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 mu mol/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. (C) 2007 The WJG Press. All rights reserved.