Down-regulation of miR-140 induces EMT and promotes invasion by targeting Slug in esophageal cancer

Abstract

Background/Aims: MicroRNAs (miRNAs) are reported to regulate cell invasion and functions by interfering with the translation of target mRNAs, but the role of miRNAs in esophageal cancer (EC) remains unclear. Methods: RT-PCR and Western blot were used to detect the expression of miRNAs and candidate genes in EC samples (n=89). miR-140 mimics and inhibitor were tansfected in human TE-1 and Eca-109 cells. The transwell assay was used to examine the cell invasive ability. The regulation mechanism was confirmed by luciferase reporter assay. The markers of EMT were detected by using Western blot. Results: miR-140 expression was decreased in the EC tissues compared with the corresponding adjacent tumor tissues. Low expression of miR-140 promotes cell invasion by using transwell assay, while the effect of miR-140 high expression is reverse. Slug, a target gene of miR-140, was examined by luciferase assay and Western blot. Conclusions: miR-140 may regulate the cell invasion of EC via controlling Slug expression.