EXO1-mediated DNA repair by single-strand annealing is essential for BRCA1-deficient cells.

Autor: van de Kooij B, Schreuder A, Pavani RS, Garzero V, Van Hoeck A, San Martin Alonso M, Koerse D, Wendel TJ, Callen E, Boom J, Mei H, Cuppen E, Nussenzweig A, van Attikum H, Noordermeer SM
Jazyk: angličtina
Zdroj: BioRxiv : the preprint server for biology [bioRxiv] 2023 Feb 24. Date of Electronic Publication: 2023 Feb 24.
DOI: 10.1101/2023.02.24.529205
Abstrakt: Deficiency for the repair of DNA double-strand breaks (DSBs) via homologous recombination (HR) leads to chromosomal instability and diseases such as cancer. Yet, defective HR also results in vulnerabilities that can be exploited for targeted therapy. Here, we identify such a vulnerability and show that BRCA1-deficient cells are dependent on the long-range end-resection factor EXO1 for survival. EXO1 loss results in DNA replication-induced lesions decorated by poly(ADP-ribose)-chains. In cells that lack both BRCA1 and EXO1, this is accompanied by unresolved DSBs due to impaired single-strand annealing (SSA), a DSB repair process that requires the activity of both proteins. In contrast, BRCA2-deficient cells have increased SSA, also in the absence of EXO1, and hence are not dependent on EXO1 for survival. In agreement with our mechanistic data, BRCA1-mutated tumours have elevated EXO1 expression and contain more genomic signatures of SSA compared to BRCA1-proficient tumours. Collectively, our data indicate that EXO1 is a promising novel target for treatment of BRCA1-deficient tumours.
Databáze: MEDLINE