AIM: To determine the inhibitory effect of the adenovirus- based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad/Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal cancer cell line Eca109. METHODS: siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad/Ang-1si (Eca109/Ang-1si), and Ad/si was used to infect Eca109 cells as control (Eca109/si). Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell (HUVEC) migration and proliferation were analyzed. After s.c. injection into athymic nu/nu mice, the tumor growth, vessel density and apoptosis of each group was also determined. RESULTS: HUVEC migration induced by conditioned medium from Ang-1si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovirus- transfected Eca109 cells. Furthermore, after s.c. injection into athymic nu/nu mice, the tumor growth and cell apoptosis of Ad/Ang-1si -expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. Vessel density assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased. CONCLUSION: The targeting Ang-1 may provide a therapeutic option for esophageal cancer. AIM: To determine the inhibitory effect of the adenovirus-based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad / Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal Cancer cell line Eca109. METHODS: siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad / Ang-1si (Eca109 / Ang- 1si), and Ad / si was used to infect Eca109 cells as control (Eca109 / si). Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell (HUVEC) migration and proliferation were analyzed. After sc injection into athymic nu / The HUVEC migration induced by conditioned medium from Ang-1 si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovir us-transfected Eca109 cells. Furthermore, after sc injection into athymic nu / nu mice, the tumor growth and cell apoptosis of Ad / Ang-1si-expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased. CONCLUSION: The targeting Ang-1 may provide a therapeutic option for esophageal cancer.