Compositions and methods for inhibiting expression of a target gene

A method of inhibiting the expression of a target gene in a cell, the method comprising:

• (a) introducing into the cell a double-stranded ribonucleic acid (dsRNA), wherein the dsRNA comprises a complementary RNA strand and a sense RNA strand, wherein the sense RNA strand comprises a nucleotide sequence which is substantially identical to at least a part of the target gene, wherein the complementary RNA strand comprises a complementary nucleotide sequence which is complementary to an mRNA transcript of a portion of the target gene, wherein the complementary RNA strand comprises a 3′-end and a 5′-end, wherein the 3′-end has a nucleotide overhang of 1 to 4 nucleotides and wherein the 5′-end is blunt, and wherein the dsRNA is no more than 49 nucleotides in length;
• and
• (b) maintaining the cell produced in step (a) for a time sufficient to obtain degradation of the mRNA transcript of the target gene, thereby inhibiting expression of the target gene in the cell.

A pharmaceutical composition for inhibiting the expression of a target gene in a mammal, comprising:

• (a) a double-stranded ribonucleic acid (dsRNA), wherein the dsRNA comprises a complementary RNA strand and a sense RNA strand, wherein the sense RNA strand comprises a nucleotide sequence which is substantially identical to at least a part of the target gene, wherein the complementary RNA strand comprises a complementary nucleotide sequence which is complementary to an mRNA transcript of a portion of the target gene, wherein the complementary RNA strand comprises a 3′-end and a 5′-end, wherein the 3′-end has a nucleotide overhang of 1 to 4 nucleotides and wherein the 5′-end is blunt, and wherein the dsRNA is no more than 49 nucleotides in length;
• and
• (b) a pharmaceutically acceptable carrier.

A method for treating a disease caused by the expression of a target gene in a mammal, which comprises administering a pharmaceutical composition comprising a double-stranded ribonucleic acid (dsRNA) and a pharmaceutically acceptable carrier, wherein the dsRNA comprises a complementary RNA strand and a sense RNA strand, wherein the sense RNA strand comprises a nucleotide sequence which is substantially identical to at least a part of the target gene, wherein the complementary RNA strand comprises a complementary nucleotide sequence which is complementary to an mRNA transcript of a portion of the target gene, wherein the complementary RNA strand comprises a 3′-end and a 5′-end, wherein the 3′-end has a nucleotide overhang of 1 to 4 nucleotides and wherein the 5′-end is blunt, and wherein the dsRNA is no more than 49 nucleotides in length.