hsa-miR-93 regulates MUCIN family gene expression via WNT/β-catenin pathway in intrahepatic stone disease.

Background: Mucin plays an essential role in the intrahepatic stone formation, but the mechanism of mucin regulation is unclear.

Objective: To investigate the potential implication of miR-93 and WNT pathway in the regulation of intrahepatic bile duct mucin expression.

Methods: Thirty patients with or without intrahepatic bile duct stones are involved; Reverse-transcription polymerase chain reaction was performed to evaluate the expression of MUC3, MUC4, MUC5B, MUC5AC mRNA and miR-93 levels. miR-NC or miR-93 mimics was transfected into intrahepatic biliary epithelial cells. Then mucins and Wnt pathway proteins were detected by the immunoblotting, and the target gene TCF7 were validated using the dual luciferase assay. β-catenin, wnt4, and mucins were an immunohistochemical stain of the intrahepatic biliary epithelial tissues.

Results: The expression levels of MUC3, MUC4, MUC5B, and MUC5AC in patients with intrahepatic bile duct stones are higher than control, as well as Wnt pathway proteins (especially β-catenin and wnt4). Mucins levels increased in wnt4, wnt5a or SB216763-treated HIBECs, and reduced by miR-93 mimics transfection. miR-93 directly targeted TCF7 and repressed Wnt pathway protein expression, which reversed the upregulation of mucin levels induced by wnt4 or wnt5a, but not SB216763.

Conclusion: These results suggest a new potential mechanism in intrahepatic stones, regulating by miR-93/TCF7, non-canonical Wnt pathway, and mucins.