csPCNA Isoform Antibodies And Uses Thereof

Abstract

Antibodies specifically bind only to a cancer specific proliferating cell nuclear antigen (csPCNA) isoform and not to the non-malignant proliferating cell nuclear antigen (nmPCNA) isoform. Methods and compositions to detect the presence of csPCNA isoform are disclosed.

1 . A method for reducing tumor progression in a subject, comprising:
 administering a pharmaceutically acceptable composition comprising a formulation of a therapeutically effective amount of cancer specific proliferating cell nuclear antigen (csPCNA) isoform-specific antibody that specifically binds cancer specific proliferating cell nuclear antigen (csPCNA) isoform, wherein the antibody does not bind to non-malignant proliferating cell nuclear antigen (nmPCNA), and wherein the antibody binds to an epitope of csPCNA comprising an amino acid sequence selected from LGIPEQEY (SEQ ID NO: 1), QLGIPEQEY (SEQ ID NO: 9), LGIPEQEYSCVV (SEQ ID NO: 13), LGIPEQEYSCV (SEQ ID NO: 14), and LGIPEQEYSC (SEQ ID NO: 15); and a delivery component to an individual having a tumor.   
     
     
         2 . The method of  claim 1 , wherein the formulation comprises a liposome or a nanoparticle. 
     
     
         3 . The method of  claim 1 , wherein the formulation comprises a tumor killing agent or an immune enhancing agent. 
     
     
         4 . A method of determining the presence of malignant cells, the method comprising:
 contacting a biological sample suspected of containing auto-antibodies, to a substrate comprising bound cancer specific proliferating cell nuclear antigen (csPCNA) isoform or fragments thereof, wherein the autoantibodies bind to a csPCNA isoform but do not bind to non-malignant proliferating cell nuclear antigen (nmPCNA);   providing conditions for csPCNA-auto-antibody complex formation; and   detecting the presence of the auto-antibody-csPCNA complex in the biological sample.   
     
     
         5 - 10 . (canceled)