ENA oligonucleotides as therapeutics.

: Oligonucleotides containing 2'-O,4'-C-ethylene-bridged nucleic acid (ENA) residues have two notable properties: (i) considerable affinity to complementary single-stranded RNA and double-stranded DNA; and (ii) dramatically high resistance against nucleases. On the basis of these properties, the in vitro and in vivo applications of ENA for gene silencing as antisense oligonucleotides, triplex-forming oligonucleotides and small interfering RNAs are discussed here. ENA oligonucleotides also have potential as therapeutic agents for Duchenne muscular dystrophy by a mechanism of exon skipping.