1
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Rajendra E, Grande D, Mason B, Di Marcantonio D, Armstrong L, Hewitt G, Elinati E, Galbiati A, Boulton SJ, Heald RA, Smith GCM, Robinson HMR. Quantitative, titratable and high-throughput reporter assays to measure DNA double strand break repair activity in cells. Nucleic Acids Res 2024; 52:1736-1752. [PMID: 38109306 PMCID: PMC10899754 DOI: 10.1093/nar/gkad1196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/27/2023] [Accepted: 12/06/2023] [Indexed: 12/20/2023] Open
Abstract
Repair of DNA damage is essential for the maintenance of genome stability and cell viability. DNA double strand breaks (DSBs) constitute a toxic class of DNA lesion and multiple cellular pathways exist to mediate their repair. Robust and titratable assays of cellular DSB repair (DSBR) are important to functionally interrogate the integrity and efficiency of these mechanisms in disease models as well as in response to genetic or pharmacological perturbations. Several variants of DSBR reporters are available, however these are often limited by throughput or restricted to specific cellular models. Here, we describe the generation and validation of a suite of extrachromosomal reporter assays that can efficiently measure the major DSBR pathways of homologous recombination (HR), classical nonhomologous end joining (cNHEJ), microhomology-mediated end joining (MMEJ) and single strand annealing (SSA). We demonstrate that these assays can be adapted to a high-throughput screening format and that they are sensitive to pharmacological modulation, thus providing mechanistic and quantitative insights into compound potency, selectivity, and on-target specificity. We propose that these reporter assays can serve as tools to dissect the interplay of DSBR pathway networks in cells and will have broad implications for studies of DSBR mechanisms in basic research and drug discovery.
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Affiliation(s)
- Eeson Rajendra
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Diego Grande
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Bethany Mason
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | | | - Lucy Armstrong
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | | | - Elias Elinati
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | | | - Simon J Boulton
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
- The Francis Crick Institute, London NW1 1AT, UK
| | - Robert A Heald
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Graeme C M Smith
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
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2
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Schimmel J, Muñoz-Subirana N, Kool H, van Schendel R, van der Vlies S, Kamp JA, de Vrij FMS, Kushner SA, Smith GCM, Boulton SJ, Tijsterman M. Modulating mutational outcomes and improving precise gene editing at CRISPR-Cas9-induced breaks by chemical inhibition of end-joining pathways. Cell Rep 2023; 42:112019. [PMID: 36701230 DOI: 10.1016/j.celrep.2023.112019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/18/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Gene editing through repair of CRISPR-Cas9-induced chromosomal breaks offers a means to correct a wide range of genetic defects. Directing repair to produce desirable outcomes by modulating DNA repair pathways holds considerable promise to increase the efficiency of genome engineering. Here, we show that inhibition of non-homologous end joining (NHEJ) or polymerase theta-mediated end joining (TMEJ) can be exploited to alter the mutational outcomes of CRISPR-Cas9. We show robust inhibition of TMEJ activity at CRISPR-Cas9-induced double-strand breaks (DSBs) using ART558, a potent polymerase theta (Polϴ) inhibitor. Using targeted sequencing, we show that ART558 suppresses the formation of microhomology-driven deletions in favor of NHEJ-specific outcomes. Conversely, NHEJ deficiency triggers the formation of large kb-sized deletions, which we show are the products of mutagenic TMEJ. Finally, we show that combined chemical inhibition of TMEJ and NHEJ increases the efficiency of homology-driven repair (HDR)-mediated precise gene editing. Our work reports a robust strategy to improve the fidelity and safety of genome engineering.
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Affiliation(s)
- Joost Schimmel
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Núria Muñoz-Subirana
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Hanneke Kool
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Robin van Schendel
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Sven van der Vlies
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Juliette A Kamp
- Department of Psychiatry, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Femke M S de Vrij
- Department of Psychiatry, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Steven A Kushner
- Department of Psychiatry, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA
| | - Graeme C M Smith
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Simon J Boulton
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK; The Francis Crick Institute, London, UK
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands; Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands.
