title: Epigenetic modification of MiR-429 promotes liver tumour-initiating cell properties by targeting Rb binding protein 4.
abstract: OBJECTIVE
  Liver tumour-initiating cells (T-ICs) are critical for hepatocarcinogenesis. However, the underlying mechanism regulating the function of liver T-ICs remains unclear.
  
  
  METHODS
  Tissue microarrays containing 242 hepatocellular carcinoma (HCC) samples were used for prognostic analysis. Magnetically activated cell sorting was used to isolate epithelial cell adhesion molecule (EPCAM)-positive cells. The gene expressions affected by miR-429 were determined by arrays. Co-immunoprecipitation was used to study interactions among retinoblastoma protein (RB1), Rb binding protein 4 (RBBP4) and E2F transcription factor 1 (E2F1). The DNA methylation status in CpG islands was detected by quantitative methylation analysis. miRNAs in microvesicles were isolated by a syringe filter system.
  
  
  RESULTS
  The significant prognosis factor miR-429 was upregulated in HCC tissues and also in primary liver T-ICs isolated from clinical samples. The enrichment of miR-429 in EPCAM+ T-ICs contributed to hepatocyte self-renewal, malignant proliferation, chemoresistance and tumorigenicity. A novel functional axis involving miR-429, RBBP4, E2F1 and POU class 5 homeobox 1 (POU5F1 or OCT4) governing the regulation of liver EPCAM+ T-ICs was established in vitro and in vivo. The molecular mechanism regulating miR-429 expression, involving four abnormal hypomethylated sites upstream of the miR-200b/miR-200a/miR-429 cluster, was first defined in both EPCAM+ liver T-ICs and very early-stage HCC tissues. miR-429 secreted by high-expressing cells has the potential to become a proactive signalling molecule to mediate intercellular communication.
  
  
  CONCLUSIONS
  Epigenetic modification of miR-429 can manipulate liver T-ICs by targeting the RBBP4/E2F1/OCT4 axis. This miRNA might be targeted to inactivate T-ICs, thus providing a novel strategy for HCC prevention and treatment.
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Zhang
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Yang
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Miyang
authors.initials: M
authors.lastname: LiuGao
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Wang
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Yexiong
authors.initials: Y
authors.lastname: Tan
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Jianling
authors.initials: J
authors.lastname: Fan
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Chang
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fu
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
authors.forename: Caiyang
authors.initials: C
authors.lastname: Chen
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Yingcheng
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Bioinformatics Division, TNLIST/Department of Automation, Tsinghua University, Beijing, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Gu
authors.affiliation: Bioinformatics Division, TNLIST/Department of Automation, Tsinghua University, Beijing, China.
authors.forename: Dingming
authors.initials: D
authors.lastname: Wu
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Linna
authors.initials: L
authors.lastname: Guo
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Cao
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
authors.forename: Hengyu
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Epidemiology, Second Military Medical University, Shanghai, China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Cao
authors.affiliation: Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Mengchao
authors.initials: M
authors.lastname: Wu
authors.affiliation: Bioinformatics Division, TNLIST/Department of Automation, Tsinghua University, Beijing, China.
authors.forename: Michael Q
authors.initials: MQ
authors.lastname: Zhang
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China National Laboratory for Oncogenes and Related Genes, Cancer Institute, Ruijing Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Hongyang
authors.initials: H
authors.lastname: Wang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology*; D044127:Epigenesis, Genetic; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology*; D035683:MicroRNAs / Q000235:genetics*; D014411:Neoplastic Stem Cells; D011379:Prognosis; D016160:Retinoblastoma Protein / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: C546363:MIRN429 microRNA, human; D035683:MicroRNAs; D016160:Retinoblastoma Protein
keywords: Hepatocellular Carcinoma; Signal Transduction; Stem Cells