Activity of core-modified 10-23 DNAzymes against HCV

L. ROBALDO; A. BERZAL-HERRANZ; J. MONTSERRAT; A. IRIBARREN

CHEMMEDCHEM

WILEY-V C H VERLAG GMBH

Año: 2014 vol. 9 p. 2172 - 2177

1860-7179

The highly conserved untranslated regions of the hepatitis Cvirus (HCV) play a fundamental role in viral translation and rep-lication and are therefore attractive targets for drug develop-ment. A set of modified DNAzymes carrying (2?R)-, (2?S)-2?-deoxy-2?-C-methyl- and -2?-O-methylnucleosides at various po-sitions of the catalytic core were assayed against the 5?-internalribosome entry site element (5?-IRES) region of HCV. Intracellu-lar stability studies showed that the highest stabilization ef-fects were obtained when the DNAzymes? cores were jointlymodified with 2?-C-methyl- and 2?-O-methylnucleosides, yield-ing an increase by up to fivefold in the total DNAzyme accu-mulation within the cell milieu within 48 h of transfection. Dif-ferent regions of the HCV IRES were explored with unmodified10?23 DNAzymes for accessibility. A subset of these positionswas tested for DNAzyme activity using an HCV IRES-firefly luci-ferase translation-dependent RNA (IRES-FLuc) transcript, in therabbit reticulocyte lysate system and in the Huh-7 human hep-atocarcinoma cell line. Inhibition of IRES-dependent translationby up to 65% was observed for DNAzymes targeting its 285position, and it was also shown that the modified DNAzymesare as active as the unmodified one.