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3
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Stockley ML, Benedetti G, Blencowe P, Boulton SJ, Boyd SM, Calder M, Charles MD, Edwardes LV, Ekwuru T, Ferdinand A, Finch H, Galbiati A, Geo L, Grande D, Grinkevich V, Higgins GS, Holliday ND, Krajewski WW, MacDonald E, Majithiya JB, McCarron H, McWhirter CL, Patel V, Pedder C, Rajendra E, Ranzani M, Rigoreau LJM, Robinson HMR, Schaedler T, Sirina J, Smith GCM, Swarbrick ME, Turnbull AP, Willis S, Zemla A, Heald RA. Correction to "Discovery, Characterization, and Structure-Based Optimization of Small-Molecule In Vitro and In Vivo Probes for Human DNA Polymerase Theta". J Med Chem 2023; 66:3649-3649. [PMID: 36815444 DOI: 10.1021/acs.jmedchem.3c00204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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4
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Salguero C, Valladolid C, Robinson HMR, Smith GCM, Yap TA. Targeting ATR in Cancer Medicine. Cancer Treat Res 2023; 186:239-283. [PMID: 37978140 DOI: 10.1007/978-3-031-30065-3_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
As a key component of the DNA Damage Response, the Ataxia telangiectasia and Rad3-related (ATR) protein is a promising druggable target that is currently widely evaluated in phase I-II-III clinical trials as monotherapy and in combinations with other rational antitumor agents, including immunotherapy, DNA repair inhibitors, chemo- and radiotherapy. Ongoing clinical studies for this drug class must address the optimization of the therapeutic window to limit overlapping toxicities and refine the target population that will most likely benefit from ATR inhibition. With advances in the development of personalized treatment strategies for patients with advanced solid tumors, many ongoing ATR inhibitor trials have been recruiting patients based on their germline and somatic molecular alterations, rather than relying solely on specific tumor subtypes. Although a spectrum of molecular alterations have already been identified as potential predictive biomarkers of response that may sensitize to ATR inhibition, these biomarkers must be analytically validated and feasible to measure robustly to allow for successful integration into the clinic. While several ATR inhibitors in development are poised to address a clinically unmet need, no ATR inhibitor has yet received FDA-approval. This chapter details the underlying rationale for targeting ATR and summarizes the current preclinical and clinical landscape of ATR inhibitors currently in evaluation, as their regulatory approval potentially lies close in sight.
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Affiliation(s)
- Carolina Salguero
- Department of Investigational Cancer Therapeutics (Phase I Program), Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Christian Valladolid
- Department of Investigational Cancer Therapeutics (Phase I Program), Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Helen M R Robinson
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Graeme C M Smith
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Timothy A Yap
- Department of Investigational Cancer Therapeutics (Phase I Program), Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
- The Institute for Applied Cancer Science, and Institute for Personalized Cancer Therapy, The University of Texas MD Anderson Cancer Center, 1400 Holcombe Boulevard, TX, 77030, Houston, USA.
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5
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Belan O, Sebald M, Adamowicz M, Anand R, Vancevska A, Neves J, Grinkevich V, Hewitt G, Segura-Bayona S, Bellelli R, Robinson HMR, Higgins GS, Smith GCM, West SC, Rueda DS, Boulton SJ. POLQ seals post-replicative ssDNA gaps to maintain genome stability in BRCA-deficient cancer cells. Mol Cell 2022; 82:4664-4680.e9. [PMID: 36455556 DOI: 10.1016/j.molcel.2022.11.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/19/2022] [Accepted: 11/08/2022] [Indexed: 12/03/2022]
Abstract
POLQ is a key effector of DSB repair by microhomology-mediated end-joining (MMEJ) and is overexpressed in many cancers. POLQ inhibitors confer synthetic lethality in HR and Shieldin-deficient cancer cells, which has been proposed to reflect a critical dependence on the DSB repair pathway by MMEJ. Whether POLQ also operates independent of MMEJ remains unexplored. Here, we show that POLQ-deficient cells accumulate post-replicative ssDNA gaps upon BRCA1/2 loss or PARP inhibitor treatment. Biochemically, cooperation between POLQ helicase and polymerase activities promotes RPA displacement and ssDNA-gap fill-in, respectively. POLQ is also capable of microhomology-mediated gap skipping (MMGS), which generates deletions during gap repair that resemble the genomic scars prevalent in POLQ overexpressing cancers. Our findings implicate POLQ in mutagenic post-replicative gap sealing, which could drive genome evolution in cancer and whose loss places a critical dependency on HR for gap protection and repair and cellular viability.
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Affiliation(s)
- Ondrej Belan
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Marie Sebald
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Marek Adamowicz
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Roopesh Anand
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Aleksandra Vancevska
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Joana Neves
- Artios Pharma Ltd., B940 Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Vera Grinkevich
- Artios Pharma Ltd., B940 Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Graeme Hewitt
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Sandra Segura-Bayona
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Roberto Bellelli
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, UK
| | - Helen M R Robinson
- Artios Pharma Ltd., B940 Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Geoff S Higgins
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Graeme C M Smith
- Artios Pharma Ltd., B940 Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Stephen C West
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - David S Rueda
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London W12 0NN, UK; Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London W12 0NN, UK
| | - Simon J Boulton
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Artios Pharma Ltd., B940 Babraham Research Campus, Cambridge CB22 3FH, UK.
