Published online Oct 15, 1998. doi: 10.3748/wjg.v4.i5.434
Revised: June 22, 1998
Accepted: July 14, 1998
Published online: October 15, 1998
AIM: To study the specific inhibition of HBV gene expression by liver-targeting antisense oligonucleotide (ASON) directed against pre-c and cregious in a sequence specific manner.
METHODS: According to the result of direct sequencing of PCR amplified products, a 16-mer phosphorothioate analogue of the antisense oligonucleotide (PS-ASOn) directed against the HBV U-5-like region was synthesized and then linked with one live-targeting ligand, the galactosylated poly-L-lysine.Their effect on the expression of HBV gene was observed using the 2.2.15 cells.
RESULTS: HBV DNA in the 2.2.15 cells was from HBV with surface antigen subtype ayw 1 by sequencing so that antisense oligonucleotides could bind specifically to the target sequence through base piring. Under the same experimental conditions, the inhibitory rates of PS-ASON to HBsAg and HBeAg were 70% and 58% at a concentration of 10 μmol/L, while by ligand-PS-ASON they were 96% and 82%, the amount of HBV DNA in cultured supernatant and cells was reduced significantly. An unrelated sequence oligonucleotide showed no effectiveness. All the oligonucleotides had no cytotoxicity.
CONCLUSION: Antisense oligonucleotides complexed by the liver-targeting ligand can be targeted to cells via asialoglycoprotein receptors, resulting in supecific inhibition of HBV gene expression and replication.