Overexpression of ZEB1 associated with metastasis and invasion in patients with gastric carcinoma.

The aim of this study was to investigate the expression of ZEB1 in gastric carcinoma, its correlation with the clinicopathology of gastric carcinoma, and the role of ZEB1 in invasion and metastasis in gastric carcinoma. ZEB1 expression was analyzed by immunohistochemistry and Western blot in 45 gastric carcinoma tissue samples that contained the adjacent gastric mucosa. The correlation between ZEB1 expression, the occurrence and development of gastric cancer, and clinical pathology was investigated. ZEB1 expression in the human gastric carcinoma cell line AGS was downregulated by RNA interference, and changes in ZEB1 expression corresponded with changes in the invasive and metastatic ability of AGS cells. Immunohistochemistry revealed that ZEB1 protein expression in gastric carcinoma tissues was significantly higher than in normal gastric mucosa tissues (p < 0.001). A lower degree of differentiation of gastric cancer (p = 0.009), a higher TNM (tumor, node, and metastasis) stage (p = 0.010), and a larger scope of invasion were correlated with higher expression of ZEB1 (p = 0.041, 0.002). However, the expression of ZEB1 in gastric carcinoma tissue was independent of gender, age, and tumor size (p > 0.05). Western blot results also showed that ZEB1 protein expression was significantly higher in gastric carcinoma tissue than in the adjacent normal gastric mucosa tissue (p = 0.008). A lower degree of differentiation of the gastric carcinoma correlated with a higher TNM stage, and a larger scope of invasion correlated with increased ZEB1 expression (p = 0.023). Transfection of ZEB1 siRNA in AGS cells significantly decreased the expression level of ZEB1 protein (p = 0.035). Furthermore, the number of cells that could pass through the Transwell chamber was significantly lower in the transfected group than in the non-transfected control group (p = 0.039), indicating that the suppression of ZEB1 expression could significantly reduce the invasive and metastatic ability of AGS cells (p = 0.005). Concluding, in gastric carcinoma tissue, overexpression of ZEB1 may be related to the occurrence and development as well as invasion and metastasis of gastric carcinoma.