Haploinsufficiency in Telomere Maintenance.

Our previous studies showed an association between monoallelic germline mutations and dysfunctional telomeres in epithelial mammary cell lines and increased risk of breast cancer diagnosis for women with germline mutation and short telomeres in blood cells. In the current study, we analyzed telomere dysfunction in lymphoid cell lines from five mutation carriers and three Fanconi Anemia D1 patients by fluorescence in situ hybridization (FISH). Metaphase chromosomes were harvested from ten lymphoid cell lines of different genotype origin and analyzed for telomere loss (TL), multitelomeric signals (MTS), interstitial telomere signals (ITS) and extra chromosomal telomere signals (ECTS).

Dysfunctional telomeres in human BRCA2 mutated breast tumors and cell lines.

In the present study the possible involvement of telomeres in chromosomal instability of breast tumors and cell lines from BRCA2 mutation carriers was examined. Breast tumors from BRCA2 mutation carriers showed significantly higher frequency of chromosome end-to-end fusions (CEFs) than tumors from non-carriers despite normal telomere DNA content. Frequent CEFs were also found in four different BRCA2 heterozygous breast epithelial cell lines, occasionally with telomere signal at the fusion point, indicating telomere capping defects.

Genomic and phenotypic analysis of BRCA2 mutated breast cancers reveals co-occurring changes linked to progression.

Background: Inherited mutations in the BRCA2 gene greatly increase the risk of developing breast cancer. Consistent with an important role for BRCA2 in error-free DNA repair, complex genomic changes are frequently observed in tumors derived from BRCA2 mutation carriers. Here, we explore the impact of DNA copy-number changes in BRCA2 tumors with respect to phenotype and clinical staging of the disease.

Germline Brca2 heterozygosity promotes Kras(G12D) -driven carcinogenesis in a murine model of familial pancreatic cancer.

Inherited heterozygous BRCA2 mutations predispose carriers to tissue-specific cancers, but somatic deletion of the wild-type allele is considered essential for carcinogenesis. We find in a murine model of familial pancreatic cancer that germline heterozygosity for a pathogenic Brca2 truncation suffices to promote pancreatic ductal adenocarcinomas (PDACs) driven by Kras(G12D), irrespective of Trp53 status. Unexpectedly, tumor cells retain a functional Brca2 allele.