Inhibition of HBV-DNA replication and expression by siRNA based on magnetic nanoparticles transfering in HepG2 2.2.15 cells.

Objective: To investigate the inhibitory effect of downregulation of hepatitis B virus (HBV) core gene (HBcAg) expression by RNA interference and magnetic nanoparticles on both HBV DNA replication and expression in vitro.

Methods: HepG2 2.2.15 cells were transfected with U6 promoter plasmids coding for small interfering RNA (siRNA) targeting HBV core gene using magnetic nanoparticles. RT-PCR and Western blot were used to assess the mRNA and protein expression HBV core antigen. Real-time PCR was used to evaluate the suppression efficiency of HBV-DNA replication and expression; and radioimmunoassay was used for HBV surface antigen (HBsAg), core antigen (HBcAg), and e antigen (HBeAg) detection.

Results: We successfully constructed nanoparticles with siRNA plasmid targeting HBV core antigen; HBcAg mRNA and HBV core antigen protein levels were significantly reduced in the transfected cells. HBV-DNA downregulation was estimated at 4-5 logs and the HBsAg and HBeAg levels were also reduced compared with the controls.

Conclusions: Downregulation of HBV core gene using RNAi technology and magnetic nanoparticles can potentially be used as a therapeutic strategy for Hepatitis B.