Zq. Yao et al., SPECIFIC-INHIBITION OF HEPATITIS-B VIRUS GENE-EXPRESSION BY AN ANTISENSE OLIGONUCLEOTIDE IN-VITRO, Acta virologica, 39(4), 1995, pp. 227-230
It was previously shown that a number of antisense oligonucleotides ag
ainst hepatitis B virus (HBV) mRNAs were highly effective in inhibitio
n of HBV gene expression (Yao et al., 1995). Here, using radioisotope
techniques, we report a specific inhibition of HBV surface antigen (HB
sAg) production in vitro by 2.2.15 cells (Hep-G2 cells transfected wit
h HBV genome) by the antisense oligonucleotide 15-S-asON, a 15-mer pho
sphorothioate analogue complementary to the cap site of the SPII promo
ter of HBV mRNA, at a concentration of 2-5 mu mol/l. After 24 and 48 h
rs of incubation of cells with 15-S-asON, the intracellular concentrat
ion of the latter rose to 69.4 and 75.8 nmol/l, respectively, and the
HBsAg level assayed by ELISA was reduced by 50.0% and 70.6%, respectiv
ely. These results were checked by use of the radioimmunoprecipitation
method: 2.2.15 cells exposed to 15-S-asON and labelled with [S-35]-me
thionine for 48 hrs showed a decrease of the HBsAg level by 81.26% but
almost none of the total proteins. No cytotoxicity of the 15-S-asON w
as observed with regard to the cell morphology and growth. These resul
ts indicate that the tested antisense oligonucleotide specifically inh
ibits the HBV gene expression.