Innovative Approaches for Determining the Role of BRCA2 and BRCA1 in DNA Recombinational Repair: Examination of Genetic Instability and Possible Therapeutic Uses
Abstract
The purpose of this research is to determine a role for BRCAl and BRCA2 in the recombinational repair of DNA double-strand breaks. The inability of a cell to precisely repair chromosomal breaks may lead to genetic instability and consequently promote carcinogenesis. Products of the BRCAl and BRCA2 genes have been shown to interact with Rad5 1, a component of homologous repair pathways known to precisely repair breaks. In this annual report we describe a homologous gene targeting defect in Brcal-deficient ES cells. We also measured gene conversion within a substrate containing GFP gene repeats, one of which is mutated by the recognition site of the rare-cutting 1-Sce I endonuclease. Following expression of 1-Sce I, repair of an induced break can be monitored by measuring green fluorescence within the cell. We have found that repair of a chromosomal break by gene conversion is diminished in the Brcal-deficient ES cells. Additionally, we have analyzed gene targeting in ES cells that contain a truncated Brca2 gene. These results directly demonstrate that cells deficient in Brcal have reduced homologous repair of an induced chromosomal double-strand break. This defect may contribute to the propensity to develop early- onset breast and ovarian cancers by increasing genetic instability.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1999
- Accession Number
- ADB262568
Entities
People
- Maria Jasin
Organizations
- Memorial Sloan Kettering Cancer Center