Colon cancer marker

Abstract

The invention provides a cDNA which encodes a colon cancer marker. It also provides for the use of the cDNA, fragments, complements, and variants thereof and of the encoded protein, portions thereof and antibodies thereto for diagnosis and treatment of colon disorders, particularly colon cancer and polyps. The invention additionally provides expression vectors and host cells for the production of the protein and a transgenic model system.

What is claimed is:  
     
         1 . A purified protein comprising a polypeptide selected from: 
 a) an amino acid sequence of SEQ ID NO: 1;    b) a biologically active portion of SEQ ID NO: 1;    c) an antigenic epitope of the protein of SEQ ID NO: 1, and    d) an amino acid sequence having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 1.    
     
     
         2 . A purified protein comprising an amino acid sequence of SEQ ID NO: 1.  
     
     
         3 . A composition comprising the protein of  claim 1  and a labeling moiety.  
     
     
         4 . A composition comprising the protein of  claim 1  and a pharmaceutical carrier.  
     
     
         5 . A substrate upon which the protein of  claim 1  is immobilized.  
     
     
         6 . An array element comprising the protein of  claim 1 .  
     
     
         7 . A method for detecting expression of a protein having the amino acid sequence of SEQ ID NO: 1 in a sample, the method comprising: 
 a) performing an assay to determine the amount of the protein of  claim 2  in a sample; and    b) comparing the amount of protein to standards, thereby detecting expression of the protein in the sample.    
     
     
         8 . The method of  claim 7  wherein the sample is colon tissue.  
     
     
         9 . The method of  claim 7  wherein the protein is differentially expressed when compared with the standard and is diagnostic of a colon cancer.  
     
     
         10 . A method for using a protein to screen a plurality of molecules and compounds to identify at least one ligand, the method comprising: 
 a) combining the protein of  claim 1  with a plurality of molecules and compounds under conditions to allow specific binding; and    b) detecting specific binding, thereby identifying a ligand that specifically binds the protein.    
     
     
         11 . The method of  claim 10  wherein the molecules and compounds are selected from agonists, antagonists, DNA molecules, small drug molecules, immunoglobulins, inhibitors, mimetics, peptides, peptide nucleic acids, pharmaceutical agent, proteins, and RNA molecules.  
     
     
         12 . A method for using a protein to identify an antibody that specifically binds the protein having the amino acid sequence of SEQ ID NO: 1 comprising: 
 a) contacting a plurality of antibodies with the protein of  claim 1  under conditions to allow specific binding, and    b) detecting specific binding between an antibody and the protein, thereby identifying an antibody that specifically binds the protein.    
     
     
         13 . The method of  claim 12 , wherein the plurality of antibodies are selected from a polyclonal antibody, a monoclonal antibody, a chimeric antibody, a recombinant antibody, a bispecific antibody, a multispecific antibody, a humanized antibody, a single chain antibody, a Fab fragment, an F(ab′) 2  fragment, an Fv fragment; and an antibody-peptide fusion protein.  
     
     
         14 . A method of using a protein to prepare and purify a polyclonal antibody comprising: 
 a) immunizing a animal with a protein of  claim 1  under conditions to elicit an antibody response;    b) isolating animal antibodies;    c) attaching the protein to a substrate;    d) contacting the substrate with isolated antibodies under conditions to allow specific binding to the protein;    e) dissociating the antibodies from the protein, thereby obtaining purified polyclonal antibodies.    
     
     
         15 . A method of using a protein to prepare a monoclonal antibody comprising: 
 a) immunizing a animal with a protein of  claim 1  under conditions to elicit an antibody response;    b) isolating antibody-producing cells from the animal;    c) fusing the antibody-producing cells with immortalized cells in culture to form monoclonal antibody producing hybridoma cells;    d) culturing the hybridoma cells; and    e) isolating from culture monoclonal antibody that specifically binds the protein.    
     
     
         16 . A method for using a protein to diagnose a colon cancer comprising: 
 a) performing an assay to quantify the expression of the protein of  claim 1  in a sample;    b) comparing the expression of the protein to standards, thereby diagnosing a colon cancer.    
     
     
         17 . A method for testing a molecule or compound for effectiveness as an agonist comprising: 
 a) exposing a sample comprising the protein of  claim 1  to the molecule or compound, and    b) detecting agonist activity in the sample.    
     
     
         18 . A method for testing a molecule or compound for effectiveness as an antagonist, the method comprising: 
 a) exposing a sample comprising the protein of  claim 1  to a molecule or compound, and    b) detecting antagonist activity in the sample.    
     
     
         19 . An isolated antibody that specifically binds a protein having the amino acid sequence of SEQ ID NO: 1.  
     
     
         20 . A polyclonal antibody produced by the method of  claim 14 .  
     
     
         21 . A monoclonal antibody produced by the method of  claim 15 .  
     
     
         22 . A method for using an antibody to detect expression of a protein in a sample, the method comprising: 
 a) combining the antibody of  claim 19  with a sample under conditions which allow the formation of antibody:protein complexes; and    b) detecting complex formation, wherein complex formation indicates expression of the protein in the sample.    
     
     
         23 . The method of  claim 22  wherein the sample is colon tissue.  
     
     
         24 . The method of  claim 22  wherein complex formation is compared with standards and is diagnostic of a colon cancer.  
     
     
         25 . A method for using an antibody to immunopurify a protein comprising: 
 a) attaching the antibody of  claim 19  to a substrate,    b) exposing the antibody to a sample containing protein under conditions to allow antibody:protein complexes to form,    c) dissociating the protein from the complex, and    d) collecting the purified protein.    
     
     
         26 . A composition comprising an antibody of  claim 19  and a labeling moiety.  
     
     
         27 . A kit comprising the composition of  claim 26 .  
     
     
         28 . An array element comprising the antibody of  claim 19 .  
     
     
         29 . A substrate upon which the antibody of  claim 19  is immobilized.  
     
     
         30 . A composition comprising an antibody of  claim 19  and a pharmaceutical agent.  
     
     
         31 . The composition of  claim 30  wherein the composition is lyophilized.  
     
     
         32 . A method for using a composition to assess efficacy of a molecule or compound, the method comprising: 
 a) treating a sample containing protein with a molecule or compound;    b) contacting the protein in the sample with the composition of  claim 30  under conditions for complex formation;    c) determining the amount of complex formation; and    d) comparing the amount of complex formation in the treated sample with the amount of complex formation in an untreated sample, wherein a difference in complex formation indicates efficacy of the molecule or compound.    
     
     
         33 . A method for using a composition to assess toxicity of a molecule or compound, the method comprising: 
 a) treating a sample containing protein with a molecule or compound;    b) contacting the protein in the sample with the composition of  claim 30  under conditions for complex formation;    c) determining the amount of complex formation; and    d) comparing the amount of complex formation in the treated sample with the amount of complex formation in an untreated sample, wherein a difference in complex formation indicates toxicity of the molecule or compound.    
     
     
         34 . A method for treating a colon cancer comprising administering to a subject in need of therapeutic intervention the antibody of  claim 19 .  
     
     
         35 . A method for treating a colon cancer comprising administering to a subject in need of therapeutic intervention the antibody of  claim 21 .  
     
     
         36 . A method for treating a colon cancer comprising administering to a subject in need of therapeutic intervention the composition of  claim 30.