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6
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Stockley ML, Ferdinand A, Benedetti G, Blencowe P, Boyd SM, Calder M, Charles MD, Edwardes LV, Ekwuru T, Finch H, Galbiati A, Geo L, Grande D, Grinkevich V, Holliday ND, Krajewski WW, MacDonald E, Majithiya JB, McCarron H, McWhirter CL, Patel V, Pedder C, Rajendra E, Ranzani M, Rigoreau LJM, Robinson HMR, Schaedler T, Sirina J, Smith GCM, Swarbrick ME, Turnbull AP, Willis S, Heald RA. Discovery, Characterization, and Structure-Based Optimization of Small-Molecule In Vitro and In Vivo Probes for Human DNA Polymerase Theta. J Med Chem 2022; 65:13879-13891. [PMID: 36200480 DOI: 10.1021/acs.jmedchem.2c01142] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human DNA polymerase theta (Polθ), which is essential for microhomology-mediated DNA double strand break repair, has been proposed as an attractive target for the treatment of BRCA deficient and other DNA repair pathway defective cancers. As previously reported, we recently identified the first selective small molecule Polθ in vitro probe, 22 (ART558), which recapitulates the phenotype of Polθ loss, and in vivo probe, 43 (ART812), which is efficacious in a model of PARP inhibitor resistant TNBC in vivo. Here we describe the discovery, biochemical and biophysical characterization of these probes including small molecule ligand co-crystal structures with Polθ. The crystallographic data provides a basis for understanding the unique mechanism of inhibition of these compounds which is dependent on stabilization of a "closed" enzyme conformation. Additionally, the structural biology platform provided a basis for rational optimization based primarily on reduced ligand conformational flexibility.
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Affiliation(s)
- Martin L Stockley
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Amanda Ferdinand
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Giovanni Benedetti
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Peter Blencowe
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Susan M Boyd
- CompChem Solutions Ltd, St John's Innovation Centre, Cowley Rd, CambridgeCB4 0WS, U. K
| | - Mat Calder
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Mark D Charles
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Lucy V Edwardes
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Tennyson Ekwuru
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Harry Finch
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | | | - Lerin Geo
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Diego Grande
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Vera Grinkevich
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Nicholas D Holliday
- Excellerate Bioscience Ltd., BioCity, Pennyfoot Street, NottinghamNG1 1GF, U. K
| | - Wojciech W Krajewski
- Cancer Research Horizons Therapeutic Innovation, The Francis Crick Institute, 1 Midland Road, LondonNW1 1AT, U. K
| | - Ellen MacDonald
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Jayesh B Majithiya
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Hollie McCarron
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Claire L McWhirter
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Viral Patel
- Excellerate Bioscience Ltd., BioCity, Pennyfoot Street, NottinghamNG1 1GF, U. K
| | - Chris Pedder
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Eeson Rajendra
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Marco Ranzani
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Laurent J M Rigoreau
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Helen M R Robinson
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Theresia Schaedler
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Julija Sirina
- Excellerate Bioscience Ltd., BioCity, Pennyfoot Street, NottinghamNG1 1GF, U. K
| | - Graeme C M Smith
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Martin E Swarbrick
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Andrew P Turnbull
- Cancer Research Horizons Therapeutic Innovation, The Francis Crick Institute, 1 Midland Road, LondonNW1 1AT, U. K
| | - Simon Willis
- Cancer Research Horizons Therapeutic Innovation, The Francis Crick Institute, 1 Midland Road, LondonNW1 1AT, U. K
| | - Robert A Heald
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
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7
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Zatreanu DA, Robinson HMR, Alkhatib O, Boursier M, Finch H, Geo L, Grande D, Grinkevich V, Heald R, Langdon S, Majithiya J, McWhirter C, Martin NMB, Moore S, Neves J, Rajendra E, Ranzani M, Schaedler T, Stockley M, Wiggins K, Brough R, Sridhar S, Gulati A, Shao N, Badder LM, Novo D, Knight EG, Marlow R, Haider S, Callen E, Hewitt G, Schimmel J, Prevo R, Alli C, Ferdinand A, Bell C, Blencowe P, Calder M, Charles M, Curry J, Ekwuru T, Ewings K, Nussenzweig A, Tijsterman M, Tutt A, Boulton SJ, Higgins GS, Pettitt S, Smith GCM, Lord CJ. Abstract P056: Polθ inhibitors elicit BRCA-gene synthetic lethality and target PARP inhibitor resistance. Mol Cancer Ther 2021. [DOI: 10.1158/1535-7163.targ-21-p056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
To target DNA repair vulnerabilities in cancer, we discovered nanomolar potent, selective, low molecular weight, allosteric inhibitors of the polymerase function of DNA polymerase Theta (Polθ), including ART558. ART558 inhibits the major Polθ-mediated DNA repair process, Theta-Mediated End Joining (TMEJ), without targeting Non-Homologous End Joining. Moreover, we show that exposure to ART558 can elicit 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 are a cause of PARP inhibitor resistance, result in in vitro and in vivo sensitivity to Polθ polymerase inhibitors. Mechanistically, ART558 increases biomarkers of single-stranded DNA and synthetic lethality in 53BP1-defective cells. The inhibition of DNA nucleases that promote end-resection reversed these effects, suggesting that resection via Exo1 or Blm-Dna2 being a cause, at least in part, of the ART558 sensitivity phenotype. 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.
