Common cancer-associated imbalances in the DNA damage response confer sensitivity to single agent ATR inhibition

ATR is an attractive target in cancer therapy because it signals replication stress and DNA lesions for repair and to S/G2 checkpoints. Cancer-specific defects in the DNA damage response (DDR) may render cancer cells vulnerable to ATR inhibition alone. We determined the cytotoxicity of the ATR inhibitor VE-821 in isogenically matched cells with DDR imbalance. Cell cycle arrest, DNA damage accumulation and repair were determined following VE-821 exposure.Defects in homologous recombination repair (HRR: ATM, BRCA2 and XRCC3) and base excision repair (BER: XRCC1) conferred sensitivity to VE-821. Surprisingly, the loss of different components of the trimeric non-homologous end-joining (NHEJ) protein DNA-PK had opposing effects. Loss of the DNA-binding component, Ku80, caused hypersensitivity to VE-821, but loss of its partner catalytic subunit, DNA-PKcs, did not. Unexpectedly, VE-821 was particularly cytotoxic to human and hamster cells expressing high levels of DNA-PKcs. High DNA-PKcs was associated with replicative stress and activation of the DDR. VE-821 suppressed HRR, determined by RAD51 focus formation, to a greater extent in cells with high DNA-PKcs.Defects in HRR and BER and high DNA-PKcs expression, that are common in cancer, confer sensitivity to ATR inhibitor monotherapy and may be developed as predictive biomarkers for personalised medicine.

Medienart:

E-Artikel

Erscheinungsjahr:

2015

Erschienen:

2015

Enthalten in:

Zur Gesamtaufnahme - volume:6

Enthalten in:

Oncotarget - 6(2015), 32 vom: 20. Okt., Seite 32396-409

Sprache:

Englisch

Beteiligte Personen:

Middleton, Fiona K [VerfasserIn]
Patterson, Miranda J [VerfasserIn]
Elstob, Claire J [VerfasserIn]
Fordham, Sarah [VerfasserIn]
Herriott, Ashleigh [VerfasserIn]
Wade, Mark A [VerfasserIn]
McCormick, Aiste [VerfasserIn]
Edmondson, Richard [VerfasserIn]
May, Felicity E B [VerfasserIn]
Allan, James M [VerfasserIn]
Pollard, John R [VerfasserIn]
Curtin, Nicola J [VerfasserIn]

Links:

Volltext

Themen:

3-amino-6-(4-(methylsulfonyl)phenyl)-N-phenylpyrazine-2-carboxamide
ATR
ATR protein, human
Antineoplastic Agents
Ataxia Telangiectasia Mutated Proteins
DNA Repair Enzymes
DNA damage response
DNA-Activated Protein Kinase
DNA-PKcs
EC 2.7.11.1
EC 6.5.1.-
Journal Article
MYC protein, human
Nuclear Proteins
P53
PRKDC protein, human
Protein Kinase Inhibitors
Proto-Oncogene Proteins c-myc
Pyrazines
Research Support, Non-U.S. Gov't
Sulfones
Synthetic lethality

Anmerkungen:

Date Completed 12.08.2016

Date Revised 13.11.2018

published: Print

Citation Status MEDLINE

doi:

10.18632/oncotarget.6136

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM253867967