Breast cancer related protein, gene encoding the same, and method of diagnosing breast cancer using the protein and gene

Abstract

An isolated protein having an amino acid sequence of SEQ ID No. 4 and having an activity inducing apoptosis, and a gene encoding the same are provided. Also, a microarray having a substrate on which the gene or fragment thereof is immobilized is provided. Also, a method of diagnosing breast cancer using an antibody specifically binding to the protein and a method of diagnosing breast cancer by determining whether the gene is expressed in a cell or not, are provided.

1 . An isolated protein comprising: 
 an amino acid sequence of SEQ ID No. 4, wherein the protein is specifically expressed in a breast cancer cell.    
     
     
         2 . The isolated protein of  claim 1 , which is associated with apoptosis.  
     
     
         3 . The isolated protein of  claim 1 , which increases expression p53, p21, or a combination comprising one or more of the foregoing proteins in a cell.  
     
     
         4 . The isolated protein of  claim 1 , further comprising a heterologous polypeptide fused thereto.  
     
     
         5 . A method of detecting the presence or absence of a breast cancer in a test sample, the method comprising: 
 contacting an isolated anti-BCRP antibody with a polypeptide sample isolated from breast tissue from a human, wherein the anti-BCRP antibody specifically interacts with the polypeptide of SEQ ID NO:1; and    detecting any anti-BCRP-antibody-protein complexes that are formed, wherein an increase in anti-BCRP-antibody-protein complexes compared to a polypeptide sample isolated from normal breast cells indicates the presence of the breast cancer in the test sample.    
     
     
         6 . The method of  claim 4 , wherein the increase in anti-BCRP-antibody protein complexes compared to a polypeptide sample isolated from normal breast cells is about a 3% increase.  
     
     
         7 . A recombinant expression vector comprising: 
 a polynucleotide encoding a protein of  claim 1  operably linked to expression control sequences.    
     
     
         8 . The recombinant expression vector of  claim 7 , wherein the polynucleotide encoding a protein of  claim 1  comprises SEQ ID NO. 3.  
     
     
         9 . The recombinant expression vector of  claim 7 , wherein the polynucleotide is operatively linked to a tag sequence.  
     
     
         10 . A polynucleotide or a complementary polynucleotide thereof for a diagnosis or treatment of breast cancer, comprising: 
 about 10 to about 100 continuous nucleotides derived from a polynucleotide having a nucleotide sequence of SEQ ID No. 3.    
     
     
         11 . The polynucleotide of  claim 10 , further comprising about 20 to about 100 contiguous nucleotides.  
     
     
         12 . A microarray for the diagnosis of breast cancer, comprising: 
 a substrate, the substrate comprising a plurality of addresses, wherein at least one address comprises a polynucleotide according to  claim 10 .    
     
     
         13 . A kit for the diagnosis of breast cancer, comprising: 
 a polynucleotide of  claim 10;     a reagent suitable for performing a detection method; and    instructions for use thereof.    
     
     
         14 . A method of detecting the presence or absence of breast cancer, the method comprising 
 obtaining a breast tissue test sample from a subject; and    determining an expression level of a protein of  claim 1  in the breast tissue test sample,    wherein an elevated expression level of the protein of  claim 1  in the breast tissue test sample compared to an expression level of the protein of  claim 1  in a sample of normal breast tissue indicates the presence of breast cancer in the breast tissue test sample.    
     
     
         15 . The method of  claim 14 , wherein the expression level of the protein of  claim 1  in the breast tissue test sample is greater than or equal to about 2-fold higher than the expression level of the protein of  claim 1  in the sample of normal breast tissue.  
     
     
         16 . The method of  claim 14 , wherein determining the expression level is determined by northern blotting or electrophoresis.  
     
     
         17 . The method of  claim 14 , wherein determining comprises: 
 isolating total RNA from the breast tissue test sample;    performing reverse-transcription-polymerase chain reaction on the total RNA with a primer comprising 10 or more contiguous nucleotides of SEQ ID NO. 3; and    quantifying the product produced.