Citation Format: Diana A. Zatreanu, Helen M. R. Robinson, Omar Alkhatib, Marie Boursier, Harry Finch, Lerin Geo, Diego Grande, Vera Grinkevich, Robert Heald, Sophie Langdon, Jayesh Majithiya, Claire McWhirter, Niall M. B. Martin, Shaun Moore, Joana Neves, Eeson Rajendra, Marco Ranzani, Theresia Schaedler, Martin Stockley, Kimberley Wiggins, Rachel Brough, Sandhya Sridhar, Aditi Gulati, Nan Shao, Luned M Badder, Daniela Novo, Eleanor G. Knight, Rebecca Marlow, Syed Haider, Elsa Callen, Graeme Hewitt, Joost Schimmel, Remko Prevo, Christina Alli, Amanda Ferdinand, Cameron Bell, Peter Blencowe, Mathew Calder, Mark Charles, Jayne Curry, Tennyson Ekwuru, Katherine Ewings, Andre Nussenzweig, Marcel Tijsterman, Andrew Tutt, Simon J. Boulton, Geoff S. Higgins, Steve Pettitt, Graeme C. M. Smith, Christopher J. Lord. Polθ inhibitors elicit BRCA-gene synthetic lethality and target PARP inhibitor resistance [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P056.
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Affiliation(s)
| | | | | | | | | | - Lerin Geo
- 2Artios Pharma, Cambridge, United Kingdom,
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Rachel Brough
- 1Institute of Cancer Research, London, United Kingdom,
| | | | - Aditi Gulati
- 1Institute of Cancer Research, London, United Kingdom,
| | - Nan Shao
- 1Institute of Cancer Research, London, United Kingdom,
| | - Luned M Badder
- 3The Institute of Cancer Research, London, United Kingdom,
| | - Daniela Novo
- 1Institute of Cancer Research, London, United Kingdom,
| | | | | | - Syed Haider
- 1Institute of Cancer Research, London, United Kingdom,
| | | | - Graeme Hewitt
- 5The Francis Crick Institute, London, United Kingdom,
| | | | - Remko Prevo
- 7MRC-University of Oxford, Oxford, United Kingdom,
| | - Christina Alli
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Amanda Ferdinand
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Cameron Bell
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Peter Blencowe
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Mathew Calder
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Mark Charles
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Jayne Curry
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Tennyson Ekwuru
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | - Katherine Ewings
- 8CRUK-Therapeutic Discovery Laboratories, Cambridge, United Kingdom,
| | | | | | - Andrew Tutt
- 1Institute of Cancer Research, London, United Kingdom,
| | | | | | - Steve Pettitt
- 1Institute of Cancer Research, London, United Kingdom,
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8
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Paes Dias M, Tripathi V, van der Heijden I, Cong K, Manolika EM, Bhin J, Gogola E, Galanos P, Annunziato S, Lieftink C, Andújar-Sánchez M, Chakrabarty S, Smith GCM, van de Ven M, Beijersbergen RL, Bartkova J, Rottenberg S, Cantor S, Bartek J, Ray Chaudhuri A, Jonkers J. Loss of nuclear DNA ligase III reverts PARP inhibitor resistance in BRCA1/53BP1 double-deficient cells by exposing ssDNA gaps. Mol Cell 2021; 81:4692-4708.e9. [PMID: 34555355 DOI: 10.1016/j.molcel.2021.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 07/20/2021] [Accepted: 09/01/2021] [Indexed: 12/12/2022]
Abstract
Inhibitors of poly(ADP-ribose) (PAR) polymerase (PARPi) have entered the clinic for the treatment of homologous recombination (HR)-deficient cancers. Despite the success of this approach, preclinical and clinical research with PARPi has revealed multiple resistance mechanisms, highlighting the need for identification of novel functional biomarkers and combination treatment strategies. Functional genetic screens performed in cells and organoids that acquired resistance to PARPi by loss of 53BP1 identified loss of LIG3 as an enhancer of PARPi toxicity in BRCA1-deficient cells. Enhancement of PARPi toxicity by LIG3 depletion is dependent on BRCA1 deficiency but independent of the loss of 53BP1 pathway. Mechanistically, we show that LIG3 loss promotes formation of MRE11-mediated post-replicative ssDNA gaps in BRCA1-deficient and BRCA1/53BP1 double-deficient cells exposed to PARPi, leading to an accumulation of chromosomal abnormalities. LIG3 depletion also enhances efficacy of PARPi against BRCA1-deficient mammary tumors in mice, suggesting LIG3 as a potential therapeutic target.
