Combination of small interfering RNA and lamivudine on inhibition of human B virus replication in HepG2.2.15 cells

AIM: To observe the inhibition of hepatitis B virus (HBV) replication and expression by combination of siRNA and lamivudine in HepG2.2.15 cells. METHODS: Recombinant plasmid psil-HBV was constructed and transfected into HepG2.2.15 cells. The transfected cells were cultured in lamivudine-containing medium (0.05 micromol/L) and harvested at 48, 72 and 96 h. The concentration of HBeAg and HBsAg was determined using ELISA. HBV DNA replication was examined by real-time PCR and the level of HBV mRNA was measured by RT-PCR. RESULTS: In HepG2.2.15 cells treated with combination of siRNA and lamivudine, the secretion of HBeAg and HBsAg into the supernatant was found to be inhibited by 91.80% and 82.40% (2.89+/-0.48 vs 11.73+/-0.38, P<0.05; 4.59+/-0.57 vs 16.25+/-0.48, P<0.05) at 96 h, respectively; the number of HBV DNA copies within culture medium was also significantly decreased at 96 h (1.04+/-0.26 vs 8.35+/-0.33, P<0.05). Moreover, mRNA concentration in HepG2.2.15 cells treated with combination of siRNA and lamivudine was obviously lower compared to those treated either with siRNA or lamivudine (19.44+/-0.17 vs 33.27+/-0.21 or 79.9+/-0.13, P<0.05). CONCLUSION: Combination of siRNA and lamivudine is more effective in inhibiting HBV replication as compared to the single use of siRNA or lamivudine in HepG2.2.15 cells.