Aptamer Compositions and Methods of Use Thereof

Abstract

An aptamer platform capable of efficiently delivering and silencing one, two or more genes in vivo or in vitro is provided. Methods of using the aptamer compositions for selectively targeting cells to down-regulate the expression of multiple genes are also provided.

I claim: 
     
         1 . An aptamer-siRNA chimera comprising:
 first and second ends, wherein the first and second ends comprise an aptamer that specifically binds a target protein; and   an siRNA construct between the first and second ends, wherein the siRNA construct is processed by cellular RNAi machinery to produce at least two different siRNAs that specifically inhibit expression of two or more different genes in a cell expressing the target protein.   
     
     
         2 . The chimera of  claim 1 , wherein at least one of the two or more different genes are survivin and EGFR and the target protein is HER2, HER3 or PSMA. 
     
     
         3 . The chimera of  claim 1 , wherein the two or more different genes are oncogenes selected from the group consisting of ABL1, ABL2, AKT1, AKT2, ATF1, BCL11A, BCL2, BCL3, BCL6, BCR, BIRC5, BRAF, CARD11, CBLB, CBLC, CCND1, CCND2, CCND3, CCNE1, CDX2, CTNNB1, DDB2, DDIT3, DDX6, DEK, EGFR, ELK4, ERBB2, ETV4, ETV6, EVI1, EWSR1, FEV, FGFR1, FGFR2, FGFR3, FGFR4, FGFR6, EGFR, FGFR1OP, FUS, GOLGA5, GOPC, HMGA1, HMGA2, HRAS, IRF4, JUN, KIT, KRAS, LCK, LMO2, MAF, MAFB, MAML2, MDM2, MET, MITF, MPL, MYB, MYC, MYCL1, MYCN, NCOA4, NFKB2, NRAS, NTRK1, NUP214, PAX8, PDGFB, PIK3CA, PIM1, PLAG1, PPARG, PTPN11, RAF1, REL, RET, ROS1, SMO, SS18, TCL1A, TET2, TFG, MLL, TLX1, TPR, and USP6. 
     
     
         4 . The chimera of  claim 1 , wherein the target protein is selected from the group consisting of CLPP, CEA, Her-2/neu, Bladder Tumor Antigen, Thyroglobulin, Alpha-fetoprotein, PSA, CA 125, CA19.9, CA 15.3, leptin, prolactin, osteopontin, IGF-II, CD98, fascin, sPIgR, EpCAM, transferrin receptor, CD44, AXL, Human matrix metalloprotease 9, VEGFR, EGFR, Her3, ICAM-1, VCAM-1, Chemokine receptors, CD3, CD4, CD8, TNFR, L (P,E) selectin, and 14-3-3. 
     
     
         5 . The chimera of  claim 3 , wherein the target protein is HER2 or HER3. 
     
     
         6 . The chimera of  claim 1 , wherein the target protein is a tumor neovascular antigen. 
     
     
         7 . A method for treating breast cancer in a subject in need thereof, comprising:
 administering to the subject an effective amount of the chimera of  claim 2 .   
     
     
         8 . A method for reducing tumor burden in a subject in need thereof comprising:
 administering to the subject an effective amount of an aptamer to induce or promote apoptosis of the tumor cells, wherein the aptamer comprises first and second ends, wherein the first and second ends comprise an aptamer that specifically binds a cell surface protein expressed by the tumor cells; and an siRNA construct between the first and second ends, wherein the siRNA construct is processed by cellular RNAi machinery of the cancer cells to produce at least one or two different siRNAs that specifically inhibit expression of one or two or more different genes in the tumor cells to promote apoptosis of the tumor cells and thereby reduce tumor burden in the subject.   
     
     
         9 . The method of  claim 8 , wherein the two or more different genes comprise EGFR and survivin. 
     
     
         10 . The method of  claim 9 , wherein the two or more different genes comprise an oncogene expressed by the cancer cell. 
     
     
         11 . A method of reducing tumor associated angiogenesis in a subject in need thereof comprising:
 administering to the subject an effective amount of the aptamer of  claim 1  to reduce tumor associated angiogenesis, wherein the first and second ends comprise an aptamer that specifically binds a cell surface protein expressed by the tumor; and wherein the siRNA construct is processed by cellular RNAi machinery of tumor to produce at least one or two different siRNAs that specifically inhibit expression of two or more different genes in the tumor, wherein the two or more different genes comprise EGFR and survivin.   
     
     
         12 . A method for treating a viral infection in a subject in need thereof comprising:
 administering to the subject an effective amount of the aptamer of  claim 1  to inhibit expression genes of the virus infecting the subject, wherein the first and second ends comprise an aptamer that specifically binds a cell surface viral protein expressed by virally infected cells; and   wherein the siRNA construct is processed by cellular RNAi machinery of the cells to produce at least two different siRNAs that specifically inhibit expression of two or more different genes of the infecting virus.   
     
     
         13 . A pharmaceutical composition comprising an effective amount of the aptamer of  claim 1 . 
     
     
         14 . The pharmaceutical composition of  claim 14 , wherein the aptamer comprises SEQ ID NOs: 31 and 33. 
     
     
         15 . A nucleic acid composition according to  FIG. 11A .