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Affiliation(s)
- Mariana Paes Dias
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Vivek Tripathi
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015GD Rotterdam, the Netherlands
| | - Ingrid van der Heijden
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Ke Cong
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Eleni-Maria Manolika
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015GD Rotterdam, the Netherlands
| | - Jinhyuk Bhin
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Robotics and Screening Center, Division of Molecular Carcinogenesis, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Ewa Gogola
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Panagiotis Galanos
- Genome Integrity Unit, Danish Cancer Society Research Center, Copenhagen 2100, Denmark
| | - Stefano Annunziato
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Cor Lieftink
- Robotics and Screening Center, Division of Molecular Carcinogenesis, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands
| | - Miguel Andújar-Sánchez
- Pathology Department, Complejo Hospitalario Universitario Insular, Las Palmas, Gran Canaria, Spain
| | - Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Karnataka 576104, India
| | - Graeme C M Smith
- Artios Pharma, Glenn Berge Building, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Marieke van de Ven
- Mouse Clinic for Cancer and Aging, Preclinical Intervention Unit, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands
| | - Roderick L Beijersbergen
- Robotics and Screening Center, Division of Molecular Carcinogenesis, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands
| | - Jirina Bartkova
- Genome Integrity Unit, Danish Cancer Society Research Center, Copenhagen 2100, Denmark; Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, Science for Life Laboratory, Stockholm 171 77, Sweden
| | - Sven Rottenberg
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland
| | - Sharon Cantor
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jiri Bartek
- Genome Integrity Unit, Danish Cancer Society Research Center, Copenhagen 2100, Denmark; Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, Science for Life Laboratory, Stockholm 171 77, Sweden
| | - Arnab Ray Chaudhuri
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015GD Rotterdam, the Netherlands.
| | - Jos Jonkers
- Division of Molecular Pathology, the Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Oncode Institute, 1066CX Amsterdam, the Netherlands.
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9
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Zatreanu D, Robinson HMR, Alkhatib O, Boursier M, Finch H, Geo L, Grande D, Grinkevich V, Heald RA, Langdon S, Majithiya J, McWhirter C, Martin NMB, Moore S, Neves J, Rajendra E, Ranzani M, Schaedler T, Stockley M, Wiggins K, Brough R, Sridhar S, Gulati A, Shao N, Badder LM, Novo D, Knight EG, Marlow R, Haider S, Callen E, Hewitt G, Schimmel J, Prevo R, Alli C, Ferdinand A, Bell C, Blencowe P, Bot C, Calder M, Charles M, Curry J, Ekwuru T, Ewings K, Krajewski W, MacDonald E, McCarron H, Pang L, Pedder C, Rigoreau L, Swarbrick M, Wheatley E, Willis S, Wong AC, Nussenzweig A, Tijsterman M, Tutt A, Boulton SJ, Higgins GS, Pettitt SJ, Smith GCM, Lord CJ. Polθ inhibitors elicit BRCA-gene synthetic lethality and target PARP inhibitor resistance. Nat Commun 2021; 12:3636. [PMID: 34140467 PMCID: PMC8211653 DOI: 10.1038/s41467-021-23463-8] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/30/2021] [Indexed: 02/05/2023] Open
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.
