The effect of epithelial–mesenchymal transition induced by snail transfection in esophageal squamous cancer cell lines.

Abstract

e14505 Background: Cancer stem cell (CSC) has been shown to be an important player in tumorigenesis and tumor progression. Epithelial-mesenchymal transition (EMT) is closely linked with processes in embryogenesis and it has been shown that EMT generates properties of stem cell-like cells in human cancer. Methods: A lentivirus system was used to overexpress human Snail, an EMT regulator, by transfection with a plasmid (pLV-EF1a-hSnail-Hyg), into KYSE 170 and KYSE 510 esophageal squamous cell carcinoma (ESCC) cell lines (kindly provided by Dr. Yutaka Shimada). Immunoblotting was used to determine expression of EMT associated markers (i.e., vimentin, E-cadherin, fibronectin and N-cadherin). Migration and invasion assays were conducted in Snail-transfected cells with a comparison to their vector controls. Cytotoxicity (MTT) and cell proliferation assay were used to determine cell growth properties. In addition, sphere formation assay and flow cytometry (FCM) were employed to characterize in part stem cell properties while examining expression of stemness gene by real-time polymerase chain reaction (PCR). Results: After Snail transfection, mesenchymal markers, vimentin and N-cadherin increased, whereas epithelial marker E-cadherin decreased.Snail-transfected ESCC cells presented a significant increase in RNA expression of stemness genes (i.e., Nanog, Oct4, ABCG2 and Sox2) and in sphere formation. Invasion ability increased after Snail-transfection in ESCC cell lines with a decreased chemosensitivity to cisplatin, taxol, 5’ FU and suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor. Conclusions: Our results demonstrated that Snail induced EMT generated properties of CSC in ESCC cell lines.