RNF8 ubiquitylation of XRN2 facilitates R-loop resolution and restrains genomic instability in BRCA1 mutant cells

Rehna Krishnan, Mariah Lapierre, Brandon Gautreau, Kevin C.J. Nixon, Samah El Ghamrasni, Parasvi S. Patel, Jun Hao, V. Talya Yerlici, Kiran Kumar Naidu Guturi, Jonathan St-Germain, Francesca Mateo, Amine Saad, Arash Algouneh, Rebecca Earnshaw, Duan Shili, Alma Seitova, Joshua Miller, Negin Khosraviani, Adam Penn, Brandon HoOtto Sanchez, M. Prakash Hande, Jean Yves Masson, Grant W. Brown, Moulay Alaoui-Jamali, John J. Reynolds, Cheryl Arrowsmith, Brian Raught, Miguel A. Pujana, Karim Mekhail, Grant S. Stewart, Anne Hakem*, Razqallah Hakem*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Breast cancer linked with BRCA1/2 mutations commonly recur and resist current therapies, including PARP inhibitors. Given the lack of effective targeted therapies for BRCA1-mutant cancers, we sought to identify novel targets to selectively kill these cancers. Here, we report that loss of RNF8 significantly protects Brca1-mutant mice against mammary tumorigenesis. RNF8 deficiency in human BRCA1-mutant breast cancer cells was found to promote R-loop accumulation and replication fork instability, leading to increased DNA damage, senescence, and synthetic lethality. Mechanistically, RNF8 interacts with XRN2, which is crucial for transcription termination and R-loop resolution. We report that RNF8 ubiquitylates XRN2 to facilitate its recruitment to R-loop-prone genomic loci and that RNF8 deficiency in BRCA1-mutant breast cancer cells decreases XRN2 occupancy at R-loop-prone sites, thereby promoting R-loop accumulation, transcription-replication collisions, excessive genomic instability, and cancer cell death. Collectively, our work identifies a synthetic lethal interaction between RNF8 and BRCA1, which is mediated by a pathological accumulation of R-loops.

Original languageEnglish
Pages (from-to)10484-10505
Number of pages22
JournalNucleic Acids Research
Issue number19
Early online date11 Sept 2023
Publication statusPublished - 27 Oct 2023

Bibliographical note

Copyright © The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License
(https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact [email protected]

Data Access Statement

The data underlying this article are available in GEO at https://www.ncbi.nlm.nih.gov/geo/, and can be accessed with accession number GSE202723.


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