title: miR-17-5p promotes human breast cancer cell migration and invasion through suppression of HBP1.
abstract: MicroRNAs have been implicated in regulating diverse cellular pathways. Emerging evidence indicate that the miR-17-92 cluster may have a causal role in breast cancer tumorigenesis as a novel class of oncogenes, but the role of these miRNAs in breast cancer invasion and migration remains unexplored. The aims of this study were to verify the effect of miR-17-5p (an important member of the miR-17-92 cluster) on the invasive and migratory ability of breast cancer cells. The matching of miR-17-5p and HMG box-containing protein 1 (HBP1) was predicted by TargetScan and confirmed by DNA constructs and luciferase target assay. The expression levels of miR-17-5p and its candidate target-HBP1 in MCF7 and MDA-MB-231 breast cancer cells were measured by real-time PCR and western blotting. Effects of miR-17-5p in cell cycle progression, proliferation, invasion and migration were evaluated by flow cytometry assay, 3-(4,-dimethy -lthiazol-2-yl)-2,-diphenyl -tetrazoliumbromide assay, soft-agar colony formation assay, and transwell invasive and migratory assay, respectively. The results showed that miR-17-5p was highly expressed in high-invasive MDA-MB-231 breast cancer cells but not in low-invasive MCF-7 breast cancer cells. Over-expression of miR-17-5p in MCF-7 cells rendered them the invasive and migratory abilities by targeting HBP1/β-catenin pathway. On the other hand, down-regulation of endogenous miR-17-5p suppressed the migration and invasion of MDA-MB-231 cells in vitro. These findings suggest that miR-17-5p plays an important role in breast cancer cell invasion and migration by suppressing HBP1 and subsequent activation of Wnt/β-catenin.
authors.affiliation: Institute of Basic Medical Sciences and School of Basic Medicine, Center of Excellence in Tissue Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, 5# Dongdansantiao, Beijing, People's Republic of China.
authors.forename: Hongling
authors.initials: H
authors.lastname: Li
authors.forename: Chunjing
authors.initials: C
authors.lastname: Bian
authors.forename: Lianming
authors.initials: L
authors.lastname: Liao
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Robert Chunhua
authors.initials: RC
authors.lastname: Zhao
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D006609:High Mobility Group Proteins / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis*; D009361:Neoplasm Invasiveness; D012097:Repressor Proteins / Q000096:biosynthesis / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D051153:Wnt Proteins / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: C486328:HBP1 protein, human; D006609:High Mobility Group Proteins; C524941:MIRN17 microRNA, human; D035683:MicroRNAs; D012097:Repressor Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D051153:Wnt Proteins; D051176:beta Catenin; C022616:thiazolyl blue