Isolation and characterization of ECA1, a gene overexpressed in endometroid carcinomas of ovary and endometrium

Abstract

This invention provides an isolated polynucleotide encoding an ECA1 polypeptide. Also provided is the isolated ECA1 polypeptide Further provided is an antibody that specifically recognizes and binds the ECA1 polypeptide or an epitope thereof. The polynucleotides, antibodies and/or polypeptides of this invention may be components of compositions, host cells and/or gene delivery vehicles, where appropriate. In one aspect, the host cell will produce recombinant ECA1, which is further defined herein. In another aspect, the host cell is an antigen presenting cell such as a dendritic cell, and it will display an antigenic portion of the ECA1 polypeptide on its surface. The polypeptides, proteins and compositions of this invention are useful to aid in the diagnosis of a neoplastic condition of a cell of endometrioid origin. In one aspect, the method comprises detecting the presence of an overexpressed ECA1 proto-oncogene in a sample suspected of containing said cell, wherein said overexpression is indicative of the neoplastic condition of said cell. These neoplastic cells include, but are not limited to ovarian and colon carcinoma cells.

1. An isolated polynucleotide encoding an ECA1 polypeptide comprising the sequence of SEQ ID NO. 1. 
     
     
       2. An isolated gene delivery vector comprising the isolated polynucleotide of  claim 1 . 
     
     
       3. An insolated isolated host cell comprising the isolated polynucleotide of  claim 1 . 
     
     
       4. A composition comprising the polynucleotide of  claim 1 . 
     
     
       5. The insolated isolated host cell of  claim 3 , wherein the cell is an antigen presenting cell (APC). 
     
     
       6. The insolated isolated host cell of  claim 5 , wherein the antigen presenting cell (APC) is a dendritic cell. 
     
     
       7. An antibody which binds specifically to a polypeptide having the amino acid sequence of SEQ ID NO: 1. 
     
     
       8. The antibody of claim 7, wherein the antibody is selected from the group consisting of a polyclonal antibody, monoclonal antibody, Fab fragment, F(ab′) 2  fragment, single chain antibody, chimeric antibody, and humanized antibody. 
     
     
       9. The antibody of claim 7, wherein the antibody is labeled. 
     
     
       10. The antibody of claim 9, wherein the label is a radioisotope, affinity label, enzymatic label, fluorescent label, or paramagnetic atom. 
     
     
       11. The antibody of claim 10, wherein the affinity label is biotin, avidin or streptavidin. 
     
     
       12. The antibody of claim 10, wherein the enzymatic label is horseradish peroxidase or alkaline phosphatase. 
     
     
       13. The antibody of claim 10, wherein the fluorescent label is fluorescein or rhodamine. 
     
     
       14. A composition comprising the antibody of claim 7, and a carrier therefor. 
     
     
       15. The composition of claim 14, wherein the carrier is an adjuvant. 
     
     
       16. A hybridoma which produces an antibody according to claim 7. 
     
     
       17. A method for producing an antibody that specifically binds to a polypeptide having the amino acid sequence of SEQ ID NO: 1 comprising the steps of providing an animal that is known to produce antibodies; and immunizing the animal with a polypeptide having the amino acid sequence of SEQ ID NO: 1. 
     
     
       18. The method of claim 17, further comprising the steps of removing cells from the animal's spleen; and fusing the spleen cells with myeloma cells, thereby producing hybridoma cells. 
     
     
       19. The method of claim 17, wherein the animal is a mouse or rabbit. 
     
     
       20. The method of claim 17, wherein the immunizing is performed by subcutaneous or intraperitoneal injection of the polypeptide. 
     
     
       21. The method of claim 17, wherein the polypeptide is administered with an adjuvant. 
     
     
       22. The method of claim 17, wherein the polypeptide is coupled with a heterologous protein. 
     
     
       23. The method of claim 22, wherein the heterologous protein is a globulin, β-galactosidase, or keyhole limpet cyanin. 
     
     
       24. The method of claim 18, further comprising the step of screening the hybridoma cells to identify hybridoma cells that produce antibodies specific to the polypeptide. 
     
     
       25. The method of claim 24, wherein the hybridomas are screened using an enzyme-linked immunosorbent assay, western blot analysis, or radioimmunoassay.