Saposin c-dops: a novel anti-tumor agent

Abstract

Compositions and methods for treating subjects with disorders characterized by hyper-proliferating cells such as tumors and cancers are provided. The compositions comprise agents that are combinations of saposin C (or prosaposin-related polypeptides) and phospholips (or inner leaflet components). This anti-tumor agent is administered in the methods of the invention according to a dosing regimen. Administering an agent of the invention results in a positive therapeutic response in a subject with a tumor.

That which is claimed: 
     
         1 . A composition for treating cancer, comprising:
 phosphatidylserine; and   an isolated saposin C-related polypeptide, wherein the polypeptide has an amino acid sequence at least 85 percent identical to SEQ ID NO:2 and wherein the polypeptide includes amino acids 24-40 of SEQ ID NO:2;   wherein the phosphatidylserine forms a nanovesicle incorporating the polypeptide.   
     
     
         2 . The composition of  claim 1 , wherein the polypeptide has an amino acid sequence at least 90 percent identical to SEQ ID NO:2. 
     
     
         3 . The composition of  claim 1 , wherein the polypeptide has an amino acid sequence at least 95 percent identical to SEQ ID NO:2. 
     
     
         4 . The composition of  claim 1 , wherein a molar ratio of the polypeptide to the phosphatidylserine is 1:1 to 1:50. 
     
     
         5 . The composition of  claim 1 , wherein the nanovesicle has a diameter of 10 nm to 800 nm. 
     
     
         6 . The composition of  claim 1 , wherein the phosphatidylserine is selected from the group consisting of palmitoyloleoylphosphatidylserine, palmitelaidoyloleoylphosphatidylserine, myristoleoyloleoylphosphatidylserine, dilinoleoylphosphatidylserine, palmiticlinoleoylphosphatidylserine, lysophosphatidylserine, and dioleoylphosphatidylserine. 
     
     
         7 . The composition of  claim 1 , further comprising a pharmaceutically acceptable carrier. 
     
     
         8 . The composition of  claim 1 , further comprising an additional active ingredient. 
     
     
         9 . A composition comprising:
 a nanovesicle formed from a phospholipid comprising phosphatidylserine; and   an isolated saposin C-related polypeptide, wherein the polypeptide has an amino acid sequence at least 85 percent identical to SEQ ID NO:2 and wherein the polypeptide includes amino acids 24-40 of SEQ ID NO:2;   wherein the polypeptide is incorporated in the nanovesicle.   
     
     
         10 . The composition of  claim 9 , wherein the polypeptide has an amino acid sequence at least 90 percent identical to SEQ ID NO:2. 
     
     
         11 . The composition of  claim 9 , wherein the polypeptide has an amino acid sequence at least 95 percent identical to SEQ ID NO:2. 
     
     
         12 . The composition of  claim 9 , wherein a molar ratio of the polypeptide to the phosphatidylserine is 1:1 to 1:50. 
     
     
         13 . The composition of  claim 9 , wherein the nanovesicle has a diameter of 10 nm to 800 nm. 
     
     
         14 . The composition of  claim 9 , wherein the phosphatidylserine is selected from the group consisting of palmitoyloleoylphosphatidylserine, palmitelaidoyloleoylphosphatidylserine, myristoleoyloleoylphosphatidylserine, dilinoleoylphosphatidylserine, palmiticlinoleoylphosphatidylserine, lysophosphatidylserine, and dioleoylphosphatidylserine. 
     
     
         15 . The composition of  claim 9 , further comprising a pharmaceutically acceptable carrier. 
     
     
         16 . The composition of  claim 9 , further comprising an additional active ingredient.