| 摘要 |
A composition and method are provided by which double-stranded RNA containing small interfering RNA nucleotide sequences is introduced into specific cells and tissues for the purpose of inhibiting gene expression and protein production in those cells and tissues. Intracellular introduction of the small interfering RNA nucleotide sequences is accomplished by the internalization of a target cell specific ligand to which the double-stranded RNA containing a small interfering RNA nucleotide sequence is conjugated. The ligand is specific to a unique target cell surface antigen. The ligand is either spontaneously internalized after binding to the cell surface antigen. Internalization is also facilitated by the binding of an RNA binding protein to the double-stranded RNA. If the unique cell surface antigen is not naturally internalized after binding to its ligand, internalization is promoted by the incorporation of an arginine-rich peptide, or other membrane permeable peptide, into the structure of the ligand or attachment of such a peptide to the ligand. The composition and method are practiced in whole living mammals, as well as cells living in tissue culture. The dsRNA is then hydrolyzed by Dicer, an RNAse III-like ribonuclease, thereby releasing siRNA which silences the target gene. Inhibition is nucleotide sequence specific and depends upon sequence identity of small interfering RNA with the target nucleic acid.
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