Abstract: Objective To knock down the expression of angiopoietin-1 in human gastric cancer cell line BGC-823, and observe the treatment effect of reversing tumor invasion phenotype. Methods To design the siRNA sequence fragments targeting angiopoietin-1 and transfer it into human gastric cancer cell line BGC-823. RT-PCR method was used to explore the expression of angiopoietin-1 mRNA, western blot and immunofluorescence methods were used to test the expression of three invasion-associated proteins, including integrin β1, CD44V6 and Ang-1. Cell adhesion assay was employed to detect the cellular adhesion ability, matrigel and transwell plastic dual-chamber culture system for detection of cancer cell invasion. Results The siRNA sequence fragments can knock down Ang-1 mRNA level through RT-PCR results. The expression of integrin β1, CD44V6 and Ang-1 were lower significantly than control group（P<0.05）, as so as the cellular adhesion and invasion abilities（P<0.05）. Conclusion The siRNA technique targeting angiopoietin-1 can reverse the invasion phenotype of human gastric cancer cell line BGC-823, and may provide new ideas and reference for future gene therapy for gastric cancer.

Key words: Angiopoietin-1, RNA interference, stomach neoplasms, neoplasm invasiveness, antigens, CD29, antigens, CD44