICC is a kind of "blood supply-rich" tumor with obvious survival advantage. HBV-capturing deep sequencing showed that HBx fragment of viral DNA could be recurrently inserted and integrated into the host biliary epithelial cell genome. Furthermore, our preliminary study suggested that HBx might initiate human telomerase reverse transcriptase (hTERT) mediated angiogenesis through trans regulation of HIF-1α. First of all, this study plans to identify the site of HBV-DNA insertion and integration, as well as HBx regulating effect on the host transcriptome on the basis of the understanding about the clinical phenotype (angiogenesis) and prognosis of HBV-related ICC. Secondly, the applicant attempts to illustrate the trans effect and mechanism of HIF-1α on hTERT by HBx regulation in non-classical pathway (a hypoxia independent route) in vitro and in vivo. Finally, the core role of non-telomeric function of hTERT in the angiogenesis of HBV-related ICC will be illustrated. The successful implementation of the project is expected to etiologically provide new routes for reducing the incidence of ICC and improving long-term prognosis by anti-angiogenesis.