Decreased expression of BRCA1 accelerates growth and is often present during sporadic breast cancer progression

Nat Genet. 1995 Apr;9(4):444-50. doi: 10.1038/ng0495-444.


We have characterized expression of the familial breast and ovarian cancer gene, BRCA1, in cases of non-hereditary (sporadic) breast cancer and analyzed the effect of antisense inhibition of BRCA1 on the proliferative rate of mammary epithelial cells. BRCA1 mRNA levels are markedly decreased during the transition from carcinoma in situ to invasive cancer. Experimental inhibition of BRCA1 expression with antisense oligonucleotides produced accelerated growth of normal and malignant mammary cells, but had no effect on non-mammary epithelial cells. These studies suggest that BRCA1 may normally serve as a negative regulator of mammary epithelial cell growth whose function is compromised in breast cancer either by direct mutation or alterations in gene expression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Base Sequence
  • Breast Neoplasms / etiology
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Carcinoma in Situ / genetics
  • Cell Division / drug effects
  • Cell Division / genetics
  • DNA Primers / genetics
  • DNA, Neoplasm / genetics
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Molecular Sequence Data
  • Oligonucleotides, Antisense / genetics
  • Oligonucleotides, Antisense / pharmacology
  • Oncogenes*
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Tumor Cells, Cultured


  • DNA Primers
  • DNA, Neoplasm
  • Oligonucleotides, Antisense
  • RNA, Messenger