Inhibition of IL-6 in mice by anti-NF-kappaB oligodeoxyribonucleotide N3'-->oligodeoxyribonnucleotide N3' --> P5' phosphoramidates.

Oligonucleotide N3'->P5' Phosphoramidates (PN) may confer advantages over unmodified phosphodiester compounds for therapeutic applications (1). Previous in vitro data demonstrated that PN Oligodeoxynucleotides (ODNs) possess several advantageous features, including RNase H-independence, an improved resistance to nuclease degradation, decreased protein binding, and high affinity sequence-specific binding to complementary RNAs (1, 2). Consequently, we undertook a study to investigate the effects of PN antisense (AS) oligos targeted against the p65 subunit of the Nuclear Factor Kappa beta (NF-kappaB) transcription factor in vivo, in mice. The ability of the antisense molecules to inhibit IL-6 elevation induced by lipopolysaccharide (LPS) in mice, was studied. A 16 mer uniformly modified PN and a chimeric phosphoramidate-phosphodiester oligodeoxynucleotide complementary to the region surrounding the starting codon, (PN-PO-PN) of the NK-kappaB p65 subunit mRNA, both caused a sequence specific reduction of the serum IL-6 level in mice. A scrambled oligodeoxynucleotide showed much lower IL-6 inhibition in mice. These results show that the p65 PN-AS can modulate expression of IL-6 in mice without uptake enhancers and therefore may be a useful prototype for RNAse-H independent therapeutic agents.