title: A combined approach identifies three mRNAs that are down-regulated by microRNA-29b and promote invasion ability in the breast cancer cell line MCF-7.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) are short noncoding RNAs that regulate gene expression by targeting mRNAs. Our previous study found that miR-29b strongly regulates the migration and invasion of breast cancer cells. Here, we aimed to identify the mRNAs targeted by miR-29b.
  
  
  METHODS
  We used microarray experiments in conjunction with computational methods to identify the mRNAs that were most susceptible to miR-29b-mediated repression. We further confirmed the activities of three target genes, C1QTNF6, SPARC, and COL4A2, by luciferase reporter analyses and invasion assays.
  
  
  RESULTS
  We evaluated the impact of miR-29b on global mRNA expression in MCF-7 human breast cancer cells through microarray analysis and further analyzed four genes that were at least twofold down-regulated and predicted as miR-29b targets by at least two of the four widely used miRNA target prediction algorithms. We also analyzed one mRNA that was down-regulated by 1.8-fold but was predicted to have significant interactions with miR-29b in pathway analysis and was predicted as a miR-29b target by all four algorithms. Luciferase reporter and invasion assays revealed that C1QTNF6, SPARC, and COL4A2 were targeted by miR-29b and that the degradation of any one of these mRNAs could promote invasion in MCF-7 cells.
  
  
  CONCLUSIONS
  C1QTNF6, SPARC, and COL4A2 are targeted by miR-29b, and the down-regulation of these three mRNAs can contribute to the invasion ability of MCF-7 cells.
authors.affiliation: Center for Translational Medicine and Jiangsu Key Laboratory of Molecular Medicine, School of Medicine, Nanjing University, Nanjing, Jiangsu, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: Gao
authors.forename: Jun-Long
authors.initials: JL
authors.lastname: Zhuang
authors.forename: Chao
authors.initials: C
authors.lastname: Ding
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
mesh_terms: D020413:3' Untranslated Regions; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D045744:Cell Line, Tumor; D003094:Collagen; D024141:Collagen Type IV / Q000235:genetics; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000235:genetics*; D009361:Neoplasm Invasiveness; D015676:Osteonectin / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics*; D048069:Tumor Necrosis Factors / Q000235:genetics; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; C561455:C1qTNF6 protein, human; C502625:COL4A2 protein, human; D024141:Collagen Type IV; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D015676:Osteonectin; D012333:RNA, Messenger; D048069:Tumor Necrosis Factors; D003094:Collagen