Tumor Suppressor p53 Is Required To Modulate BRCA1 Expression

AUTOR(ES)

Arizti, Paz

FONTE

American Society for Microbiology

RESUMO

Individuals carrying mutations in BRCA1 or p53 genes are predisposed to a variety of cancers, and both tumor suppressor genes have been implicated in DNA damage response pathways. We have analyzed a possible functional link between p53 and BRCA1 genes. Here we show that BRCA1 expression levels are down-regulated in response to p53 induction in cells that undergo either growth arrest, senescence, or apoptosis. Physiological stimuli, such as exposure to DNA-damaging agents, also result in negative regulation of BRCA1 levels in a p53-dependent manner prior to causing cell cycle arrest. Nuclear run-on experiments and luciferase reporter assays demonstrate that the changes in BRCA1 expression are mainly due to transcriptional repression induced by p53. In conclusion, the data show that BRCA1 expression levels are controlled by the presence and activity of wild-type p53 and suggest the existence of an intracellular p53/BRCA1 pathway in the response of cells to stress conditions.

Documentos Relacionados

• BRCA1 regulates p53-dependent gene expression
• Accumulation of p53 protein is frequent in ovarian cancers associated with BRCA1 and BRCA2 germline mutations.
• Structure of the 53BP1 BRCT region bound to p53 and its comparison to the Brca1 BRCT structure
• The expression of the KAI1 gene, a tumor metastasis suppressor, is directly activated by p53
• E1A signaling to p53 involves the p19ARF tumor suppressor