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Updated: Oct 9, 2026

Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1
Published on: February 17, 2011
Chromosomal instability in BRCA1- or BRCA2-defective human cancer cells detected by spontaneous micronucleus assay
1Department of Radiobiology, Radiation Effects Research Foundation, Hijiyama Park 5-2, Minami-ku, 732-0815, Hiroshima, Japan. ban@rerf.or.jp
Abstract:
The BRCA1 and BRCA2 gene products are believed to play an important part in the onset and/or development of many sporadic mammary cancers. Recently, it has been reported that these two proteins contribute to a centrosome function which is believed to help maintain the integrity of the chromosome segregation process. This may mean a reduced level of the BRCA1 or BRCA2 protein in mammary cells will occasionally lead to nondisjunctional chromosomal loss or gain. We now report that spontaneous micronuclei arising from chromosome(s) which fail to be incorporated into the relevant daughter nuclei during mitosis tend to occur more frequently in BRCA1- or BRCA2-defective human cancer cells than in BRCA-positive cancer cells. Some cases of mammary carcinogenesis may therefore stem from the loss of integrity of chromosome segregation in cells which have a reduced capacity to express either BRCA1 or BRCA2.
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