Objective Pancreatic cancer is one of the most deadly cancers,which is characterized by its high metastatic potential.S100A4 is a major prometastatic protein involved in tumor invasion and metastasis which precise role in pancreatic cancer has not been fully investigated.We knocked down the S100A4gene in the Bxpc-3 pancreatic cancer cell line via RNA interference to study the changes in cell behavior.Methods Real-time polymerase chain reaction and western blotting were used to detect mRNA and protein expression levels of S100A4,matrix metalloproteinase (MMP)-2,E-cadherin and thrombospondin (TSP)-1.Transwell chambers were used to detect the migration and invasion abilities; a cell adhesion assay was used to detect adhesion ability; colony forming efficiency was used to detect cell proliferation; flow cytometry was used to detect apoptosis.Results S100A4 mRNA expression was reduced to 17％ after transfection with S100A4-siRNA,and protein expression had a similar trend.mRNA and protein expression of MMP-2 was reduced and that of E-cadherin and TSP-1 was elevated,indicating that S100A4 affects their expression.S100A4-silenced cells exhibited a marked decrease in migration and invasiveness and increased adhesion,whereas overall proliferation and apoptosis were not overtly altered.Conclusion S100A4 and its downstream factors play important roles in pancreatic cancer invasion,and silencing A100A4 can significantly contain the invasiveness of pancreatic cancer.