Insights from three decades of BRCA1/2 modeling in mice.

Since the discovery of the BRCA1 and BRCA2 (hereafter referred to as BRCA1/2) hereditary breast and ovarian cancer genes three decades ago, genetically engineered and patient-derived mouse models have been instrumental in advancing our understanding of BRCA1/2 biology, particularly their roles in normal development, tumor suppression and therapy response. Brca1/2-mutant mouse models and derivative cell lines have facilitated in vivo dissection of BRCA1/2 functions and identification of the cellular origin and (epi)genetic drivers of BRCA1/2-associated cancer. Genetically engineered and patient-derived mouse tumor models have also been instrumental in developing new (combination) therapies for patients with BRCA1/2-mutated cancers and to study mechanisms of therapy resistance. In this Perspective, we highlight the crucial insights into the complex biology of BRCA1/2 these models have afforded and emphasize those aspects that remain to be elucidated. We also propose next-generation mouse models to further advance our understanding of BRCA1/2 and improve the quality of life of mutation carriers.