title: miR-20b, miR-98, miR-125b-1*, and let-7e* as new potential diagnostic biomarkers in ulcerative colitis.
abstract: OBJECTIVE
  To use microarray-based miRNA profiling of colonic mucosal biopsies from patients with ulcerative colitis (UC), Crohn's disease (CD), and controls in order to identify new potential miRNA biomarkers in inflammatory bowel disease.
  
  
  METHODS
  Colonic mucosal pinch biopsies from the descending part were obtained endoscopically from patients with active UC or CD, quiescent UC or CD, as well as healthy controls. Total RNA was isolated and miRNA expression assessed using the miRNA microarray Geniom Biochip miRNA Homo sapiens (Febit GmbH, Heidelberg, Germany). Data analysis was carried out by principal component analysis and projection to latent structure-discriminant analysis using the SIMCA-P+12 software package (Umetrics, Umea, Sweden). The microarray data were subsequently validated by quantitative real-time polymerase chain reaction (qPCR) performed on colonic tissue samples from active UC patients (n = 20), patients with quiescent UC (n = 19), and healthy controls (n = 20). The qPCR results were analyzed with Mann-Whitney U test. In silico prediction analysis were performed to identify potential miRNA target genes and the predicted miRNA targets were then compared with all UC associated susceptibility genes reported in the literature.
  
  
  RESULTS
  The colonic mucosal miRNA transcriptome differs significantly between UC and controls, UC and CD, as well as between UC patients with mucosal inflammation and those without. However, no clear differences in the transcriptome of patients with CD and controls were found. The miRNAs with the strongest differential power were identified (miR-20b, miR-99a, miR-203, miR-26b, and miR-98) and found to be up-regulated more than a 10-fold in active UC as compared to quiescent UC, CD, and controls. Two miRNAs, miR-125b-1* and let-7e*, were up-regulated more than 5-fold in quiescent UC compared to active UC, CD, and controls. Four of the seven miRNAs (miR-20b, miR-98, miR-125b-1*, and let-7e*) were validated by qPCR and found to be specifically upregulated in patients with UC. Using in silico analysis we found several predicted pro-inflammatory target genes involved in various pathways, such as mitogen-activated protein kinase and cytokine signaling, which are both key signaling pathways in UC.
  
  
  CONCLUSIONS
  The present study provides the first evidence that miR-20b, miR-98, miR-125b-1*, and let-7e* are deregulated in patients with UC. The level of these miRNAs may serve as new potential biomarkers for this chronic disease.
authors.affiliation: Department of Gastroenterology, Medical Section, Herlev Hospital, University of Copenhagen, DK-2730 Herlev, Denmark. mehmet.coskun@regionh.dk
authors.forename: Mehmet
authors.initials: M
authors.lastname: Coskun
authors.forename: Jacob Tveiten
authors.initials: JT
authors.lastname: Bjerrum
authors.forename: Jakob Benedict
authors.initials: JB
authors.lastname: Seidelin
authors.forename: Jesper Thorvald
authors.initials: JT
authors.lastname: Troelsen
authors.forename: Jørgen
authors.initials: J
authors.lastname: Olsen
authors.forename: Ole Haagen
authors.initials: OH
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000378:metabolism; D003424:Crohn Disease / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D020935:MAP Kinase Signaling System; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D012984:Software
chemical_list: D015415:Biomarkers; C531888:MIRN125 microRNA, human; C534451:MIRN20a microRNA, human; C546084:MIRN98 microRNA, human; D035683:MicroRNAs; C487931:mirnlet7 microRNA, human
keywords: Biomarker; Crohn’s disease; Diagnostics; Inflammatory bowel disease; MicroRNA; Microarray; Ulcerative colitis