title: Involvement of microRNA-718, a new regulator of EGR3, in regulation of malignant phenotype of HCC cells.
abstract: OBJECTIVE
  Hepatocellular carcinoma (HCC) is still one of the most common death-related malignancies worldwide. Because the way onset and progression are hidden most, HCC diagnoses are made at an advanced stage, when they are unsuitable for surgical resection. MicroRNAs are a class of small non-coding RNAs, participating in many aspects of cancers. In this study, we tried to establish the role of microRNA-718 (miR-718) in the malignant phenotype of HCC cells and its possible role in HCC diagnosis.
  
  
  METHODS
  Here we first used a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, Transwell migration and invasion assays, and colony formation assay to evaluate the impact of miR-718 on the malignant phenotypes of HCC cells. Then, we used bioinformatic methods to predict the target gene of miR-718 and used green fluorescence protein (GFP) reporter assay, Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR) to validate the regulation relationship. Finally, we determined the role of the target gene in the HCC phenotype.
  
  
  RESULTS
  We found that the expression of miR-718 was significantly reduced in various HCC cell lines and HCC tissues. Re-expression of miR-718 significantly reduced the cellular viability and colony formation ability as well as inhibited the migration and invasion abilities of HCC cell lines. Early growth response protein 3 (EGR3) is a direct target of miR-718 and is negatively regulated by miR-718. EGR3 could increase the viability and proliferation of HCC cells, and promot the migration and invasion of HCC cells.
  
  
  CONCLUSIONS
  miR-718 acts as a tumor suppressive microRNA in HCC via regulating the expression of EGR3, which may provide a new diagnostic marker and treatment target for HCC.
authors.affiliation: Clinical Laboratory of Taishan Sanatorium of Shandong Province, Tai'an 271001, China.
authors.forename: Zhong-Dong
authors.initials: ZD
authors.lastname: Wang
authors.affiliation: Interventional Radiology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, China.
authors.forename: Fan-Yong
authors.initials: FY
authors.lastname: Qu
authors.affiliation: Center of Health Examination, Affiliated Hospital of Taishan Medical University, Tai'an 271001, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Center of Health Examination, Affiliated Hospital of Taishan Medical University, Tai'an 271001, China.
authors.forename: Zhang-Shen
authors.initials: ZS
authors.lastname: Ran
authors.affiliation: Department of Oncology, Affiliated Hospital of Taishan Medical University, Tai'an 271001, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Liu
authors.affiliation: Department of Basic Medicine, Taishan Medical University, Tai'an 271001, China.
authors.forename: Hai-Dong
authors.initials: HD
authors.lastname: Zhang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D019295:Computational Biology; D051776:Early Growth Response Protein 3 / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D035683:MicroRNAs / Q000502:physiology*; D009361:Neoplasm Invasiveness; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism
chemical_list: C079945:EGR3 protein, human; C000589574:MIRN718 microRNA, human; D035683:MicroRNAs; D051776:Early Growth Response Protein 3; D049452:Green Fluorescent Proteins
keywords: miR-718; MicroRNA; Early growth response protein 3 (EGR3); Hepatocellular carcinoma (HCC); Malignant phenotype