Abstract: Abstract:Objective To investigate the effects of Ku80 on cell adhesion and invasion of human esophageal carcinoma cells by using shRNA vector to evoluate the inhibition of Ku80 expression. Methods The effectiveness and feasibility of RNA interference were confirmed by Western blot and RT-PCR methods. Effects of silencing Ku80 gene on cell adhesion and invasion of esophageal carcinoma cells were investigated by cell adhesion assay and cell invasion assay,respectively. Results The express of Ku80 protein was reduced by shRNA-H2 and K3.The inhition rate was 63% and 50% for shRNA-H and K3,respectively（P<0.01）. Content of Ku80 mRNA was reduced by shRNA-H2 and K3, respectively to 84% and 58%（P<0.01）.Adhesion rate of human esophageal carcinoma cells was inhibited by shRNA-H2 and K3, respectively (63.19±4.93)% and (52.87±2.67)%. Cell invasion was inhibited by shRNA-H2 and K3.Its inhibiton rate was 69.6% and 62.1% (P<0.01),respectively. Conclusion Ku80 plays a role in invasion and migration of esophageal cancer.The inhibition of Ku80 expression was induced by shRNA,which means that silencing Ku80 gene may become a target of gene therapy to tumor.