MicroRNA‑7‑5p regulates the expression of TFF3 in inflammatory bowel disease.

Trefoil factor 3 (TFF3) serves an important role in intestinal mucosal damage and healing, and contributes to the pathogenesis and treatment of inflammatory bowel disease (IBD). The aim of the present study was to determine the association between TFF3 and microRNA‑7‑5p (miR‑7‑5p) in IBD. Tissue immunohistochemistry was applied to evaluate the relative expression of TFF3, and reverse transcription‑quantitative polymerase chain reaction was performed to determine the expression of miR‑7‑5p in lesional tissue obtained from patients with IBD and healthy control tissues. A dual‑luciferase reporter assay was used to investigate whether TFF3 was a target of miR‑7‑5p, and western blotting was performed to determine the expression of TFF3 when miR‑7‑5p was overexpressed or suppressed. The protein expression levels of TFF3 were decreased and miR‑7‑5p was overexpressed in the lesional tissue of patients with IBD compared with in healthy control tissues. TFF3 was identified as a target of miR‑7‑5p, and TFF3 protein expression was negatively regulated by miR‑7‑5p in human colonic epithelial LS174T cells. The present study demonstrated a negative association between the expression of miR‑7‑5p and TFF3 in IBD lesional tissues and normal tissues. In conclusion, TFF3 was identified as a novel target of miR‑7‑5p and miR‑7‑5p may serve as a promising therapeutic target for IBD.