title: Tumor suppressor miR-22 suppresses lung cancer cell progression through post-transcriptional regulation of ErbB3.
abstract: BACKGROUND
  Development of efficient therapies of lung cancer and deep understanding of their anti-tumor mechanism are very important. The aim of the present study is to investigate the therapeutic effect of microRNA-22 (miR-22) on lung cancer using in vitro and in vivo methods.
  
  
  METHODS
  Expression level of miR-22 in lung cancer specimens and relative normal tissues was detected by microRNA-specific quantitative real-time PCR (Q-PCR). Invasion assay, cell counting kit-8 assay, and Annexin V/7-AAD analysis were performed to test the invasion and proliferation of lung cancer cell after transfection. The effect of miR-22 on lung cancer in vivo was validated by murine xenograft model.
  
  
  RESULTS
  Q-PCR detection of miR-22 in clinical samples showed that the relative expression level of miR-22 in lung cancer tissues and lung cancer cell lines was lower than that in normal tissues. Transfection of miR-22 expression plasmids could significantly inhibit the increased cell numbers and invasion of A549 and H1299 lung cancer cell lines. Furthermore, miR-22 was demonstrated to inhibit the expression of ErbB3 through post-transcriptional regulation via binding to ErbB3 3'-UTR. Co-transfection of ErbB3 expression plasmid could promote the proliferation and invasion of A549 and H1299. In vivo experiments using nude mice demonstrated that over-expression of miR-22 could significantly decrease the volume and weight of tumors.
  
  
  CONCLUSIONS
  miR-22 exhibited excellent anti-lung cancer activity in vitro and in vivo, and post-transcriptional regulation of ErbB3 might be a potential mechanism.
authors.affiliation: Key Laboratory of Biological Science and Technology, Chongqing University, Ministry of Education, Bioengineering College of Chongqing University, Chongqing 400044, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Ling
authors.forename: Gui-Xue
authors.initials: GX
authors.lastname: Wang
authors.forename: Guang
authors.initials: G
authors.lastname: Long
authors.forename: Ju-Hui
authors.initials: JH
authors.lastname: Qiu
authors.forename: Zhong-Lei
authors.initials: ZL
authors.lastname: Hu
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D045744:Cell Line, Tumor; D018450:Disease Progression; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D020893:Receptor, ErbB-3 / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D047368:Tumor Burden / Q000235:genetics; D023041:Xenograft Model Antitumor Assays / Q000379:methods
chemical_list: D020413:3' Untranslated Regions; C548375:MIRN22 microRNA, human; D035683:MicroRNAs; D020893:Receptor, ErbB-3