miR-25 promotes metastasis via targeting FBXW7 in esophageal squamous cell carcinoma.

Increasing evidence suggests that miR-25 can function as an oncogene in different types of human malignancies, whereas little is known concerning the role of miR-25 in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to investigate the role of miR-25 in ESCC and to determine the molecular mechanisms underlying its function. The expression level of miR-25 was detected in primary ESCC tissues and cell lines by real-time quantitative PCR. We also assessed whether knockdown of miR-25 influences in vitro cell invasion and migration. Western blot analysis was used to detect the influence of miR-25 on a target gene, and Pearson analysis was used to calculate the correlation between the expression of a target gene and miR-25 in ESCC tissues. The results revealed that the relative level of miR-25 expression was significantly upregulated in ESCC tissues and cell lines. Expression of miR-25 in ESCC tissues was positively associated with depth of tumor invasion and tumor stage. Moreover, high miR-25 expression conferred poorer overall survival (OS), and a multivariate analysis revealed that miR-25 was an independent risk factor for OS. In addition, knockdown of miR-25 in ESCC cells significantly suppressed cell migration and invasion. Furthermore, we identified F-box and WD repeat domain-containing 7 (FBXW7) protein as a direct functional target of miR-25 in ESCC. In conclusion, the present study supports the potential of miR-25 as a prognostic predictor with its high expression in cancer tissues and its association with tumor progression by targeting FBXW7 in ESCC.