[Effect of transcriptional factor snail on epithelial-mesenchymal transition and tumor metastasis].

BACKGROUND & OBJECTIVE: Transcription factor Snail mediates epithelial-mesenchymal transition (EMT), and is associated with tumor metastasis. This study was designed to observe the enhancive effect of Snail and the reverse effect of antisense-Snail on EMT of tumor cells, and explore the role of Snail in tumor metastasis. METHODS: Snail cDNA was transfected into canine renal epithelial cell line MDCK; antisense-Snail was transfected into human breast cancer cell line MDA-MB231. The expression of epithelial markers E-cadherin, beta-catenin and Cytokeratin 18, mesenchymal marker Fibronectin, metastasis-related marker matrix metalloproteinase-2 (MMP-2), and RhoA were detected by Western blot. The metastatic potential of tumor cells was examined by in vitro cell wound model and Boyden chamber invasion assay. RESULTS: The invasion potential of MDCK cells was enhanced after transfection of Snail. The expression of E-cadherin, beta-catenin, and Cytokeratin 18 was significantly lower in Snail-transfected MDCK cells than in control cells (P < 0.05); the expression of Fibronectin, MMP-2, and RhoA was significantly higher in Snail-transfected cells than in control cells (P < 0.05). Inhibiting the expression of Snail with antisense-Snail in MDA-MB231 cells led to opposite results. CONCLUSION: Snail promotes EMT in normal epithelial cells, and inhibiting the expression of Snail may reverse EMT and suppress tumor metastasis.