Interferon restores replication fork stability and cell viability in BRCA-defective cells via ISG15
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ABSTRACT: DNA replication and repair defects or genotoxic treatments trigger interferon (IFN)-mediated inflammatory responses. However, whether and how IFN signaling in turn impacts the DNA replication process has remained elusive. Here we show that basal levels of the IFN-stimulated gene 15, ISG15, and its conjugation (ISGylation) are essential to protect nascent DNA from degradation. Moreover, IFN treatment restores replication fork stability in BRCA1/2-deficient cells, which strictly depends on topoisomerase-1, and rescues lethality of BRCA2-deficient mouse embryonic stem cells. Although IFN activates hundreds of genes, these effects are specifically mediated by ISG15 and ISGylation, as their inactivation suppresses the impact of IFN on DNA replication. ISG15 depletion significantly reduces cell proliferation rates in human BRCA1-mutated triple-negative, whereas its upregulation results in increased resistance to the chemotherapeutic drug cisplatin in mouse BRCA2-deficient breast cancer cells, respectively. Accordingly, cells carrying BRCA1/2 defects consistently show increased ISG15 levels, which we propose as a novel, in-built mechanism of drug resistance linked to BRCAness.
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Homo Sapiens (human)
SUBMITTER: Lorenza Penengo
LAB HEAD: Lorenza Penengo
PROVIDER: PXD045154 | Pride | 2023-10-09
REPOSITORIES: Pride
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