Compositions and methods for inhibiting expression of the HAMP gene
The invention relates to a double-stranded ribonucleic acid (dsRNA) for inhibiting the expression of the HAMP gene (HAMP gene), comprising an antisense strand having a nucleotide sequence which is less that 30 nucleotides in length, generally 19-25 nucleotides in length, and which is substantially complementary to at least a part of the HAMP gene. The invention also relates to a pharmaceutical composition comprising the dsRNA together with a pharmaceutically acceptable carrier; methods for treating diseases caused by HAMP gene expression and the expression of the HAMP gene using the pharmaceutical composition.
1. A double-stranded ribonucleic acid (dsRNA), wherein the dsRNA comprises an antisense strand and a sense strand, wherein each strand is less than 30 nucleotides in length, and wherein the target sequence of the dsRNA comprises the first nineteen nucleotides of SEQ ID NO:29 (GAACAUAGGUCUUGGAAUA).
2. The dsRNA of claim 1 , wherein the dsRNA comprises at least one modified nucleotide.
3. The dsRNA of claim 2 , wherein the modified nucleotide is chosen from the group of: a 2′-O-methyl modified nucleotide, a nucleotide comprising a 5′-phosphorothioate group, and a terminal nucleotide linked to a cholesteryl derivative or dodecanoic acid bisdecylamide group.
4. The dsRNA of claim 2 , wherein the modified nucleotide is chosen from the group of: a 2′-deoxy-2′-fluoro modified nucleotide, a 2′-deoxy-modified nucleotide, a locked nucleotide, an abasic nucleotide, 2′-amino-modified nucleotide, 2′-alkyl-modified nucleotide, morpholino nucleotide, a phosphoramidate, and a non-natural base comprising nucleotide.
5. The dsRNA of claim 1 , wherein the sense strand is modified as follows: GAAcAuAGGucuuGGAAuATsT (SEQ ID NO:227) and the antisense strand is modified as follows: uAuUCcAAGACCuAuGuUCTs (SEQ ID NO:244), wherein “c” indicates a 2′-O-methyl modified cytodine; “u” indicates a 2′-O-methyl modified uracil, and sT indicates a 5′-phosphorothioate modified thymidine.
6. The dsRNA of claim 1 , wherein the sense strand consists of SEQ ID NO:29 and the antisense strand consists of SEQ ID NO:65.
7. A cell comprising the dsRNA of claim 1 .
8. The cell of claim 7 wherein the cell is a liver cell.
9. A vector encoding each strand of the dsRNA of claim 1 .
10. A cell comprising the vector of claim 9 .
11. A pharmaceutical composition comprising the dsRNA of claim 1 and a pharmaceutically acceptable carrier.
12. The pharmaceutical composition of claim 11 , wherein the carrier is a lipid carrier.
13. The dsRNA of claim 1 , wherein the dsRNA is formulated in a lipid formulation.
14. The dsRNA of claim 1 , wherein the dsRNA is formulated in a liposome.
15. The dsRNA of claim 1 , wherein the dsRNA inhibits the expression of a hepcidin antimicrobial peptide (HAMP) gene in a COS-7 cell by 90% compared to a control when the dsRNA is transfected into the cell at a concentration of 50 nM.
16. The dsRNA of claim 5 , wherein the dsRNA inhibits the expression of a hepcidin antimicrobial peptide (HAMP) gene in a COS-7 cell by 88% compared to a control when the dsRNA is transfected into the cell at a concentration of 50 nM.
17. The dsRNA of claim 1 , whrerein the dsRNA is conjugated to a molecule.
18. The dsRNA of claim 17 , wherein the molecule is a ligand moiety or a non-ligand moiety.
19. A method for inhibiting the expression of a hepcidin antimicrobial peptide (HAMP) gene in a cell, the method comprising:
introducing into the cell the dsRNA of claim 1 ; and
maintaining the cell for a time sufficient to obtain degradation of the mRNA transcript of the HAMP gene, thereby inhibiting expression of the HAMP gene in the cell.
20. A method of treating or managing pathological processes mediated by hepcidin antimicrobial peptide (HAMP) expression in a patient in need thereof comprising administering to the patient an effective amount of the dsRNA of claim 1 .