Abstract: Recent studies show that tumor cells get rid of the connections between cells, and induce tumor invasion and metastasis through epithelialmesenchymal transition (EMT). EMT becomes an important way to invasion, metastasis and chemotherapy resistance of epithelial cell carcinoma which accounting for more than 90% of malignant carcinomas. Members of Snail family, especially Snail  is regarded as important adjustment factor of EMT, which induce the transformation from epithelial cell to mesenchymal phenotype through competitive inhibition Ecalcium protein gene expression. Many researches show that EMT exists widely in  digestive system tumors, which is closly related to the invasion, metastasis and chemotherapy resistance of digestive system tumors.

Key words: Epithelial-mesenchymal transition, Digestive system neoplasms, Glycoproteins