title: [miR-145 inhibits lung adenocarcinoma stem cells proliferation by targeting OCT4 gene].
abstract: OBJECTIVE
  MiR-145 functions as a protective miRNA identified in tumor tissues of lung adenocarcinoma patients. The aim of this study is to investigate the relationship between miR-145 and proliferation of lung cancer stem cells and involved molecular mechanisms in human lung adenocarcinoma A549 cell line.
  
  
  METHODS
  MicroRNA microarray technology was conducted to compare miRNA signature between tumor and adjacent normal tissue of lung adenocarcinoma. The potential target gene of miR-145 was predicted by online bioinformatic softwares. Pre-miR-145 mimics and anti-miR-145 inhibitor were transfected into A549 cell line by lipofectamine 2000. miR-145 expression in each group was detected by real time PCR. The OCT4 protein level was analyzed by Western blot. The predicted miR-145 binding site in OCT4 3'-untranslated region (UTR) was validated by dual-luciferase reporter gene assay. CCK-8 assay was employed to observe the proliferation activity of A549 cells. The ratio of CD133 positive cells in each group was analyzed by flow cytometry.
  
  
  RESULTS
  miR-145 expression was significantly down-regulated in lung adenocarcinoma compared with ajacent normal tissue. OCT4 is a potential target gene of miR-145 predicted by miRanda. Compared with control group, miR-145 was significantly up-regulated and down-regulated in the pre-miR-145 mimics and anti-miR-145 inhibitor groups respectively. Overexpression of miR-145 inhibited the proliferation of A549 cells. Both the OCT4 protein level and CD133 positive ratio were remarkably decreased in the pre-miR-145 mimics group, whereas significantly increased in the anti-miR-145 inhibitor group. Dual-luciferase reporter gene assay validated the predicted miR-145 binding site of OCT4 3'UTR.
  
  
  CONCLUSIONS
  MiR-145 can inhibit the proliferation of lung cancer stem cells in A549 cell line via down-regulating OCT4 expression. MiR-145 is a potential protective miRNA of lung cancer.
authors.affiliation: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital of Jiangsu Province, Nanjing, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wu
authors.forename: Dongjie
authors.initials: D
authors.lastname: Feng
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.forename: Rong
authors.initials: R
authors.lastname: Yin
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
mesh_terms: D000071916:AC133 Antigen; D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D015703:Antigens, CD / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019295:Computational Biology; D015536:Down-Regulation / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D050814:Octamer Transcription Factor-3 / Q000235:genetics* / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D016133:Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism* / Q000473:pathology*
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C000606023:PROM1 protein, human; D010455:Peptides