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Affiliation(s)
- Diana Zatreanu
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Helen M R Robinson
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Omar Alkhatib
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Marie Boursier
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Harry Finch
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Lerin Geo
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Diego Grande
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Vera Grinkevich
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Robert A Heald
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Sophie Langdon
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Jayesh Majithiya
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Claire McWhirter
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Niall M B Martin
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Shaun Moore
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Joana Neves
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Eeson Rajendra
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Marco Ranzani
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Theresia Schaedler
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Martin Stockley
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Kimberley Wiggins
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Rachel Brough
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Sandhya Sridhar
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Aditi Gulati
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Nan Shao
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Luned M Badder
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Daniela Novo
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Eleanor G Knight
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Rebecca Marlow
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Syed Haider
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Elsa Callen
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | | | - Joost Schimmel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Remko Prevo
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Christina Alli
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Amanda Ferdinand
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Cameron Bell
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Peter Blencowe
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Chris Bot
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Mathew Calder
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Mark Charles
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Jayne Curry
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Tennyson Ekwuru
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Katherine Ewings
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Wojciech Krajewski
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ellen MacDonald
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Hollie McCarron
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Leon Pang
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Chris Pedder
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Laurent Rigoreau
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Martin Swarbrick
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ed Wheatley
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Simon Willis
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ai Ching Wong
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Andre Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Andrew Tutt
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Simon J Boulton
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
- The Francis Crick Institute, London, UK
| | - Geoff S Higgins
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Stephen J Pettitt
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK.
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK.
| | - Graeme C M Smith
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK.
| | - Christopher J Lord
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK.
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK.
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10
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Cano C, Saravanan K, Bailey C, Bardos J, Curtin NJ, Frigerio M, Golding BT, Hardcastle IR, Hummersone MG, Menear KA, Newell DR, Richardson CJ, Shea K, Smith GCM, Thommes P, Ting A, Griffin RJ. 1-substituted (Dibenzo[b,d]thiophen-4-yl)-2-morpholino-4H-chromen-4-ones endowed with dual DNA-PK/PI3-K inhibitory activity. J Med Chem 2013; 56:6386-401. [PMID: 23855836 DOI: 10.1021/jm400915j] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Analogues of (dibenzo[b,d]thiophen-4-yl)-2-morpholino-4H-chromen-4-one (NU7441), a potent inhibitor of DNA-dependent protein kinase (DNA-PK; IC50 = 42 ± 2 nM), have been synthesized in which water-solubilizing groups [NHCO(CH₂)nNR¹R², where n = 1 or 2 and the moiety R¹R²N was derived from a library of primary and secondary amines, e.g., morpholine] were placed at the 1-position. Several of the newly synthesized compounds exhibited high potency against DNA-PK and potentiated the cytotoxicity of ionizing radiation (IR) in vitro 10-fold or more (e.g., 2-(4-ethylpiperazin-1-yl)-N-(4-(2-morpholino-4-oxo-4H-chromen-8-yl)dibenzo[b,d]thio-phen-1-yl)acetamide, 39; DNA-PK IC₅₀ = 5.0 ± 1 nM, IR dose modification ratio = 13). Furthermore, 39 was shown to potentiate not only IR in vitro but also DNA-inducing cytotoxic anticancer agents, both in vitro and in vivo. Counter-screening against other members of the phosphatidylinositol 3-kinase (PI-3K) related kinase (PIKK) family unexpectedly revealed that some of the compounds were potent mixed DNA-PK and PI-3K inhibitors.
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Affiliation(s)
- Céline Cano
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom.
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11
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Pang LY, Scott M, Hayward RL, Mohammed H, Whitelaw CBA, Smith GCM, Hupp TR. p21(WAF1) is component of a positive feedback loop that maintains the p53 transcriptional program. Cell Cycle 2011; 10:932-50. [PMID: 21368573 DOI: 10.4161/cc.10.6.15012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The regulation of p53 activity through the MDM2 negative feedback loop is driven in part by an extrinsic ATM-pulse that maintains p53 oscillations in response to DNA damage. We report here that the p53 pathway has evolved an intrinsic positive feedback loop that is maintained by the p53-inducible gene product p21(WAF1). p21-null cancer cells have defects in p53 protein turnover, reductions in MDM2-mediated degradation of p53, and reduced DNA damage-induced ubiquitination of p53. TLR3-IRF1 or ATM-dependent signaling to p53 is defective in p21-null cells and complementation of the p21 gene in p21-null cancer cells restores the p53 transcriptional response. The mechanism of p53 inactivity in p21-null cells is linked to a p53 protein equilibrium shift from chromatin into cytosolic fractions and complementation of the p21 gene into p21-null cells restores the nuclear localization of p53. A loss of p53 transcriptional function in murine B-cells heterozygous or homozygous null for p21 highlights a p21-gene dosage effect that maintains the full p53 transcriptional response. ATM inhibition results in nuclear exclusion of p53 highlighting a positive genetic interaction between ATM and p21. P21 protein oscillates in undamaged proliferating cells, and reductions of p21 protein using siRNA eliminate the DNA damage-induced p53 pulse. The p53 transcription program has evolved a negative feedback loop maintained by MDM2 that is counteracted by a positive feedback loop maintained by ATM-p21 the balance of which controls the specific activity of p53 as a transcription factor.
