OBJECTIVETo evaluate interfering effect of several short interfering RNAs (siRNA) on HCV 5' untranslated region(5' UTR).

METHODSThe green fluorescent protein (GFP) was used as reporter gene. A fused gene of HCV-5'UTR and GFP was constructed. It was cloned into the plasmid pCDNA3.1 named as pcDNA-HCV-5'UTR-GFP. Three siRNAs were designed and transfected into HepG2 cells with pcDNA-HCV-5'UTR-GFP. The change of the fluorescence intensity of HepG2 cells was shown by fluorescence microscopy and numerically detected under 488 nm wave length by flow cytometry.

RESULTSThe fused gene of HCV-5'UTR and GFP was successfully constructed. The seven groups displayed inhibitory effects on the gene expression of GFP. The inhibition rates of siRNA A, B and C were 68.4 percent, 72.6 percent and 75.6 percent, respectively. The inhibitory rates of siRN A + B, siRN B +C and siRN A +C were 91.8 percent, 87.2 percent and 92.4 percent, respectively. The inhibitory rates of siRN A+B +C was the highest, up to 95.7 percent.

CONCLUSIONThese siRNAs could inhibit expression of HCV 5'UTR gene, the inhibitory effect of combined siRNA was better than that of single siRNAs.