Methods and compositions concerning siRNA's as mediators of RNA interference

1 . An isolated RNA of from about 5 to about 20 nucleotides that mediates RNA interference of a target mRNA.

2 . The isolated RNA of claim 1 further comprising a terminal 3′ hydroxyl group.

3 . The isolated RNA of claim 1 which is chemically synthesized RNA or an analog of a naturally occurring RNA.

4 . The isolated RNA of claim 1 , wherein the RNA is from about 12 to about 18 nucleotides in length.

5 . The isolated RNA of claim 1 , wherein the RNA is from about 14 to about 16 nucleotides in length.

6 . The isolated RNA of claim 1 , wherein the RNA is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 nucleotides in length.

7 . The isolated RNA of claim 1 , wherein the RNA is an siRNA.

8 . The isolated RNA of claim 1 , wherein the RNA is a single-stranded.

9 . The isolated RNA of claim 1 , wherein the RNA is a double-stranded.

10 . The isolated RNA of claim 9 , wherein the 3′ ends of the double stranded RNA comprises a 2, 3, 4, or 5 nucleotide overhang.

11 . The isolated RNA of claim 10 , wherein the nucleotide overhang is a 2 nucleotide overhang.

12 . The isolated RNA of claim 11 , wherein the 2 nucleotides are thymine.

13 . The isolated RNA of claim 9 , wherein the 5′ ends of the double stranded RNA comprises a 2, 3, 4, or 5 nucleotide overhang.

14 . The isolated RNA of claim 13 , wherein the nucleotide overhang is a 2 nucleotide overhang.

15 . The isolated RNA of claim 14 , wherein the 2 nucleotides are thymine.

16 . The isolated RNA of claim 1 , wherein the RNA is formulated into a pharmaceutically acceptable composition.

17 . The isolated RNA of claim 1 , wherein the RNA associates with a protein complex.

18 . The isolated RNA of claim 17 , wherein the protein complex is RNA-induced silencing complex (RISC).

19 . The isolated RNA of claim 1 , wherein the isolated RNA comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13; SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17; SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30; SEQ ID NO: 31, SEQ ID NO: 32, SEQ ID NO: 33, SEQ ID NO: 34, SEQ ID NO 35, SEQ ID NO: 36; SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, and SEQ ID NO: 54.

20 . A method of reducing expression of a target gene in a cell comprising:

a) obtaining at least one siRNA of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleotides in length; and

b) delivering the siRNA into the cell.

21 . The method of claim 20 , wherein the siRNA is 10, 11, 12, 13, 14, 15, 16, or 17 nucleotides in length.

22 . The method of claim 21 , wherein the siRNA is 12, 13, 14, or 15 nucleotides in length.

23 . The method of claim 20 , wherein the siRNA is chemically synthesized siRNA or an analog of a naturally occurring siRNA.

24 . The method of claim 20 , further comprising isolating the siRNA prior to delivery.

25 . The method of claim 20 , further comprising obtaining at least two siRNAs and delivering them into the cell.

26 . The method of claim 20 , further comprising obtaining a pool of siRNAs and delivering the pool into the cell.

27 . The method of claim 20 , wherein the cell is comprised in an organism.

28 . The method of claim 20 , wherein the cell is a human cell.

29 . The method of claim 20 , wherein multiple siRNA molecules are delivered into the cell.

30 . The method of claim 20 , wherein the siRNA comprises a terminal 3′ hydroxyl group.

31 . The method of claim 20 , wherein the siRNA is double-stranded.

32 . The method of claim 31 , wherein the 3′ ends of the double stranded siRNA comprise a 2, 3, 4, or 5 nucleotide overhang.

33 . The method claim 32 , wherein the nucleotide overhang is a 2 nucleotide overhang.

34 . The method of claim 33 , wherein the 2 nucleotides are thymine.

35 . The method of claim 31 , wherein the 5′ ends of the double stranded siRNA comprise a 2, 3, 4, or 5 nucleotide overhang.

36 . The method of claim 35 , wherein the nucleotide overhang is a 2 nucleotide overhang.

37 . The method of claim 36 , wherein the two nucleotides are thymine.

38 . The method of claim 20 , wherein the siRNA is formulated into a pharmaceutically acceptable composition.

39 . The method of claim 20 , wherein the siRNA associates with a protein complex.

40 . The method of claim 39 , wherein the protein complex is RNA-induced silencing complex (RISC).

41 . The method of claim 20 , wherein the siRNA comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13; SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17; SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30; SEQ ID NO: 31, SEQ ID NO: 32, SEQ ID NO: 33, SEQ ID NO: 34, SEQ ID NO 35, SEQ ID NO: 36; SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, and SEQ ID NO: 54.