Aquaporin 1 is a prognostic marker and inhibits tumour progression through downregulation of Snail expression in intrahepatic cholangiocarcinoma.

ABSTRACT

BACKGROUND: Recently, some studies have suggested a link between AQP1 and cancer progression. AIMS: The aim of the present study was to investigate the influence of AQP1 on the clinicopathology and prognosis of intrahepatic cholangiocarcinoma (ICC) patients. METHODS: We retrospectively detected the expression of AQP1 protein in 307 patients with ICC who underwent partial hepatectomy. Western blot analysis was used to detect AQP1 protein levels in stable AQP1 overexpression and knockdown cell lines. The influence of AQP1 on the invasion and metastasis ability of ICC cells was assessed by wound-healing and Transwell assays in vitro as well as by a splenic liver metastasis model in vivo. RESULTS: Positive membranous AQP1 expression was identified in 34.2% (105/307) of the ICC specimens. Survival data revealed that positive AQP1 expression was significantly associated with favourable disease-free survival (DFS) and overall survival (OS) (p = 0.0290 and p = 0003, respectively). Moreover, high AQP1 expression inhibited the invasion and migration of ICC cells in vitro as well as inhibited liver metastasis in nude mice. Mechanistically, high AQP1 expression in ICC cells increased the levels of E-cadherin but decreased the levels of the Snail transcription factor. CONCLUSIONS: AQP1 expression is associated with a favourable prognosis in ICC patients. AQP1 inhibits ICC cell invasion, metastasis, and epithelial-mesenchymal transition (EMT) through downregulation of Snail expression.