Inhibition of expression of hepatitis C virus 1b genotype core and NS4B genes in HepG2 cells using artificial microRNAs

The present study aimed to evaluate the silencing effect of artificial microRNAs (amiRNAs) against the hepatitis C virus (HCV) 1b (HCV1b) genotype core (C) and non-structural protein 4B (NS4B) genes. pDsRed-monomer-Core and pDsRed-monomer-NS4B plas- mids, containing the target genes were constructed. A total of eight artificial micro RNA (amiRNA)‑expressing plasmids, namely, pmiRE-C-mi1 to -mi4 and pmiRE-NS4B-mi1 to -mi4, were designed and constructed to interfere with various sites of the core and NS4B genes, and the amiRNA inter- fering plasmid and the corresponding target gene‑expressing plasmid were co-transfected into HepG2 cells. At 48 h after transfection, HCV core and NS4B gene expression levels were detected using fluorescence microscopy, flow cytometry, reverse transcription quantitative polymerase chain reaction and western blot analysis. Fluorescence microscopy revealed that the target gene‑transfected cells expressed red fluores - cent protein, whereas the interfering plasmid-transfected cells exhibited expression of green fluorescent protein. The percentage of red fluorescent proteins and mean fluorescence intensity, as well as protein expression levels of the core and NS4B genes within the cells, which were co-transfected by the amiRNA interfering plasmid and the target gene, were signifi - cantly decreased. The results of the present study confirmed that amiRNAs may effectively and specifically inhibit the expression of HCV1b core and NS4B genes in HepG2 cells, potentially providing a novel therapeutic strategy for the treat- ment of HCV.