Luminal breast epithelial cells of BRCA1 or BRCA2 mutation carriers and noncarriers harbor common breast cancer copy number alterations.

ABSTRACT: The prevalence and nature of somatic copy number alterations (CNAs) in breast epithelium and their role in tumor initiation and evolution remain poorly understood. Using single-cell DNA sequencing (49,238 cells) of epithelium from BRCA1 and BRCA2 carriers or wild-type individuals, we identified recurrent CNAs (for example, 1q-gain and 7q, 10q, 16q and 22q-loss) that are present in a rare population of cells across almost all samples (n = 28). In BRCA1/BRCA2 carriers, these occur before loss of heterozygosity (LOH) of wild-type alleles. These CNAs, common in malignant tumors, are enriched in luminal cells but absent in basal myoepithelial cells. Allele-specific analysis of prevalent CNAs reveals that they arose by independent mutational events, consistent with convergent evolution. BRCA1/BR

SUBMITTER: Williams MJ 

PROVIDER: S-EPMC11631757 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature