title: MicroRNA-27a promotes proliferation and suppresses apoptosis by targeting PLK2 in laryngeal carcinoma.
abstract: BACKGROUND
  miRNA-27a has been confirmed as an important regulator in carcinogenesis and other pathological processes. Whether and how it plays a role in the laryngeal carcinoma is unknown.
  
  
  METHODS
  Mature miRNA-27a expression in laryngeal cancer was detected by qRT-PCR. Gain-of-function studies using mature miR-27a were performed to investigate cell proliferation and apoptosis in the Hep2 cells. In silico database analysis and luciferase reporter assay were applied to predict and validate the direct target, respectively. Loss-of-function assays were performed to investigate the functional significance of the miR-27a target gene. qRT-PCR and Western blot were used to evaluate mRNA and protein levels of the target, respectively.
  
  
  RESULTS
  miR-27a was significantly up-regulated in the laryngeal tumor tissues compared to the adjacent non-tumor tissues. In silico database analysis result revealed that PLK2 is a potential target of miR-27a. luciferase reporter assay result showed the direct inhibition of miR-27a on PLK2-3'UTR. In the cases with miR-27a up-regulation, PLK2 protein expression level was significantly lower in cancer tissues than that in the adjacent non-tumor tissues, which showed a negative correlation with miR-27a expression level. Both miR-27a and knockdown of PLK2 caused the increase of the cell viability and colony formation and inhibition of the late apoptosis in the Hep2 cell lines. Moreover, miR-27a but not PLK2 also repressed the early apoptosis in the Hep2 cells. Additionally, no alteration of the Hep2 cell cycle induced by miR-27a was detected.
  
  
  CONCLUSIONS
  miR-27a acts as an oncogene in laryngeal squamous cell carcinoma through down-regulation of PLK2 and may provide a novel clue into the potential mechanism of LSCC oncogenesis or serve as a useful biomarker in diagnosis and therapy in laryngeal cancer.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: Shuang
authors.initials: S
authors.lastname: Fu
authors.affiliation: Department of Medical Genetics, China Medical University, Shenyang 110001, People's Republic of China. qiuguangbin@163.com.
authors.forename: Guang-Bin
authors.initials: GB
authors.lastname: Qiu
authors.forename: Zhen-Ming
authors.initials: ZM
authors.lastname: Xu
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: Zhang
authors.forename: Sheng
authors.initials: S
authors.lastname: Chen
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.forename: Kai-Lai
authors.initials: KL
authors.lastname: Sun
authors.forename: Wei-Neng
authors.initials: WN
authors.lastname: Fu
mesh_terms: D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: C531388:MIRN27 microRNA, human; D035683:MicroRNAs; C496126:PLK2 protein, human; D017346:Protein Serine-Threonine Kinases