title: The potential of BORIS detected in the leukocytes of breast cancer patients as an early marker of tumorigenesis.
abstract: OBJECTIVE
  Brother of the regulator of imprinted sites (BORIS) is a novel member of the cancer-testis antigen gene family. These genes are normally expressed only in spermatocytes but abnormally activated in different malignancies, including breast cancer. The aim of this study was to investigate the expression of BORIS in the leukocytes of breast cancer patients and the correlation between BORIS levels and clinical/pathologic variables.
  
  
  METHODS
  Leukocytes were obtained from whole blood of 87 breast cancer patients and 52 donors not diagnosed with cancer. BORIS protein was detected in leukocytes by immunohistochemical staining; the immunoreactivity score (IRS) of each sample was determined. Additionally, BORIS expression was assessed by Western blot analysis and real-time reverse transcription-PCR.
  
  
  RESULTS
  We describe significantly high levels of BORIS (IRS = 4.25 +/- 0.034) in a subpopulation of leukocytes, the neutrophil polymorphonuclear granulocytes, in 88.5% of breast cancer patients. Increased IRS for BORIS in these patients correlated with increased tumor size. In comparison, 19.2% samples from the control group were BORIS positive with only very low levels of BORIS (IRS = 0.25 +/- 0.009).
  
  
  CONCLUSIONS
  We report here the novel finding of BORIS expression in polymorphonuclear granulocytes of breast cancer patients. This tumor-related occurrence is a phenomenon not observed in donors with injuries and immune and inflammatory diseases. Detection of BORIS in a high proportion of patients with various types of breast tumors indicates that BORIS can be a valuable early blood marker of breast cancer. We conclude that BORIS represents a new class of cancer biomarkers different from those currently used in medical practice.
authors.affiliation: Department of Biological Sciences, University of Essex, Colchester, Essex, United Kingdom.
authors.forename: Vivien
authors.initials: V
authors.lastname: D'Arcy
authors.forename: Ziedulla K
authors.initials: ZK
authors.lastname: Abdullaev
authors.forename: Naresh
authors.initials: N
authors.lastname: Pore
authors.forename: France
authors.initials: F
authors.lastname: Docquier
authors.forename: Verónica
authors.initials: V
authors.lastname: Torrano
authors.forename: Igor
authors.initials: I
authors.lastname: Chernukhin
authors.forename: Melissa
authors.initials: M
authors.lastname: Smart
authors.forename: Dawn
authors.initials: D
authors.lastname: Farrar
authors.forename: Metodi
authors.initials: M
authors.lastname: Metodiev
authors.forename: Nelson
authors.initials: N
authors.lastname: Fernandez
authors.forename: Carlos
authors.initials: C
authors.lastname: Richard
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Delgado
authors.forename: Victor
authors.initials: V
authors.lastname: Lobanenkov
authors.forename: Elena
authors.initials: E
authors.lastname: Klenova
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D018567:Breast Neoplasms, Male / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D004268:DNA-Binding Proteins / Q000097:blood*; D005260:Female; D006801:Humans; D007154:Immune System Diseases / Q000097:blood; D007249:Inflammation / Q000097:blood; D007962:Leukocytes / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012016:Reference Values
chemical_list: D014408:Biomarkers, Tumor; C456540:CTCFL protein, human; D004268:DNA-Binding Proteins