Auranofin improves chemotherapeutic response of breast tumor by targeting TOPBP1-nucleated protein complexes
Ontology highlight
ABSTRACT: Genome instability is most commonly caused by replication stress, which also renders cancer cells extremely vulnerable once their response to replication stress is impeded. Topoisomerase II binding protein 1 (TOPBP1), an allosteric activator of ataxia telangiectasia and Rad3 related (ATR) kinase, coordinates ATR in replication stress response and has emerged as a potential therapeutic target for tumors. Here, we identify auranofin, the FDA-approved drug for rheumatoid arthritis, as a lead compound capable of binding to the BRCT 7-8 domains and blocking TOPBP1 interaction with PHF8 and FANCJ. The liquid-liquid phase separation (LLPS) of TOPBP1 was also disrupted by auranofin. Through targeting these TOPBP1-nucleated molecular machineries, auranofin leads to an accumulation of replication defects by impairing ATR activation and attenuating RPA loading on perturbed replication forks, and it shows significant anti-breast tumor activity in combination with PARP inhibitor (PARPi). This study provides mechanistic insights into how auranofin challenges replication integrity and expands the application of this FDA-approved drug in breast tumor intervention.
ORGANISM(S): Homo Sapiens
SUBMITTER:
Lei Shi
PROVIDER: PXD066377 | iProX | Mon Jul 21 00:00:00 BST 2025
REPOSITORIES: iProX
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