Feng G X, Li J, Yang Z, Zhang S Q, Liu Y X, Zhang W Y, Ye L H, Zhang X D
State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, China.
State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin, China.
Oncogene. 2017 Dec 14;36(50):6895-6905. doi: 10.1038/onc.2017.291. Epub 2017 Aug 28.
Hepatitis B virus (HBV)-induced liver necrosis takes great part in liver cirrhosis progression. However, less is known about whether hepatitis B virus X protein (HBx) has effect on liver fibrosis. Here, we report that HBV leads to liver fibrosis and hepatocarcinogenesis through miR-30e targeting P4HA2. HBV transgenic mouse was treated by CCl to generate a model of liver fibrosis. A crucial enzyme catalyzing collagen formation, prolyl 4-hydroxylase subunit α2 (P4HA2) was evaluated by immunohistochemistry, western blotting or quantitative reverse transcription-PCR analysis. The function of HBV-modulated P4HA2 in hepatoma cell growth in vitro and in vivo was analyzed by EdU, MTT, colony-forming assay and animal transplantation assay. HBV transgenic mice exhibited more collagen deposition in liver after intraperitoneal injection of CCl. P4HA2 was dramatically augmented in liver samples of HBV transgenic mice, clinical liver cirrhosis and liver cancer patients. Mechanistically, HBx was capable of inducing P4HA2 through suppressing miR-30e, in which miR-30e could target P4HA2 mRNA 3' untranslated region in liver cancer cells. HBx inhibited the miR-30e expression through increasing methylation of CpG islands in its promoter mediated by EZH2-formed complexes. Functionally, HBx-elevated P4HA2 enhanced the collagen deposition in the liver in vivo and in vitro, leading to liver fibrosis and liver cancer progression. In conclusion, HBx promotes the development of liver fibrosis and hepatocellular carcinoma through miR-30e targeting P4HA2 mRNA. We provide novel perspective on how HBx induces liver fibrosis.
乙型肝炎病毒（HBV）诱导的肝坏死在肝硬化进展中起很大作用。然而，关于乙型肝炎病毒X蛋白（HBx）是否对肝纤维化有影响，人们了解得较少。在此，我们报告HBV通过miR-30e靶向P4HA2导致肝纤维化和肝癌发生。用四氯化碳（CCl）处理HBV转基因小鼠以建立肝纤维化模型。通过免疫组织化学、蛋白质印迹或定量逆转录 - PCR分析评估催化胶原蛋白形成的关键酶脯氨酰4 - 羟化酶亚基α2（P4HA2）。通过EdU、MTT、集落形成试验和动物移植试验分析HBV调节的P4HA2在体外和体内肝癌细胞生长中的作用。腹腔注射CCl后，HBV转基因小鼠肝脏中出现更多的胶原沉积。P4HA2在HBV转基因小鼠、临床肝硬化和肝癌患者的肝脏样本中显著增加。机制上，HBx能够通过抑制miR-30e诱导P4HA2，其中miR-30e可靶向肝癌细胞中P4HA2 mRNA的3'非翻译区。HBx通过增加由EZH2形成的复合物介导的其启动子中CpG岛的甲基化来抑制miR-30e表达。功能上，HBx升高的P4HA2在体内和体外增强了肝脏中的胶原沉积，导致肝纤维化和肝癌进展。总之，HBx通过miR-30e靶向P4HA2 mRNA促进肝纤维化和肝细胞癌的发展。我们为HBx如何诱导肝纤维化提供了新的视角。
