Inhibition of hepatitis B virus expression and replication by RNA interference in HepG2.2.15

AIM: To observe the inhibition of hepatitis B virus replication and expression by transfecting vector-based small interference RNA (siRNA) pGenesil-HBV X targeting HBV X gene region into HepG2.2.15 cells. METHODS: pGenesil-HBV X was constructed and trans- fected into HepG2.2.15 cells via lipofection. HBV antigen secretion was determined 24, 48, and 72 h after trans- fection by time-resolved immunofluorometric assays (TRFIA). HBV replication was examined by fluorescence quantitative PCR, and the expression of cytoplasmic viral proteins was determined by immunohistochemistry. RESULTS: The secretion of HBsAg and HBeAg into the supernatant was found to be inhibited by 28.5% and 32.2% (P < 0.01), and by 38.67% (P < 0.05) and 42.86% (P < 0.01) at 48 h and 72 h after pGenesil-HBV X transfection, respectively. Immunohistochemical stain- ing for cytoplasmic HBsAg showed a similar decline in HepG2.2.15 cells 48 h after transfection. The number of HBV genomes within culture supernatants was also sig- nifi cantly decreased 48 h and 72 h post-transfection as quantifi ed by fluorescence PCR (P < 0.05). CONCLUSION: In HepG2.2.15 cells, HBV replication and expression is inhibited by vector-based siRNA pGenesil- HBV X targeting the HBV X coding region.