Objective:To detect the expression of 5-LOX and observe its inhibitory effect in humane pancreatic cancer cell.Methods:5-LOX mRNA and protein expression were analyzed by RT-PCR and immunocytochemical staining as well as images analyzing system,and the effect of MK886 was tested.Results:MK886 effectively down-regulated the expression of 5-LOX mRNA.Immunocytochemical staining and images analysis confirmed that the expression 5-LOX protein in cell treated with MK886 was lower than untreated control cell.Conclusion:Inhibitor of 5-LOX can effectively prevent the target mRNA into protein product,thus block or weaken the expression of 5-LOX.