title: microRNA-145 promotes differentiation in human urothelial carcinoma through down-regulation of syndecan-1.
abstract: BACKGROUND
  A new molecular marker of carcinoma in the urinary bladder is needed as a diagnostic tool or as a therapeutic target. Potential markers include microRNAs (miRNAs), which are short, low molecular weight RNAs 19-24 nt long that regulate genes associated with cell proliferation, differentiation, and development in various cancers. In this study, we investigated the molecular mechanisms by which miR-145 promotes survival of urothelial carcinoma cells and differentiation into multiple lineages. We found miR-145 to regulate expression of syndecan-1, a heparin sulfate proteoglycan.
  
  
  METHODS
  Cell proliferation in the human urothelial carcinoma cell lines T24 and KU7 was assessed by MTS assay. Cellular senescence and apoptosis were measured by senescence-associated β-galactosidase (SA-β-gal) and TUNEL assay, respectively. Quantitative RT-PCR was used to measure mRNA expression of various genes, including syndecan-1, stem cell factors, and markers of differentiation into squamous, glandular, or neuroendocrine cells.
  
  
  RESULTS
  Overexpression of miR-145 induced cell senescence, and thus significantly inhibited cell proliferation in T24 and KU7 cells. Syndecan-1 expression diminished, whereas stem cell markers such as SOX2, NANOG, OCT4, and E2F3 increased. miR-145 also up-regulated markers of differentiation into squamous (p63, TP63, and CK5), glandular (MUC-1, MUC-2, and MUC-5 AC), and neuroendocrine cells (NSE and UCHL-1). Finally, expression of miR-145 was down-regulated in high-grade urothelial carcinomas, but not in low-grade tumors.
  
  
  CONCLUSIONS
  Results indicate that miR-145 suppresses syndecan-1 and, by this mechanism, up-regulates stem cell factors and induces cell senescence and differentiation. We propose that miR-145 may confer stem cell-like properties on urothelial carcinoma cells and thus facilitate differentiation into multiple cell types.
authors.affiliation: Department of Pathology, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan. fujiit@naramed-u.ac.jp.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Pathology, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan. keijishi@naramed-u.ac.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Department of Pathology, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan. tatsumi3@naramed-u.ac.jp.|Department of Urology, Nara Medical University School of Medicine, Nara, Japan. tatsumi3@naramed-u.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tatsumi
authors.affiliation: Department of Diagnostic Pathology, Nara Medical University School of Medicine, Nara, Japan. kpathol@naramed-u.ac.jp.
authors.forename: Kinta
authors.initials: K
authors.lastname: Hatakeyama
authors.affiliation: Department of Diagnostic Pathology, Nara Medical University School of Medicine, Nara, Japan. ohbayashi@naramed-u.ac.jp.
authors.forename: Chiho
authors.initials: C
authors.lastname: Obayashi
authors.affiliation: Department of Urology, Nara Medical University School of Medicine, Nara, Japan. kiyokun@naramed-u.ac.jp.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fujimoto
authors.affiliation: Department of Pathology, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan. nkonishi@naramed-u.ac.jp.
authors.forename: Noboru
authors.initials: N
authors.lastname: Konishi
mesh_terms: D014408:Biomarkers, Tumor; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D050699:E2F3 Transcription Factor / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D000071317:Nanog Homeobox Protein; D060787:Neoplasm Grading; D050814:Octamer Transcription Factor-3 / Q000235:genetics; D034622:RNA Interference; D055748:SOXB1 Transcription Factors / Q000235:genetics; D053668:Syndecan-1 / Q000235:genetics*; D014523:Urethral Neoplasms / Q000235:genetics* / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D050699:E2F3 Transcription Factor; C098319:E2F3 protein, human; D018398:Homeodomain Proteins; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D053668:Syndecan-1