title: Expression of BRCA1 and BRCA2 proteins and their correlation with clinical staging in breast cancer.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the level of expression of the BRCA1 and BRCA2 proteins in sporadic breast cancer cases to determine the functional role of these genes in breast carcinogenesis.
  
  
  METHODS
  Paraffin embedded histologically proven invasive breast tissue sections that were obtained from 40 patients and the adjacent normal breast tissue sections used as controls to determine breast carcinoma specific changes in the expression of BRCA1 and BRCA2 by immunohistochemistry (IHC).
  
  
  RESULTS
  Majority of the cases express either low or no detectable level of BRCA1 expression in tumor tissues in comparison with control; the decline in BRCA1 expression was found to be more prominent in advanced grade 3 disease. On the other hand, the expression of BRCA2 protein was moderate or low in breast cancer cases and its overall distribution did not show significant difference when compared with controls. Interestingly, those breast cancer cases, which were found to express low or no BRCA1 expression, demonstrated a higher protein level of BRCA2. The inverse correlation of BRCA1 and BRCA2 expression was more prominent in post-menopausal patients.
  
  
  CONCLUSIONS
  Our results demonstrate in a subset of cases that decline in BRCA1 expression that may be associated with potentially compensatory increase in BRCA2 protein, which may depend on tumor grade as well as menopausal status.
authors: Division of Molecular Oncology, Institute of Cytology and Preventive Oncology (ICMR), Noida, Uttar Pradesh, India.
authors: Suresh
authors: S
authors: Hedau
authors: Madhu
authors: M
authors: Batra
authors: Usha Rani
authors: UR
authors: Singh
authors: Alok C
authors: AC
authors: Bharti
authors: Amitabha
authors: A
authors: Ray
authors: Bhudev C
authors: BC
authors: Das
mesh_terms: D000328:Adult; D019313:BRCA1 Protein / Q000235:genetics / Q000378:metabolism*; D024682:BRCA2 Protein / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D012307:Risk Factors; D055815:Young Adult
chemical_list: D019313:BRCA1 Protein; D024682:BRCA2 Protein