Effect of N-cadherin knock-down on invasiveness of esophageal squamous cell carcinoma

e15571 Background: Cell adhesion molecules are of crucial importance in cancer invasion and metastasis. Epithelial to mesenchymal transition, characterized by reduced E-cadherin and increased N-cadherin expression, has been recognized as a feature of aggressive tumors, but the importance of this phenotype has not been settled in esophageal squamous cell carcinoma. Aim: To examine the expressions of N-cadherin and E-cadherin in 62 normal esophageal epithelium specimens, 31 adjacent atypical hyperplasia epithelium specimens and 62 esophageal squamous cell carcinoma specimens, and to investigate the roles of N-cadherin in the invasiveness of esophageal squamous cell carcinoma cell line EC9706 transfected by N-cadherin shRNA.. Methods: PV immunohistochemistry was used to detect the expression pattern of N-cadherin and E-cadherin in 62 normal esophageal epithelium specimens, 31 adjacent atypical hyperplasia epithelium specimens and 62 esophageal squamous cell carcinoma specimens. The invasiveness of esophageal squamous cell carcinoma cell line EC9706 in vitro and in vivo was determined by transwell assay and nude mice experiments after EC9706 was transfected by N-cadherin shRNA. Results: The positive rates of N-cadherin decreased in the sequence of carcinoma, adjacent atypical hyperplasia and normal esophageal tissue, which were 75.8%, 61.3%, 29.0% (P < 0.05), respectively, while those of E-cadherin increased in sequence, which were 40.3%, 71.0% and 95.2% (P < 0.05). The increased expression of N-cadherin and decreased expression of E-cadherin were related to the invasion, differentiation, and lymph node metastasis (P < 0.05). The expression level of N-cadherin decreased in the N- cadherin knocked down cells, and the invasiveness of those cells decreased significantly as well in vitro and in vivo. Conclusions: These results suggest that N-cadherin is an important factor in the invasiveness of esophageal squamous cell carcinoma and N-cadherin may serves as a potential molecular target for biotherapy of esophageal squamous cell carcinoma. No significant financial relationships to disclose.