title: MiRNA-15a mediates cell cycle arrest and potentiates apoptosis in breast cancer cells by targeting synuclein-γ.
abstract: BACKGROUND
  Recent studies have indicated that microRNA-15a (miR-15a) is dysregulated in breast cancer (BC). We aimed to evaluate the expression of miR-15a in BC tissues and corresponding para-carcinoma tissues. We also focused on effects of miR-15a on cellular behavior of MDA-MB-231 and expression of its target gene synuclein-γ (SNCG).
  
  
  METHODS
  The expression levels of miR-15a were analysed in BC formalin fixed paraffin embedded (FFPE) tissues by microarray and quantitative real-time PCR. CCK-8 assays, cell cycle and apoptosis assays were used to explore the potential functions of miR-15a in MDA-MB-231 human BC cells. A luciferase reporter assay confirmed direct targets.
  
  
  RESULTS
  Downregulation of miR-15a was detected in most primary BCs. Ectopic expression of miR-15a promoted proliferation and suppressed apoptosis in vivo. Further studies indicated that miR-15a may directly interact with the 3'-untranslated region (3'-UTR) of SNCG mRNA, downregulating its mRNA and protein expression levels. SNCG expression was negatively correlated with miR-15a expression.
  
  
  CONCLUSIONS
  MiR-15a has a critical role in mediating cell cycle arrest and promoting cell apoptosis of BC, probably by directly targeting SNCG. Thus, it may be involved in development and progression of BC.
authors.affiliation: Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, China E-mail : zhouxinwhu@163.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Xie
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Guo-Lian
authors.initials: GL
authors.lastname: Pang
authors.forename: Wan
authors.initials: W
authors.lastname: Luo
authors.forename: Jian-Cheng
authors.initials: JC
authors.lastname: Tu
authors.forename: Fang
authors.initials: F
authors.lastname: Zheng
authors.forename: Song-Mei
authors.initials: SM
authors.lastname: Liu
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.forename: Jian-Kun
authors.initials: JK
authors.lastname: Zhang
authors.forename: Xian-Yong
authors.initials: XY
authors.lastname: Luo
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D017209:Apoptosis / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D015536:Down-Regulation; D005260:Female; D059585:G1 Phase Cell Cycle Checkpoints / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D051845:gamma-Synuclein / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; C505361:MIRN15 microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; C104249:SNCG protein, human; D051845:gamma-Synuclein