Published online Mar 15, 2003. doi: 10.3748/wjg.v9.i3.463
Revised: August 23, 2002
Accepted: September 4, 2002
Published online: March 15, 2003
AIM: To construct a novel HBV antisense RNA delivery system targeting hapatocellular carcinoma and study its inhibitory effect in vitro and in vivo.
METHODS: GE7,a 16-peptide specific to EGFR, and HA20, a homologue of N-terminus of haemagglutinin of influenza viral envelope protein, were synthesized and conjugated with polylysin. The above conjugates were organized into the pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system, named AFP-enhancing 4-element complex. Hepatocelluar carcinoma HepG2.2.15 cells was used to assay the in vitro inhibition of the complex on HBV. Expression of HBV antigen was assayed by ELISA. BALB/c nude mice bearing HepG2.2.15 cells were injected with AFP-enhancing 4-element complex. The expression of HBV antisense RNA was examined by RT-PCR and the size of tumor in nude mice were measured.
RESULTS: The AFP-enhancing 4-element complex was constructed and DNA was completely trapped at the slot with no DNA migration when the ratio of polypeptide to plasmid was 1:1.The expression of HBsAg and HBeAg of HepG2.2.15 cells was greatly decreased after being transfected by AFP-enhancing 4-element complex. The inhibitory rates were 33.4% and 58.5% respectively. RT-PCR showed HBV antisense RNA expressed specifically in liver tumor cells of tumor-bearing nude mice. After 4 injections of AFP-enhancing 4-element complex containing 0.2 μg DNA, the diameter of the tumor was 0.995 cm ± 0.35, which was significantly smaller than that of the control groups (2.215 cm ± 0.25, P < 0.05).
CONCLUSION: AFP-enhancing 4-element complex could deliver HBV antisense RNA targeting on hepatocarcinoma and inhibit both HBV and liver tumor cells in vitro and in vivo.