Abstract: Objective：To determine the expression of Snail and Ecadherin in esophageal squamous cell carcinoma （ESCC）.To detect the effect of Snail on influencing the migration and invasion of ESCC by targeting Ecadherin.Methods：The expression of Snail and Ecadherin were detected in 30 clinical ESCC samples and its adjacent normal epithelial samples via Polymerase Chain Reaction （PCR）.The relative expression of Snail and Ecadherin in ESCC and its adjacent normal tissue were analysed with these 30 patients’ clinical pathological characteristics .The expression of Snail and Ecadherin in 4 random pairs of these 30 samples were investigated via Western Blot.Based on cell transfection of one ESCC cell line，the expression of Snail was downregulated with the Snail small interfering RNA （siRNA）.Then the expression of Snail and Ecadherin expression in these models were analyzed and the cell wound healing assay and invasion functional experiment were carried out.Result：The relative expression of 30 cases of esophageal squamous cell carcinoma was higher than that of the adjacent tissues of Snail（1.96±0.75/0.52±0.43，P=0.04），the relative expression of Ecadherin was low（0.66±0.31/2.19±0.62，P=0.02）.Depth of tumor invasion （P=0.009）and tumor metastasis to lymph nodes （P=0.047）were associated with overexpression of Snail and lowexpression of Ecadherin .In 4 random matched samples，the expression of Snail was 0.73±0.13 in cancer samples and 0.23±0.08 in its adjacent samples，meanwhile the expression of Ecadherin was 0.10±0.06 in tumor tissues and 0.60±0.14 in normal tissues（P=0.00）.The cell line EC109 was selected into the transfection model.Compared with negative control group，depression of Snail（0.53±0.05/1.00±0.15，P=0.00）could restore the expression of Ecadherin （3.28±0.26/1.00±0.18，P=0.00）in mRNA level，as well as in the level of protein（0.25±0.05/0.41±0.10，P=0.03；0.83±0.11/0.29±0.05，P=0.02）.Downregulated the expression of Snail also decreased the capability of migration and invasion in EC109（P<0.05）.Conclusion：Relatively high expression of Snail in ESCC may influence the migration and invasion in ESCC by regulating Ecadheirn.

Key words: esophageal squamous cell carcinoma, Snail, E-cadherin, migration, invasion