Abstract: Objective To construct the small interfering RNA (siRNA) targeting heparanase gene and its expressing vector,and to observe its interference effect on the expression of heparanase gene and inhibitory effect on the invasive potential of human malignant melanoma A375 cells.Methods Three siRNAs were designed.The recombinant plasmid pRNATU6.1/heparanase-siRNA was designed and constructed. A375 cells were cultured,and transfected with pRNATU6.1/heparanase-siRNA.The cells treated with lipofectamine or Opti-MEM served as the controls.Real-time fluorescence quantitative PCR and Western blot were performed to evaluate the expression of heparanase RNA and protein in these treated A375 cells.The in vitro invasive potential of treated A375 cells was assessed by Matrigel gel assay.Results The siRNA targeting heparanase gene was successfully cloned to the eukaryotic expressing vector pRNATU6.1.The expression levels of both heparanase RNA and protein decreased significantly in siRNA-transfected A375 cells than those in the control cells.The in vitro invasive potential of siRNA-transfected cells was also significantly inhibited as compared with that of the control cells (P<0.01).Conclusions The siRNA targeting heparanase gene and its expressing vector are successfully constructed,and the designed siRNAs could significantly decrease the mRNA and protein expression of heparanase in A375 cells.

Key words: RNA interference, Gene express, Melanoma, Heparanase