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Affiliation(s)
- Lisa Y Pang
- CRUK Cell Signalling Unit, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland, UK
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12
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Cano C, Barbeau OR, Bailey C, Cockcroft XL, Curtin NJ, Duggan H, Frigerio M, Golding BT, Hardcastle IR, Hummersone MG, Knights C, Menear KA, Newell DR, Richardson CJ, Smith GCM, Spittle B, Griffin RJ. DNA-Dependent Protein Kinase (DNA-PK) Inhibitors. Synthesis and Biological Activity of Quinolin-4-one and Pyridopyrimidin-4-one Surrogates for the Chromen-4-one Chemotype. J Med Chem 2010; 53:8498-507. [DOI: 10.1021/jm100608j] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Céline Cano
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Olivier R. Barbeau
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Christine Bailey
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Xiao-Ling Cockcroft
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Nicola J. Curtin
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Heather Duggan
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Mark Frigerio
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Bernard T. Golding
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Ian R. Hardcastle
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Marc G. Hummersone
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Charlotte Knights
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Keith A. Menear
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - David R. Newell
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Caroline J. Richardson
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Graeme C. M. Smith
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Ben Spittle
- KuDOS Pharmaceuticals, Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, CB4 0PE, United Kingdom
| | - Roger J. Griffin
- Newcastle Cancer Centre, Northern Institute for Cancer Research, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
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13
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Chresta CM, Davies BR, Hickson I, Harding T, Cosulich S, Critchlow SE, Vincent JP, Ellston R, Jones D, Sini P, James D, Howard Z, Dudley P, Hughes G, Smith L, Maguire S, Hummersone M, Malagu K, Menear K, Jenkins R, Jacobsen M, Smith GCM, Guichard S, Pass M. AZD8055 is a potent, selective, and orally bioavailable ATP-competitive mammalian target of rapamycin kinase inhibitor with in vitro and in vivo antitumor activity. Cancer Res 2009; 70:288-98. [PMID: 20028854 DOI: 10.1158/0008-5472.can-09-1751] [Citation(s) in RCA: 608] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The mammalian target of rapamycin (mTOR) kinase forms two multiprotein complexes, mTORC1 and mTORC2, which regulate cell growth, cell survival, and autophagy. Allosteric inhibitors of mTORC1, such as rapamycin, have been extensively used to study tumor cell growth, proliferation, and autophagy but have shown only limited clinical utility. Here, we describe AZD8055, a novel ATP-competitive inhibitor of mTOR kinase activity, with an IC50 of 0.8 nmol/L. AZD8055 showed excellent selectivity (approximately 1,000-fold) against all class I phosphatidylinositol 3-kinase (PI3K) isoforms and other members of the PI3K-like kinase family. Furthermore, there was no significant activity against a panel of 260 kinases at concentrations up to 10 micromol/L. AZD8055 inhibits the phosphorylation of mTORC1 substrates p70S6K and 4E-BP1 as well as phosphorylation of the mTORC2 substrate AKT and downstream proteins. The rapamycin-resistant T37/46 phosphorylation sites on 4E-BP1 were fully inhibited by AZD8055, resulting in significant inhibition of cap-dependent translation. In vitro, AZD8055 potently inhibits proliferation and induces autophagy in H838 and A549 cells. In vivo, AZD8055 induces a dose-dependent pharmacodynamic effect on phosphorylated S6 and phosphorylated AKT at plasma concentrations leading to tumor growth inhibition. Notably, AZD8055 results in significant growth inhibition and/or regression in xenografts, representing a broad range of human tumor types. AZD8055 is currently in phase I clinical trials.
