Polypeptide compounds for inhibiting angiogenesis and tumor growth

Abstract

In certain embodiments, this present invention provides polypeptide compositions, including compositions containing a modified polypeptide, and methods for inhibiting Ephrin B2 or EphB4 activity. In other embodiments, the present invention provides methods and compositions for treating cancer or for treating angiogenesis-associated diseases.

1 . An isolated soluble polypeptide comprising an amino acid sequence of an extracellular domain of an EphB4 protein, wherein the polypeptide is a monomer and binds specifically to an Ephrin B2 polypeptide. 
     
     
         2 . The polypeptide of  claim 1 , comprising a globular domain of an EphB4 protein or a sequence that is at least 90% identical to a globular domain of EphB4. 
     
     
         3 . The polypeptide of  claim 1 , comprising a sequence at least 90% identical to residues 29-197 of the amino acid sequence defined by  FIG. 65  (SEQ ID NO:10). 
     
     
         4 . The polypeptide of  claim 1 , further comprising a modification that increases serum half-life. 
     
     
         5 . The polypeptide of  claim 4 , wherein said modification comprises a polyethylene glycol group. 
     
     
         6 - 12 . (canceled) 
     
     
         13 . The polypeptide of  claim 4 , wherein said polypeptide has a serum half-life in vivo at least 50% greater than that of an unmodified EphB4 polypeptide. 
     
     
         14 . The polypeptide of  claim 4 , wherein said polypeptide has a serum half-life in vivo at least 100% greater than that of an unmodified EphB4 polypeptide. 
     
     
         15 . The polypeptide of  claim 4 , wherein the polypeptide is a fusion protein. 
     
     
         16 . The polypeptide of  claim 15 , wherein the polypeptide comprises an albumin protein or fragments thereof. 
     
     
         17 . The polypeptide of  claim 16 , wherein said albumin protein is selected from a human serum albumin (HSA) and bovine serum albumin (BSA). 
     
     
         18 . The polypeptide of  claim 16 , wherein the albumin is a naturally occurring variant. 
     
     
         19 . The polypeptide of  claim 1 , wherein the polypeptide has one or more activities selected from:
 (a) inhibition of EphrinB2 activity;   (b) inhibition of EphrinB2 kinase activity;   (c) inhibition of the interaction between EphB4 and EphrinB2;   (d) inhibition of EphB4 kinase activity;   (e) inhibition of clustering of Ephrin B2; and   (f) inhibition of clustering of EphB4.   
     
     
         20 . The polypeptide of  claim 4 , wherein the polypeptide has enhanced in vivo stability relative to the unmodified wildtype polypeptide. 
     
     
         21 . A pharmaceutical composition comprising a polypeptide of  claim 1 , and a pharmaceutically acceptable carrier. 
     
     
         22 . A method of inhibiting signaling through Ephrin B2/EphB4 pathway in a cell, comprising contacting the cell with an effective amount of a polypeptide of  claim 1 . 
     
     
         23 . A method of reducing the growth rate of a tumor, comprising administering an amount of a polypeptide of  claim 1 , sufficient to reduce the growth rate of the tumor. 
     
     
         24 . A method for treating a patient suffering from a cancer, comprising administering to the patient a polypeptide of  claim 1 . 
     
     
         25 . A method of inhibiting angiogenesis, comprising contacting a cell with a polypeptide of  claim 1 . 
     
     
         26 . A method for treating a patient suffering from an angiogenesis-associated disease, comprising administering to the patient a polypeptide of  claim 1 . 
     
     
         27 . The polypeptide of  claim 1 , wherein the polypeptide comprises one or more modified amino acid residues. 
     
     
         28 . A cosmetic composition comprising the polypeptide of  claim 1 , and a pharmaceutically acceptable carrier. 
     
     
         29 . A method of reducing the growth rate of a tumor, comprising administering an amount of a polypeptide agent sufficient to reduce the growth rate of the tumor, wherein the polypeptide agent is selected from:
 (a) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an EphB4 protein, wherein the EphB4 polypeptide is a monomer and binds specifically to an Ephrin B2 polypeptide; and   (b) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an Ephrin B2 protein, wherein the soluble Ephrin B2 polypeptide is a monomer and binds with high affinity to an EphB4 polypeptide.   
     
     
         30 . The method of  claim 29 , wherein the tumor comprises cells expressing a higher level of EphB4 and/or EphrinB2 than noncancerous cells of a comparable tissue. 
     
     
         31 . A method for treating a patient suffering from a cancer, comprising administering to the patient a polypeptide agent selected from:
 (a) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an EphB4 protein, wherein the EphB4 polypeptide is a monomer and binds specifically to an Ephrin B2 polypeptide; and   (b) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an Ephrin B2 protein, wherein the soluble Ephrin B2 polypeptide is a monomer and binds with high affinity to an EphB4 polypeptide.   
     
     
         32 - 38 . (canceled) 
     
     
         39 . A method of inhibiting angiogenesis, comprising contacting a cell with an amount of a polypeptide agent sufficient to inhibit angiogenesis, wherein the polypeptide agent is selected from:
 (a) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an EphB4 protein, wherein the EphB4 polypeptide is a monomer and binds specifically to an Ephrin B2 polypeptide; and   (b) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an Ephrin B2 protein, wherein the soluble Ephrin B2 polypeptide is a monomer and binds with high affinity to an EphB4 polypeptide.   
     
     
         40 . A method for treating a patient suffering from an angiogenesis-associated disease, comprising administering to the patient a polypeptide agent selected from:
 (a) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an EphB4 protein, wherein the EphB4 polypeptide is a monomer and binds specifically to an Ephrin B2 polypeptide; and   (b) a soluble polypeptide comprising an amino acid sequence of an extracellular domain of an Ephrin B2 protein, wherein the soluble Ephrin B2 polypeptide is a monomer and binds with high affinity to an EphB4 polypeptide.   
     
     
         41 - 47 . (canceled)