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

摘要

The invention provides compositions and methods for selectively reducing the expression of a gene product from a desired target gene, as well as treating diseases caused by expression of the gene. The method involves introducing into the environment of a cell an amount of a double-stranded RNA (dsRNA) such that a sufficient portion of the dsRNA can enter the cytoplasm of the cell to cause a reduction in the expression of the target gene. The dsRNA has a first oligonucleotide sequence that is between 26 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 from about 19 to about 23 nucleotides is complementary to a nucleotide sequence of the RNA produced from the target gene.

主权项

1. A method for reducing expression of a target gene in a mammalian cell comprising: contacting a cell in vitro with an isolated double stranded nucleic acid in an amount sufficient to reduce expression of a target gene in said cell, wherein said double stranded nucleic acid comprises a first oligonucleotide strand comprising ribonucleotides and having a 5′ terminus and a 3′ terminus and a second oligonucleotide strand comprising ribonucleotides and having a 5′ terminus and a 3′ terminus and wherein said double stranded nucleic acid comprises blunt ends, wherein each of said first and said second strands consists of the same number of nucleotide residues and is 25-30 nucleotides, wherein the ultimate and penultimate residues of said 3′ terminus of said first strand and the ultimate and penultimate residues of said 5′ terminus of said second strand form one or two mismatched base pairs, and wherein said second oligonucleotide strand is sufficiently complementary to a target mRNA along at least 19 nucleotides of said second oligonucleotide strand length to reduce target gene expression when said double stranded nucleic acid is introduced into a mammalian cell, thereby reducing expression of the target gene in said mammalian cell.