Methods and compositions for the specific inhibition of gene expression by double-stranded RNA

摘要

The invention is directed to compositions and methods for selectively reducing the expression of a gene product from a desired target gene in a cell, as well as for treating diseases caused by the expression of the gene. More particularly, the invention is directed to compositions that contain double stranded RNA (“dsRNA”), and methods for preparing them, that are capable of reducing the expression of target genes in eukaryotic cells. The dsRNA has a first oligonucleotide sequence that is between 25 and about 30 nucleotides in length and a second oligonucleotide sequence that anneals to the first sequence under biological conditions. In addition, a region of one of the sequences of the dsRNA having a sequence length of at least 19 nucleotides is sufficiently complementary to a nucleotide sequence of the RNA produced from the target gene to trigger the destruction of the target RNA by the RNAi machinery.

主权项

1. A nucleic acid molecule capable of reducing expression of a target gene following cleavage by human Dicer enzyme comprising:
a first oligonucleotide strand 25-30 nucleotides in length comprising RNA, a 3′ terminus and a 5′ terminus, and a second oligonucleotide strand at least 26 nucleotides in length comprising RNA, a 3′ terminus, a 5′ terminus and a nucleotide sequence that is complementary to a sequence of a target mRNA of said target gene, wherein said second strand is annealed to said first strand under biological conditions to form a duplex region of at least 25 nucleotides in length, wherein the 5′ terminus of said second strand forms a blunt end with the 3′ terminus of said first strand, wherein said second strand comprises a 1-4 nucleotide 3′-overhang with respect to the 5′ terminus of said first strand, and wherein said nucleic acid molecule is cleaved by human Dicer enzyme to facilitate incorporation of a cleavage product of said second oligonucleotide strand into RISC.