Elevated miRNA Inversely Correlates with E-cadherin Gene Expression in Tissue Biopsies from Crohn Disease Patients in contrast to Ulcerative Colitis Patients.

Inflammatory bowel disease (IBD) comprises ulcerative colitis (UC) and Crohn disease (CD). Similar symptoms, but different treatment procedures for both diseases require precise diagnosis. MicroRNAs (miRNAs) are major posttranscriptional players that regulate the expression of genes during the inflammation and thus could be appropriate biomarkers for differentiation between UC and CD. For this purpose, we analyzed the expression ofmiR-21-3p,miR-31-3p,miR-125b-1-3p,miR-146a-3p,miR-155-5p, andE-cadherin(CDH1)genes associated with IBD, in 67 tissue samples: 28 inflamed mucosa samples (n=16UC,n=12CD), 28 adjacent normal colonic mucosa (n=16UC,n=12CD), and 11 normal mucosa from healthy patients using reverse transcription real-time RT-PCR. We found all analyzed miRNAs were significantly overexpressed in UC tissue as compared to adjacent normal tissue of patients with UC, as well as to normal mucosa from healthy controls. Four miRNAs (exceptmiR-125b-1-3p) were significantly upregulated in CD lesions as compared to adjacent normal tissue of patients with CD, and four miRNAs, exceptmiR-146a-3p, were significantly higher in CD samples compared to normal mucosa from healthy individuals. In the CD group, we found an inverse correlation betweenmiR-155-5pormiR-146a-3pexpressions andCDH1expression in inflamed mucosa. This type of correlation was also detected formiR-213pin adjacent normal tissue andCDH1in inflamed mucosa, as well as betweenmiR-155-5pandCDH1in adjacent normal tissue. Elevated miRNA expression is characteristic for IBD-mediated inflammation process and inversely correlated withCDH1gene expression, which suggest involvement of epithelial to mesenchymal transition (EMT) in IBD development.