title: miR-200b suppresses cell growth, migration and invasion by targeting Notch1 in nasopharyngeal carcinoma.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) are a class of small noncoding RNA molecules that play important roles in carcinogenesis and tumor progression. We investigated the roles and mechanisms of miR-200b in human nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  We used quantitative real-time polymerase chain reaction (qRT-PCR) analyses to measure levels of miR-200b and Notch1 in NPC specimens and cell lines. Human NPC cell lines stably expressing miR-200b or control were used to analyze the tumour-suppressive effect of miR-200b. Luciferase reporter assays were used to determine the association between miR-200b and the Notch1 3' untranslated region.
  
  
  RESULTS
  We found that miR-200b is significantly downregulated in NPC tissues and cell lines. Gain-of-function and loss-of-function studies demonstrated that miR-200b suppresses NPC cell growth, migration and invasion in vitro. Importantly, overexpression of miR-200b effectively repressed tumor growth in nude mouse models. Integrated analysis identified Notch1 as a direct and functional target of miR-200b. Overexpression of Notch1 reversed the inhibitory effect of miR-200b on NPC cell growth and invasion.
  
  
  CONCLUSIONS
  These results indicate that miR-200b exerts tumor-suppressive effects in NPC carcinogenesis through the suppression of Notch1 expression and suggest a therapeutic application of miR-200b in NPC.
authors.affiliation: Department of Otorhinolaryngology, Shanghai Xuhui Center Hospital, Shanghai, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.forename: Weichun
authors.initials: W
authors.lastname: Ni
authors.forename: Ke
authors.initials: K
authors.lastname: Lei
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D002277:Carcinoma; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000502:physiology*; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000473:pathology*; D051881:Receptor, Notch1 / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; C533896:MIRN200 microRNA, human; D035683:MicroRNAs; C497761:NOTCH1 protein, human; D051881:Receptor, Notch1