title: The presence of anti-GRP78 antibodies in the serum of patients with colorectal carcinoma: a potential biomarker for early cancer detection.
abstract: BACKGROUND
  The identification of new biomarkers is required for early diagnosis of colorectal carcinoma patients (CRC), since about 20% of these patients are initially diagnosed with a distant metastatic disease. GRP78, a heat shock protein, functions also as a cell surface signaling receptor of cells under physiological stress. GRP78 was found to be expressed on the cell surface of various tumor cells. The presence of autoantibodies to GRP78 in cancer patient's serum was found to be correlated with a poor prognosis. In this study we aimed to identify anti-GRP78 antibodies in the serum of 85 patients diagnosed by colonoscopy, as an early detection biomarker.
  
  
  METHODS
  We developed an ELISA assay with recombinant GRP78 immobilized on 96-well culture plates and used an anti-IgG antibody to measure the sole anti-GRP78 IgGs.
  
  
  RESULTS
  Testing for anti-GRP78 showed a significant increase in antibody titer in patients with a polyp and in CRC patients (p&lt;0.001) compared to healthy subjects.
  
  
  CONCLUSIONS
  This is the first study showing the presence of anti-GRP78 at the very early stages of CRC.
authors.affiliation: 1 Felsenstein Medical Research Center, Tel Aviv University, Sackler Faculty of Medicine, Beilinson Campus, Petah-Tikva - Israel.
authors.forename: Annat
authors.initials: A
authors.lastname: Raiter
authors.forename: Alexander
authors.initials: A
authors.lastname: Vilkin
authors.forename: Rachel
authors.initials: R
authors.lastname: Gingold
authors.forename: Zohar
authors.initials: Z
authors.lastname: Levi
authors.forename: Marisa
authors.initials: M
authors.lastname: Halpern
authors.forename: Yaron
authors.initials: Y
authors.lastname: Niv
authors.forename: Britta
authors.initials: B
authors.lastname: Hardy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D014408:Biomarkers, Tumor / Q000097:blood* / Q000276:immunology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D055088:Early Detection of Cancer; D000091342:Endoplasmic Reticulum Chaperone BiP; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006360:Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000276:immunology; D008875:Middle Aged; D011379:Prognosis; D015398:Signal Transduction / Q000276:immunology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001323:Autoantibodies; D014408:Biomarkers, Tumor; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; C048844:anti-IgG