Journal article icon

Journal article

Polθ inhibitors elicit BRCA-gene synthetic lethality and target PARP inhibitor resistance

Abstract:
To identify approaches to target DNA repair vulnerabilities in cancer, we discovered nanomolar potent, selective, low molecular weight (MW), allosteric inhibitors of the polymerase function of DNA polymerase Polθ, including ART558. ART558 inhibits the major Polθ-mediated DNA repair process, Theta-Mediated End Joining, without targeting Non-Homologous End Joining. In addition, ART558 elicits DNA damage and synthetic lethality in BRCA1- or BRCA2-mutant tumour cells and enhances the effects of a PARP inhibitor. Genetic perturbation screening revealed that defects in the 53BP1/Shieldin complex, which cause PARP inhibitor resistance, result in in vitro and in vivo sensitivity to small molecule Polθ polymerase inhibitors. Mechanistically, ART558 increases biomarkers of single-stranded DNA and synthetic lethality in 53BP1-defective cells whilst the inhibition of DNA nucleases that promote end-resection reversed these effects, implicating these in the synthetic lethal mechanism-of-action. Taken together, these observations describe a drug class that elicits BRCA-gene synthetic lethality and PARP inhibitor synergy, as well as targeting a biomarker-defined mechanism of PARPi-resistance.
Publication status:
Published
Peer review status:
Peer reviewed

Actions


Access Document


Files:
Publisher copy:
10.1038/s41467-021-23463-8

Authors


More by this author
Institution:
University of Oxford
Division:
MSD
Sub department:
CRUK/MRC Ox Inst for Radiation Oncology
Role:
Author
ORCID:
0000-0001-5196-0552


Publisher:
Springer Nature
Journal:
Nature Communications More from this journal
Volume:
12
Issue:
1
Article number:
3636
Publication date:
2021-06-17
Acceptance date:
2021-04-30
DOI:
ISSN:
2041-1723


Language:
English
Keywords:
Pubs id:
1178302
Local pid:
pubs:1178302
Deposit date:
2021-05-24

Terms of use



Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP