Expression profile of microRNA-200 family in cholangiocarcinoma arising from choledochal cyst.

BACKGROUND AND AIM: The risk of cholangiocarcinoma (cCC) arising from choledochal cyst (CC-CC) is imminent, if the latter not treated appropriately in time. Epithelial-to-mesenchymal transition (EMT) is considered a critical step for various solid cancers, which is regulated by the microRNA-200 (miR-200) family. The aim of this study was to assess the role of miR-200 family in the pathogenesis of CC-CC.

METHODS: Sixteen patients with CC-CC were enrolled and 254 patients with conventional cCC served as clinicopathologic controls. Fifty-four cCC were selected to compare the miR-200 family expression and immunohistochemical characteristics. Gain-and loss-of-function studies of miR-200 family were conducted using the cCC cell lines.

RESULTS: CC-CC were younger (P < 0.01), more female- predominated (P < 0.01), and rarely associated with lithiasis (P < 0.01) compared with those of cCC. miR-200 family was down-regulated in CC-CC, while miR-200 family was paradoxically up-regulated in cCC (P < 0.01). CC-CC exhibited overt overexpression of mesenchymal markers including ZEB1, Twist, Snail, and vimentin as well an aberrant E-cadherin expression in comparison with cCC. In vitro migration assay showed that cCC cells bearing lower miR-200 s levels exhibited stronger migration ability. Invasive ability of cCC cells was increased after miR-200 s knockdown, accompanied by up-regulation of mesenchymal markers.

CONCLUSIONS: CC-CC was characterized by distinct demographics, precipitating factors, and down-regulation of miR-200 family, compared with those of cCC. The pathogenesis of CC-CC might partly link to the silencing of miR-200 family, acting via ZEB1-directed EMT activation.