Method and medicament for inhibiting the expression of a given gene
The invention relates to an isolated RNA that mediates RNA interference of an mRNA to which it corresponds and a method of mediating RNA interference of mRNA of a gene in a cell or organism using the isolated RNA.
1 . An isolated double stranded RNA (dsRNA) comprising two complementary oligoribonucleotide strands, wherein the dsRNA is 15 to 21 base pairs in length, wherein one strand of the dsRNA is complementary to an RNA transcript of at least part of a mammalian target gene and the other strand of the dsRNA is complementary to the first strand, and wherein said dsRNA is capable of specifically inhibiting the expression of the mammalian target gene.
2 . The dsRNA of claim 1 , wherein at least one of said strands comprises at least one chemically modified nucleotide.
3 . The dsRNA of claim 2 , wherein said chemically modified nucleotide is a 2′-modified nucleotide.
4 . The dsRNA of claim 3 , wherein said 2′ modified nucleotide is a 2′-methyl substituted nucleotide.
5 . The dsRNA of claim 3 , wherein said 2′ modified nucleotide is a 2′-amino substituted nucleotide.
6 . The dsRNA of claim 3 , wherein said chemically modified nucleotide is a locked nucleotide.
7 . The dsRNA of claim 1 , wherein inhibiting the expression of said target gene further comprises inhibiting expression at a concentration of the dsRNA that is lower by one order of magnitude than a concentration required for a corresponding single-stranded oligoribonucleotide to inhibit expression.
8 . The dsRNA of claim 1 , wherein the dsRNA is enclosed by a micellar structure.
9 . The dsRNA of claim 8 , wherein the micellar structure comprises a liposome.
10 . The dsRNA of claim 1 , wherein the ends of the dsRNA are modified in order for the dsRNA to counteract degradation.
11 . The dsRNA of claim 1 , wherein the two complementary strands are fully complementary to each other.
12 . The dsRNA of claim 1 , wherein said dsRNA is capable of specifically inhibiting the expression of the mammalian target gene using dsRNA-mediated interference.
13 . The dsRNA of claim 1 , wherein only one nucleotide of at least one of the oligoribonucleotide strands is a chemically modified nucleotide.
14 . A method for inhibiting expression of a target gene, comprising:
a) introducing into a mammalian cell an isolated double stranded RNA (dsRNA) comprising two complementary oligoribonucleotide strands, wherein one strand of the dsRNA is complementary to an RNA transcript of at least part of the target gene and the other strand of the dsRNA is complementary to the first strand, and wherein the dsRNA is 15 to 21 base pairs in length; and
b) maintaining the cell produced in step a) for a time sufficient to obtain degradation of an RNA transcript of the target gene, thereby inhibiting the expression of said target gene.
15 . The method of claim 14 , wherein at least one of said strands comprises at least one chemically modified nucleotide.
16 . The method of claim 15 , wherein said chemically modified nucleotide is a 2′-modified nucleotide.
17 . The method of claim 15 , wherein said 2′ modified nucleotide is a 2′-methyl substituted nucleotide.
18 . The method of claim 15 , wherein said 2′ modified nucleotide is a 2′-amino substituted nucleotide.
19 . The method of claim 15 , wherein said chemically modified nucleotide is a locked nucleotide.
20 . The method of claim 14 , wherein inhibiting the expression of said target gene further comprises inhibiting expression at a concentration of the dsRNA that is lower by one order of magnitude than a concentration required for a corresponding single-stranded oligoribonucleotide to inhibit expression.
21 . The method of claim 14 , wherein the dsRNA is enclosed by a micellar structure.
22 . The method of claim 21 , wherein the micellar structure comprises a liposome.
23 . The method of claim 14 , wherein the ends of the dsRNA are modified in order for the dsRNA to counteract degradation.
24 . The method of claim 14 , wherein the two complementary strands are fully complementary to each other.
25 . The method of claim 14 , wherein said dsRNA specifically inhibits the expression of the target gene using dsRNA-mediated interference.
26 . The method of claim 14 , wherein only one nucleotide of at least one of the oligoribonucleotide strands is a chemically modified nucleotide.