AIM:To examine the expressions of N-cadherin and E-cadherin in specimens of 62 normal esophageal epithela,31 adjacent atypical hyperplastic epithelia and 62 esophageal squamous cell carcinomas(ESCCs), and to investigate the roles of N-cadherin in the invasiveness of ESCC 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 specimens of 62 normal esophageal epithelia,31 adjacent atypical hyperplastic epithelia and 62 ESCCs.The invasiveness of ESCC line EC9706 was determined by transwell assay after EC9706 was transfected by N-cadherin shRNA. RESULTS:The positive rates of N-cadherin decreased in the carcinoma,adjacent atypical hyperplastic and normal esophageal tissues(75.8%,61.3%and 29.0%, P<0.05),respectively,while those of E-cadherin increased(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 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.The number of cells which crossed the basement membrane filter decreased from 123.40±8.23 to 49.60±6.80(P< 0.05).CONCLUSION:E-cadherin and N-cadherin expression is correlated with the invasion and aggravation of ESCC.The down-regulation of N-cadherin lowers the invasiveness of EC9706 cell line. AIM: To examine the expressions of N-cadherin and E-cadherin in specimens of 62 normal esophageal epithela, 31 adjacent atypical hyperplastic epithelia and 62 esophageal squamous cell carcinomas (ESCCs), and to investigate the roles of N-cadherin in the invasiveness of METHODS: PV immunohistochemistry was used to detect the expression pattern of N-cadherin and E-cadherin in specimens of 62 normal esophageal epithelia, 31 adjacent atypical hyperplastic epithelia and 62 ESCCs.The invasiveness of RESULTS: The positive rates of N-cadherin decreased in the carcinoma, adjacent atypical hyperplastic and normal esophageal tissues (75.8%, 61.3% and 29.0%, P <0.05). Respectively, while those of E-cadherin increased (40.3%, 71.0% and 95.2%, P <0.05). iation, 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. The number of cells which crossed the basement membrane filter decreased from 123.40 ± 8.23 ​​to 49.60 ± 6.80 (P <0.05) .CONCLUSION: E-cadherin and N-cadherin expression is correlated with the invasion and aggravation of ESCC.The down-regulation of N-cadherin lowers the invasiveness of EC9706 cell line .