Modifications of apoptin

Abstract

Phosphorylated Apoptin is described. Apoptin is tumor-specifically phosphorylated and part of the Apoptin apoptotic pathway in tumor cells is elucidated. New therapeutic possibilities, for example, novel therapeutic compounds that can work alone or, sequentially to, or jointly with other known compounds. Also, the use of tumor-specifically phosphorylation of Apoptin for diagnostic purposes is described. Such a diagnostic purpose can, for example, be a method for detecting the presence of cancer cells or cells that are cancer prone or a method to identify a putative cancer inducing agent or a method for the in vitro treatment effect of Apoptin on tumor cells by testing the phosphorylation state of Apoptin. Even more, the invention provides possibilities to further elucidate the apoptotic pathway and to identify for example crucial mediators of phosphorylation in human tumor cells. Interfering with such a mediator could provide new anti-cancer therapies.

1 . An isolated or recombinant phosphorylated Apoptin or functional fragment thereof. 
     
     
         2 . The isolated or recombinant phosphorylated Apoptin of  claim 1  or functional fragment thereof wherein the Apoptin is tumor-specifically phosphorylated. 
     
     
         3 . The isolated or recombinant phosphorylated Apoptin of  claim 2  or functional fragment thereof wherein the isolated or recombinant phosphorylated Apoptin is phosphorylated on a threonine residue of Apoptin, which threonine residue, in the Apoptin of SEQ ID NO:1, is located between amino acid 100 and amino acid 121 of SEQ ID NO:1. 
     
     
         4 . The isolated or recombinant phosphorylated Apoptin of  claim 3  or functional fragment thereof, wherein the isolated or recombinant phosphorylated Apoptin is phosphorylated on a threonine residue, which threonine residue, in the Apoptin of SEQ ID NO:1, resides at amino acid position 106 and/or 107 and/or 108 of SEQ ID NO:1. 
     
     
         5 . A vector comprising a nucleic acid encoding Apoptin or functional fragment thereof, which Apoptin can be phosphorylated, the vector further comprising:
 a nucleic acid molecule encoding a kinase capable of phosphorylating the Apoptin or functional fragment thereof.   
     
     
         6 . A gene delivery vehicle comprising the vector of  claim 5 . 
     
     
         7 . A host cell comprising the vector of  claim 5 . 
     
     
         8 . An isolated or synthetic antibody or functional fragment thereof specifically recognizing the phosphorylated Apoptin of  claim 1 . 
     
     
         9 . An immunoassay comprising the antibody of  claim 8 . 
     
     
         10 . A nucleic acid sequence encoding the antibody of  claim 8 . 
     
     
         11 . A vector comprising the nucleic acid sequence of  claim 10 . 
     
     
         12 . A host cell comprising the vector of  claim 11 . 
     
     
         13 . (canceled) 
     
     
         14 . A method for detecting the presence of cancer cells or cells that are cancer prone in a sample of cells, the method comprising:
 providing a cell lysate of cells from the sample of cells with Apoptin or a functional fragment thereof which Apoptin or a functional fragment thereof can be phosphorylated; and   determining a phosphorylation state of the Apoptin or a functional fragment thereof.   
     
     
         15 . A method for identifying a putative cancer-inducing agent, the method comprising:
 interacting a sample of cells with the putative cancer-inducing agent;   detecting the presence of cancer cells or cells that are cancer prone in a sample of cells by providing a cell lysate of cells from the sample of cells with Apoptin or a functional fragment thereof which Apoptin or a functional fragment thereof can be phosphorylated; and   determining the phosphorylation state of the Apoptin or a functional fragment thereof.   
     
     
         16 . A method for testing an in vitro treatment effect of Apoptin on tumor cells, the method comprising:
 providing a cell lysate of tumor cells with Apoptin or functional fragment thereof which can be phosphorylated; and   determining a phosphorylation state of the Apoptin.   
     
     
         17 . The method according to  claim 14 , wherein the Apoptin further comprises a fusion protein. 
     
     
         18 . A kit for:
 a) detecting the presence of cancer cells or cells that are cancer prone; or   b) testing the in vitro treatment effect of Apoptin on tumor cells;   the kit comprising the antibody of  claim 8 .   
     
     
         19 . (canceled) 
     
     
         20 . A pharmaceutical composition comprising:
 the phosphorylated Apoptin of  claim 2 .   
     
     
         21 .- 24 . (canceled) 
     
     
         25 . A method for treating a subject having a disease wherein enhanced cell proliferation or decreased cell death is observed, the method comprising:
 treating the subject with the pharmaceutical composition of  claim 20 .