The present invention concerns methods and reagents useful in modulating gene expression in a variety of applications, including use in therapeutic, 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 any disease or condition that responds to modulation of gene expression or activity in a cell, tissue, or organism.

One aspect of the present invention relates to double-stranded RNA (dsRNA) agent capable of inhibiting the expression of a target gene. The sense strand of the dsRNA agent comprises at least one thermally destabilizing nucleotide, and at least one said thermally destabilizing nucleotide occurring at a site opposite to the seed region (positions 2-8) of the antisense strand; and the antisense strand of the dsRNA agent comprises at least two modified nucleotides that provide the nucleotide a steric bulk that is less than or equal to the steric bulk of a 2′-OMe modification, wherein said modified nucleotides are separated by 11 nucleotides in length. Other aspects of the invention relates to pharmaceutical compositions comprising these dsRNA agents suitable for therapeutic use, and methods of inhibiting the expression of a target gene by administering these dsRNA agents, e.g., for the treatment of various disease conditions.

This disclosure relates to particles conjugated to therapeutic nucleic acids. In certain embodiments, the nucleic acid comprises a sequence that catalytically cleaves RNA, e.g., DNAzyme or RNAzyme. In certain embodiments, the particles contain nucleic acids with both DNAzyme and/or RNAzyme and siRNA sequences. The cleaving nucleic acids optionally comprise a sequence functioning to hybridize to a target of interest and/or the particles are further conjugated to a targeting moiety. In certain embodiments, conjugated particles are used in the treatment or prevention of cancer or viral infections or bacterial infections. In certain embodiments, conjugated particles are used in detecting metal ions and other small molecule analytes.

The invention provides for double stranded nucleic acid molecules comprising a 5′ extension of the sense or antisense strand and further comprising a plurality of nucleotides that are conjugated to a ligand and methods of using the double-stranded nucleic acid molecules. Ligand-modified oligomers where the sense stands form a tetraloop provide new potent and stable RNA interference agents. These dsNA molecules are synthesized using a plurality of nucleotides that include ligand-modified monomers, nucleotide analog monomers, modified nucleotide monomers and the like, using standard nucleotide synthetic methods and systems.

One aspect of the present invention relates to double-stranded RNAi (dsRNA) duplex agent capable of inhibiting the expression of a target gene. The dsRNA duplex comprises one or more motifs of three identical modifications on three consecutive nucleotides in one or both strand, particularly at or near the cleavage site of the strand. Other aspects of the invention relates to pharmaceutical compositions comprising these dsRNA agents suitable for therapeutic use, and methods of inhibiting the expression of a target gene by administering these dsRNA agents, e.g., for the treatment of various disease conditions.

Disclosed herein are double stranded nucleic acid molecules and pharmaceutical compositions comprising same useful in the treatment of, inter alia, acute and chronic inflammation, neuropathic pain, primary graft dysfunction (PGD) after lung transplantation in a subject in need thereof. The compounds are preferably chemically synthesized and modified dsRNA compounds, which down regulate or inhibit expression of Toll like receptor 4.

The invention provides, among other things, methods of stabilizing mRNA and nuclease resistant mRNA prepared in accordance with such methods. In certain embodiments, the nuclease resistant mRNA encodes a functional protein, such as enzyme, and is characterized by its resistance to nuclease digestion, increased half-life and/or its ability to produce increased amounts of the functional protein (e.g., enzyme) encoded thereby.

The instant invention provides RNA nanocubes, DNA nanocubes and R/DNA chimeric nanocubes comprising one or more functionalities. The multifunctional RNA nanocubes are suitable for therapeutic or diagnostic use in a number of diseases or disorders.

One aspect of the present invention relates to double-stranded RNA (dsRNA) agent capable of inhibiting the expression of a target gene. The sense strand of the dsRNA agent comprises at least one thermally destabilizing nucleotide, and at least one said thermally destabilizing nucleotide occurring at a site opposite to the seed region (positions 2-8) of the antisense strand; and the antisense strand of the dsRNA agent comprises at least two modified nucleotides that provide the nucleotide a steric bulk that is less than or equal to the steric bulk of a 2′-OMe modification, wherein said modified nucleotides are separated by 11 nucleotides in length. Other aspects of the invention relates to pharmaceutical compositions comprising these dsRNA agents suitable for therapeutic use, and methods of inhibiting the expression of a target gene by administering these dsRNA agents, e.g., for the treatment of various disease conditions.

The present invention relates to RNAi constructs and their use in gene silencing. RNAi constructs associated with the invention contain a double stranded region connected to a single stranded region of phosphorothioate modified nucleotides.