Innovative Approaches for Determining the Role of BRCA2 and BRCA1 in DNA Recombinational Repair: Examination of Genetic Instability and Possible Therapeutic Uses
Abstract
We have been interested in providing direct evidence for a role for the hereditary breast cancer genes BRCA1 and BRCA2 in the repair of DNA damage, specifically chromosomal double-strand breaks, by homologous recombination. Defects in precise repair of such breaks may lead to a loss of genomic integrity and promote the steps leading to tumorigenesis. An important protein in homologous repair pathways to repair chromosome breaks is Rad51. Products of both the BRCA1 and BRCA2 genes interact with Rad51, leading us to propose that homologous repair may be defective in cells mutated for these genes. In this annual report we describe homologous gene targeting experiments in Brca2-deficient ES cells that bring in a gene conversion substrate containing green fluorescent protein gene repeats. Firstly, gene targeting is reduced albeit mildly. Secondly, repair of an induced break in the gene conversion substrate, as monitored by measuring green fluorescence within the cell, is reduced. Thirdly, in wild-type cells, we see a gene conversion defect by interfering with Rad5 1 activity by expressing a peptide from BRCA2 that is only 2% of the protein. This defect in homologous recombination in Brca2 cells, and BRCA1 cells as reported last year, may contribute to the development of early-onset breast and ovarian cancers by destabilizing the genome.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2000
- Accession Number
- ADB266387
Entities
People
- Maria Jasin
Organizations
- Memorial Sloan Kettering Cancer Center