RESUMO
<p><b>OBJECTIVE</b>To construct the plasmid expression vector pSIH1-H1-copGFP for RNA interference against vascular endothelial growth factor C (VEGF-C) and to evaluate its effect on the expression of VEGF-C mRNA in gastric cancer cells after transfection.</p><p><b>METHODS</b>Three siRNAs of genome sequence of VEGF-C gene were retrieved from GenBank and one negative chain was used as control. Four siRNAs were cloned into plasmid pSIH1-H1-copGFP,which were then transfected into gastric cancer cells (SGC7901). The expression of VEGF-C mRNA was analyzed by RT-PCR.</p><p><b>RESULTS</b>The recombinant plasmid of pSIH1-H1-copGFP specific for VEGF-C was confirmed by gene sequencing analysis. The target sequence obtained was completely consistent with the design. Transfection efficiency of the three siRNAs ranged from 60% to 70%. After transfection, the expression of VEGF-C mRNA in SGC7901 cells was significantly inhibited. Inhibition rates of VEGF-C mRNA expression were 35.4%, 33.8% and 81.5% in the three siRNA plasmid vectors, respectively.</p><p><b>CONCLUSION</b>The siRNA expression plasmid vector against VEGF-C mRNA is successfully constructed, and RNAi may be a useful technique to inhibit the lymphangiogenesis of gastric cancer.</p>