Tumorigenesis in mice carrying a truncating Brca1 mutation

Abstract

We generated mouse mutants carrying in the Brca1 locus a modification (Brca1 ^tr) that eliminates the C-terminal half of the protein product and obtained results indicating that, depending on genetic background, the missing BRCT and/or other domains are dispensable for survival, but essential for tumor suppression. Most of the apparently hypomorphic Brca1 ^tr/tr mutants developed various tumors. Lymphomas were detected at all ages, whereas sarcomas and carcinomas, including breast cancer, appeared after a long latency. The mammary tumors showed striking variability in histopathological patterns suggesting stochastic engagement of tumorigenic pathways in their progression, to which theBrca1 ^tr/tr mutation was apparently a late participant.