RNA Interference Mediated Inhibition of Gene Expression Using Chemically Modified Short Interfering Nucleic Acid (siNA)
The present invention concerns methods and reagents useful in modulating gene expression in a variety of applications, including use in therapeutic, cosmetic, cosmeceutical, prophylactic, diagnostic, target validation, and genomic discovery applications. Specifically, the invention relates to synthetic chemically modified small nucleic acid molecules, such as short interfering nucleic acid (siNA), short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA) molecules capable of mediating RNA interference (RNAi) against target nucleic acid sequences. The small nucleic acid molecules are useful in the treatment of disease (e.g., cancer, proliferative, inflammatory, metabolic, autoimmune, neurologic, ocular diseases), condition, trait (e.g., hair growth and removal), genotype and phenotype that responds to modulation of gene expression or activity in a cell, tissue, or organism. Such small nucleic acid molecules can be administered systemically, locally, or topically.
1 - 20 . (canceled)
21 . A chemically modified short interfering nucleic acid (siNA) molecule that inhibits expression of a target RNA, wherein:
a) the siNA comprises a sense strand and an antisense strand;
b) each strand is independently 18 to 24 nucleotides in length, and together comprise a duplex having between 17 and 23 base pairs;
c) the antisense strand is complementary to the target RNA sequence;
d) the sense strand has a cap at both 5′- and 3′-ends of the sense strand; and
e) pyrimidine nucleotides in the sense strand are pyrimidine ribonucleotides and purine nucleotides in the sense strand are 2′-O-methyl purine nucleotides.
22 . The siNA molecule of claim 21 , comprising a 3′-overhang on one or both strands.
23 . The siNA molecule of claim 21 , wherein pyrimidine nucleotides in the antisense strand are 2′-deoxy-2′-fluoro pyrimidine nucleotides and purine nucleotides present in the antisense strand are 2′-O-methyl purine nucleotides.
24 . The siNA molecule of claim 23 , wherein the antisense strand has a phosphorothioate internucleotide linkage at the 3′end.
25 . The siNA molecule of claim 23 , comprising three ribonucleotides at the 5′-terminus of the antisense strand.
26 . A composition comprising the siNA molecule of claim 21 and a pharmaceutically acceptable carrier or diluent.