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Updated: Jul 16, 2026

Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1
08:53

Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1

Published on: February 17, 2011

Induction of GADD45 and JNK/SAPK-dependent apoptosis following inducible expression of BRCA1

D P Harkin1, J M Bean, D Miklos

  • 1Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown 02129, USA.

Cell
|June 15, 1999
PubMed

Insights

The breast cancer gene BRCA1 regulates DNA damage response. Its induction activates the JNK/SAPK pathway, leading to apoptosis via the GADD45 gene, independent of p53.

Area of Science:

  • Molecular Biology
  • Genetics
  • Cancer Research

Background:

  • The BRCA1 gene is crucial for DNA damage repair and transcriptional regulation.
  • Understanding BRCA1's downstream targets is key to elucidating its role in cancer susceptibility.

Purpose of the Study:

  • To identify downstream target genes of BRCA1.
  • To investigate the signaling pathways involved in BRCA1-mediated apoptosis.

Main Methods:

  • Established inducible BRCA1 expression cell lines.
  • Utilized high-density oligonucleotide arrays for gene expression profiling.
  • Analyzed gene expression changes post-BRCA1 induction.

Main Results:

  • Identified GADD45 as a major downstream target of BRCA1.
  • Demonstrated BRCA1 induction activates the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) pathway.
  • Observed p53-independent induction of GADD45 and JNK/SAPK activation.

Conclusions:

  • BRCA1 regulates the DNA damage-responsive gene GADD45.
  • BRCA1-induced apoptosis involves the JNK/SAPK signaling pathway.
  • This pathway operates independently of p53, offering insights into breast cancer mechanisms.

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