Expression patterns of miR-21 and miR-146 in ulcerative colitis: implications for disease progression and therapeutic strategies.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD), where dysregulated microRNAs (miRNAs) may play a role in the immune imbalance and injury to the mucosa. miR-21 and miR-146 have been associated with inflammatory signaling pathways. OBJECTIVE: The aim of this study was to evaluate the expression levels of miR-21 and miR-146 in blood and colonic tissue of patients newly diagnosed with Ulcerative Colitis (UC) compared to healthy controls. METHODS: A case-control study was performed from January to October 2025. Patients who have recently been diagnosed with UC. The age range of the study subjects was 15-65 years and they were recruited at the time of diagnosis from gastroenterology/endoscopy services inxx and from collaborating clinics and healthy individuals as controls. Total RNA extracted from peripheral blood and colonic tissue, and expression of miR-21 and miR-146 levels were quantified by qRT-PCR, Relative miRNA expression levels were calculated by the 2^-ΔCt method after normalization with the endogenous reference gene. The relative expression levels was calculated to the control groups. RESULTS: Expression of miR-21 and miR-146 in blood and tissue was significantly lower in patients than in the controls. CONCLUSIONS: The new findings were that miR-21 and miR-146 were down-regulated in blood and much more strongly suppressed in colonic tissue in newly diagnosed UC. The results further confirm miR-21 and miR-146 as potential biomarker candidates for UC characterization, and as potential starting points for miRNA-based therapeutic approaches. These patterns should be confirmed in larger cohorts of patients and correlated to disease severity, extent and treatment response using formal inferential statistics in future studies.