title: Hepatitis B virus-human chimeric transcript HBx-LINE1 promotes hepatic injury via sequestering cellular microRNA-122.
abstract: OBJECTIVE
  Chronic hepatitis B virus (HBV) carriers have a high risk to develop hepatocellular carcinoma (HCC) but the underlying mechanism remains unclear. Recent studies suggest that viral-human hybrid RNA transcripts, which play a critical role in promoting HCC progression, may be the molecules responsible for the development of HCC in HBV infected patients. Here we determine whether HBx-LINE1, a hybrid RNA transcript of the human LINE1 and the HBV-encoded X gene generated in tumor cells of HBV-positive HCC, can serve as a molecular sponge for sequestering miR-122 and promoting liver cell abnormal mitosis and mouse hepatic injury.
  
  
  METHODS
  Paired tumor and distal normal liver tissue specimens, as well as HBx-LINE1 overexpressing hepatic cells, were used to test the relationship between HBx-LINE1 and miR-122. Levels of HBx-LINE1 and miR-122 were assayed by qRT-PCR and Northern blot. HBx-LINE1-miR-122 binding was analyzed by luciferase reporter assay. Mouse hepatic injury was monitored by tissue staining and serum aspartate transaminase, alanine aminotransferase and total bilirubin measurement.
  
  
  RESULTS
  HBx-LINE1 in HBV-positive HCC tissues was inversely correlated with miR-122. Each HBx-LINE1 consists of six miR-122-binding sites, and forced expression of HBx-LINE1 effectively depleted cellular miR-122, promoting hepatic cell epithelial-mesenchymal transition (EMT)-like changes, including β-catenin signaling activation, E-cadherin reduction and cell migration enhancement. Mice administered with HBx-LINE1 display a significant mouse liver cell abnormal mitosis and hepatic injury. However, all these effects of HBx-LINE1 are completely abolished by miR-122.
  
  
  CONCLUSIONS
  Our finding illustrates a previously uncharacterized miR-122-sequestering mechanism by which HBx-LINE1 promotes hepatic cell EMT-like changes and mouse liver injury.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Yanbo
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of General Surgery, the Affiliated Gulou Hospital of Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Comprehensive Cancer Center, the Affiliated Gulou Hospital of Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Gastroenterology, the Affiliated Gulou Hospital of Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Diao
authors.affiliation: Department of Hepatobiliary Surgery, the Affiliated Gulou Hospital of Nanjing University, Nanjing, Jiangsu 210093, China. Electronic address: yitaoding@hotmail.com.
authors.forename: Yitao
authors.initials: Y
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China. Electronic address: xichen@nju.edu.cn.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China. Electronic address: cyzhang@nju.edu.cn.
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China. Electronic address: kzen@nju.edu.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Zen
mesh_terms: D000818:Animals; D015703:Antigens, CD; D015820:Cadherins / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology / Q000821:virology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics / Q000502:physiology; D019694:Hepatitis B, Chronic / Q000378:metabolism / Q000473:pathology / Q000821:virology; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology / Q000821:virology; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology / Q000821:virology; D051379:Mice; D035683:MicroRNAs / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; C544354:Mirn122 microRNA, mouse; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein
keywords: HBV; HBx-LINE1; HCC; miR-122; miRNA sponge