Method of delivering RNA interference and uses thereof

1. A method of selectively delivering a siRNA into a target cell in a subject, the method comprising

administering systemically to said subject a fusion protein-double stranded RNA complex, the complex comprising:

a) a RNA molecule comprising a double stranded RNA segment of about 15-50 base pairs in length, wherein one of one strands is complementary and the other strand identical to a RNA interference target RNA; and

b) a fusion protein, comprising (1) an antibody that binds specifically to an antigen on the surface of a target cell, and (2) a protamine protein, or fragment thereof, capable of binding to double stranded RNA without chemical conjugation;

wherein the fusion protein-double stranded RNA complex selectively binds to the antigen on the surface of the target cell and selectively initiates RNA interference in the cell.

2. The method of delivering a siRNA of claim 1 , wherein the antibody is an antibody to a viral envelope protein, a cellular receptor, or an extracellular domain of an activated receptor.

3. The method of delivering a siRNA of claim 1 , wherein the antibody is a single chain antibody, a Fab portion of an antibody or a (Fab′) 2 segment.

4. The method of claim 3 , wherein the antibody recognizes gp120 or gp160.

5. The method of claim 1 , wherein the-protamine protein, or portion thereof, is fused to the carboxyl portion of the antibody.

6. The method of claim 1 , wherein the siRNA targets mRNA encoding c-myc, VEGF, CD4, CCR5, gag, MDM2, Apex, Ku70, or ErbB2.

7. The method of claim 1 , wherein the cell is selected from the group consisting of hepatocytes, myocytes, neural cells, lipocytes, lymphocytes, macrophages, cardiac cells, endothelial cells, and epithelial cells.

8. The method of claim 1 , wherein the target cell is a malignant cell.

9. The method of claim 8 , wherein the malignant cell is selected from the group consisting of a lung cancer cell, a retinal cancer cell, a breast cancer cell, a ovarian cancer cell, a prostate cancer cell, a head and neck cancer cell, a lymphoma cell, a melanoma cell, a glioma cell, a bladder cancer cell, a genital-urinary cancer cell, a stomach cancer cell, a pancreatic cancer cell, a liver cancer cell, a kidney cancer cell, and a gastrointestinal cancer cell.

10. The method of claim 1 , wherein the subject is human.

11. The method of claim 1 , further comprising administering at least one additional fusion protein-double stranded RNA complex that interferes with an additional RNA interference target RNA within the same target cell.

12. A method of selectively delivering a siRNA into a target cell in a subject, the method comprising

administering systemically to said subject at least a first and a second fusion protein-double stranded RNA complex, each first and second complex comprising:

(a) a RNA molecule comprising a double stranded RNA segment of about 15-50 base pairs in length, wherein one of one strands is complementary and the other strand identical to a RNA interference target RNA; and

(b) a fusion protein, comprising (1) an antibody that binds specifically to an antigen on the target cell surface and (2) a protamine protein, or fragment thereof, capable of binding to double stranded RNA without chemical conjugation;

wherein the fusion protein-double stranded RNA complex binds to an antigen site on said target cell surface and selectively initiates RNA interference against at least a first and second target RNA within the same target cell.

13. A method of delivering a siRNA into a target primary cell, the method comprising contacting the target primary cell with a fusion protein-double stranded RNA complex comprising:

(a) a RNA molecule comprising a double stranded RNA segment, wherein one of the strands is complementary and the other strand identical to a RNA interference target RNA; and

(b) a recombinant protein comprising (1) an antibody that binds specifically to an antigen on the target primary cell surface, and (2) a protamine protein, or fragment thereof, capable of binding to double stranded RNA without chemical conjugation;

wherein said recombinant protein-double stranded RNA complex binds specifically to an antigen on the target primary cell; and

wherein said recombinant protein-double stranded RNA complex selectively initiates RNA interference within the target primary cell.

14. A method of delivering a siRNA into a target primary cell, the method comprising contacting the target primary cell with a fusion protein-double stranded RNA complex comprising:

(a) a RNA molecule comprising a double stranded RNA segment of about 15-50 base pairs in length, wherein one of the strands is complementary and the other strand identical to a RNA interference target RNA; and

(b) a fusion protein comprising (1) an antibody that binds specifically to an antigen on the target primary cell surface, and (2) a protamine protein, or fragment thereof, capable of binding to double stranded RNA without chemical conjugation;

wherein the double stranded RNA segment binds the fusion protein without chemical conjugation and wherein said fusion protein-double stranded RNA complex binds specifically to an antigen on the target primary cell; and

wherein said fusion protein-double stranded RNA complex selectively initiates RNA interference within the target primary cell.

15. A method of selectively delivering a siRNA into a target cell in a subject, the method comprising

administering systemically to said subject a fusion protein-double stranded RNA complex, the complex comprising:

a) a RNA molecule comprising a double stranded RNA segment of about 15-50 base pairs in length, wherein one of one strands is complementary and the other strand identical to a RNA interference target RNA; and

b) a fusion protein, comprising (1) an antibody that binds specifically to an antigen on the surface of a target cell, and (2) a full-length protamine protein, or fragment thereof, capable of binding to double stranded RNA without chemical conjugation, wherein the fragment thereof is encoded by a nucleic acid having a 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:6, and nucleic acids 10-76 of SEQ ID NO:1; and

wherein the fusion protein-double stranded RNA complex selectively binds to the antigen on the surface of the target cell and selectively initiates RNA interference in the cell.