Epha3 and multi-valent targeting of tumors

Abstract

Provided herein is a construct comprising, in combination: an EphA3, EphA2 and/or EphB2 binding ligand; and at least one effector molecule. In some embodiments, the at least one effector molecule comprises a therapeutic agent, a nanoparticle, a detectable group, a lipid, or a liposome. In some embodiments, the construct is a fusion protein and/or a covalent conjugate. Further provided is a construct comprising, in combination: a ligand that binds to EphA2, EphA3 and/or EphB2; a ligand that binds to IL-13Rα2; and at least one effector molecule. Also provided are methods of use thereof for treating cancer.

What is claimed is: 
     
         1 . A construct comprising, in combination:
 a ligand that binds to EphA2, EphA3, and EphB2; and   at least one effector molecule.   
     
     
         2 . The construct of  claim 1 , wherein said construct is a fusion protein and/or a covalent conjugate. 
     
     
         3 . The construct of  claim 1 , wherein said ligand is eA5, a mutant of eA5, or an EphA2, EphA3 and EphB2 binding fragment thereof. 
     
     
         4 . The construct of  claim 3 , wherein said eA5, mutant of eA5, or EphA2, EphA3 and EphB2 binding fragment thereof is glycosylated. 
     
     
         5 . The construct of  claim 1 , wherein said at least one effector molecule comprises a diphtheria toxin or a  Pseudomonas  exotoxin A. 
     
     
         6 . The construct of  claim 1 , wherein said construct further comprises:
 a cytosol localization element covalently coupled between said ligand and said at least one effector molecule; and   a subcellular compartment localization signal element covalently coupled between said ligand and said at least one effector molecule.   
     
     
         7 . The construct of  claim 6 , wherein said subcellular compartment localization signal element is a nuclear localization element or a lysosomal localization element. 
     
     
         8 . A construct of  claim 1 , wherein said construct has the formula, from N terminus to C terminus, selected from the group consisting of:
   A-B-C-D-E,     E-D-C-B-A,     A-B-D-C-E; and     E-C-D-B-A,   
       wherein:
 A is said ligand that binds to EphA2, EphA3 and EphB2; 
 B is a linker; 
 C is a cytosol localization element; 
 D is optionally present and is a subcellular compartment localization signal element; and 
 E is said at least one effector molecule. 
 
     
     
         9 . The construct of  claim 8 , wherein each of A, C, and D, and optionally B and E, is a protein or peptide. 
     
     
         10 . The construct of  claim 8 , wherein E is a toxin or an amphipathic antimicrobial peptide. 
     
     
         11 . The construct of  claim 10 , wherein E is an amphipathic antimicrobial peptide comprising a sequence selected from the group consisting of: (KLAKLAK) 2 ; (KLAKKLA) 2 ; (KAAKKAA) 2  and (KLGKKLG) 2 . 
     
     
         12 . The construct of  claim 8 , wherein D is present and is a nuclear localization element and wherein E is a radiopharmaceutical or a chemotherapeutic agent. 
     
     
         13 . A method of detecting EphA2, EphA3 and/or EphB2 expressing cells, comprising administering said construct of  claim 1  to a cell or group of cells, wherein said construct comprises a detectable group, and detecting said detectable group. 
     
     
         14 . A method of delivering at least one effector molecule to a cell of interest, comprising:
 contacting the construct of  claim 1  to a cell of interest under conditions in which said construct is internalized therein.   
     
     
         15 . The method of  claim 14 , wherein said effector molecule is delivered to a subcellular compartment. 
     
     
         16 . The method of  claim 14 , wherein said subcellular compartment is the nucleus. 
     
     
         17 . A polypeptide comprising a mutant eA5, or an EphA2, EphA3 and/or EphB2 binding fragment thereof, or a nucleic acid encoding a polypeptide comprising a mutant eA5, or an EphA2, EphA3 and/or EphB2 binding fragment thereof. 
     
     
         18 . The polypeptide or nucleic acid of  claim 17 , wherein the mutant eA5 comprises a P123A, S125A and/or G127A mutation.