Objective    To investigate the inhibitory effect of RNA interference (RNAi) on WT1 gene expression in HL-60 cell line.     Methods    Several pairs of small interfering RNA (siRNA) for WT1 gene was designed and transfected into HL-60 cells. WT1 gene expression was assessed by RT-PCR

and WT1 protein expression was tested by Western blot. Flow cytometry was used to measure the cell apoptosis.     Results    The expression rates of WT1 mRNA and the expression rates of WT1 protein were (23.62%±1.28%)

(23.20%±1.04%)

  respectively in HL-60 WT1 siRNA-transfected cells

  significantly lower than those of control cells (P0.05); The apoptosis rates were (13.72%±1.33%)

significantly higher than those of control cells (P0.05).     Conclusion    Expression of WT1 gene can be effectively inhibited by siRNA in HL-60 cells. The siRNA targeting human WT1 is considered to be possible tool against leukemia.