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Updated: Aug 10, 2026

Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1
Published on: February 17, 2011
Novel p53 mutants selected in BRCA-associated tumours which dissociate transformation suppression from other
P D Smith1, S Crossland, G Parker
1Institute of Cancer Research, Haddow Laboratories, Sutton, Surrey, UK.
Abstract:
Inheritance of germ-line mutant alleles of BRCA1 and BRCA2 confers a markedly increased risk of breast cancer and we have previously reported a higher incidence of p53 mutations in these tumours than in grade matched sporadic tumours. We have now characterized these p53 mutants. The results of these studies identify a novel class of p53 mutants previously undescribed in human cancer yet with multiple occurrences in BRCA-associated tumours which retain a profile of p53-dependent activities in terms of transactivation, growth suppression and apoptosis induction which is close or equal to wild-type. However, these mutants fail to suppress transformation and exhibit gain of function transforming activity in rat embryo fibroblasts. These mutants therefore fall into a novel category of p53 mutants which dissociate transformation suppression from other wild-type functions. The rarity of these mutants in human cancer and their multiple occurrence in BRCA-associated breast tumours suggests that these novel p53 mutants are selected during malignant progression in the unique genetic background of BRCA1- and BRCA2-associated tumours.
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