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14
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Mitchell J, Smith GCM, Curtin NJ. Poly(ADP-Ribose) polymerase-1 and DNA-dependent protein kinase have equivalent roles in double strand break repair following ionizing radiation. Int J Radiat Oncol Biol Phys 2009; 75:1520-7. [PMID: 19931734 DOI: 10.1016/j.ijrobp.2009.07.1722] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 06/29/2009] [Accepted: 07/14/2009] [Indexed: 12/30/2022]
Abstract
PURPOSE Radiation-induced DNA double strand breaks (DSBs) are predominantly repaired by nonhomologous end joining (NHEJ), involving DNA-dependent protein kinase (DNA-PK). Poly(ADP-ribose) polymerase-1 (PARP-1), well characterized for its role in single strand break repair, may also facilitate DSB repair. We investigated the activation of these enzymes by differing DNA ends and their interaction in the cellular response to ionizing radiation (IR). METHODS AND MATERIALS The effect of PARP and DNA-PK inhibitors (KU-0058684 and NU7441) on repair of IR-induced DSBs was investigated in DNA-PK and PARP-1 proficient and deficient cells by measuring gammaH2AX foci and neutral comets. Complementary in vitro enzyme kinetics assays demonstrated the affinities of DNA-PK and PARP-1 for DSBs with varying DNA termini. RESULTS DNA-PK and PARP-1 both promoted the fast phase of resolution of IR-induced DSBs in cells. Inactivation of both enzymes was not additive, suggesting that PARP-1 and DNA-PK cooperate within the same pathway to promote DSB repair. The affinities of the two enzymes for oligonucleotides with blunt, 3' GGG or 5' GGG overhanging termini were similar and overlapping (K(d)(app) = 2.6-6.4nM for DNA-PK; 1.7-4.5nM for PARP-1). DNA-PK showed a slightly greater affinity for overhanging DNA and was significantly more efficient when activated by a 5' GGG overhang. PARP-1 had a preference for blunt-ended DNA and required a separate factor for efficient stimulation by a 5' GGG overhang. CONCLUSION DNA-PK and PARP-1 are both required in a pathway facilitating the fast phase of DNA DSB repair.
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Affiliation(s)
- Jody Mitchell
- Northern Institute for Cancer Research, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
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15
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Hay T, Matthews JR, Pietzka L, Lau A, Cranston A, Nygren AOH, Douglas-Jones A, Smith GCM, Martin NMB, O'Connor M, Clarke AR. Poly(ADP-ribose) polymerase-1 inhibitor treatment regresses autochthonous Brca2/p53-mutant mammary tumors in vivo and delays tumor relapse in combination with carboplatin. Cancer Res 2009; 69:3850-5. [PMID: 19383921 DOI: 10.1158/0008-5472.can-08-2388] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Germ-line heterozygosity of the BRCA2 gene in women predisposes to breast and ovarian cancers. Successful therapies targeted specifically at these neoplasms have thus far remained elusive. Recent studies in mice have shown that inhibition of poly(ADP-ribose) polymerase-1 (PARP-1) targets cells lacking Brca2 and xenografts derived from BRCA2-deficient ES cells or Chinese hamster ovary cells. We set out to develop a more relevant preclinical model that will inform and accelerate translation into the clinic. As such, we conditionally deleted Brca2 and p53 within murine mammary epithelium and treated the resulting tumors in situ with a highly potent PARP-1 inhibitor (AZD2281) alone or in combination with carboplatin. Daily exposure to AZD2281 for 28 days caused significant regression or growth inhibition in 46 of 52 tumors. This response was shown to be specific to tumors lacking both Brca2and p53. AZD2281/carboplatin combination therapy for 28 days showed no advantage over carboplatin monotherapy. However, if PARP inhibitor treatment was continued, this significantly increased the time to tumor relapse and death in these mice. This preclinical study is the first to show in vivo hypersensitivity of spontaneously arising Brca2-deficient mammary tumors to PARP-1 inhibition monotherapy or combination therapy. As such, our data add substantial weight to the argument for the use of PARP inhibitors as therapeutic agents against human breast cancers in which BRCA2 is mutated. Moreover, the specificity that we have shown further suggests that PARP inhibitors will be generally effective against tumors caused by dysregulation of components of the homologous recombination pathway.
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Affiliation(s)
- Trevor Hay
- Department of Genetics, School of Biosciences, Cardiff University, Cardiff, United Kingdom
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16
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Evers B, Drost R, Schut E, de Bruin M, van der Burg E, Derksen PWB, Holstege H, Liu X, van Drunen E, Beverloo HB, Smith GCM, Martin NMB, Lau A, O'Connor MJ, Jonkers J. Selective inhibition of BRCA2-deficient mammary tumor cell growth by AZD2281 and cisplatin. Clin Cancer Res 2008; 14:3916-25. [PMID: 18559613 DOI: 10.1158/1078-0432.ccr-07-4953] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To assess efficacy of the novel, selective poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor AZD2281 against newly established BRCA2-deficient mouse mammary tumor cell lines and to determine potential synergy between AZD2281 and cisplatin. EXPERIMENTAL DESIGN We established and thoroughly characterized a panel of clonal cell lines from independent BRCA2-deficient mouse mammary tumors and BRCA2-proficient control tumors. Subsequently, we assessed sensitivity of these lines to conventional cytotoxic drugs and the novel PARP inhibitor AZD2281. Finally, in vitro combination studies were done to investigate interaction between AZD2281 and cisplatin. RESULTS Genetic, transcriptional, and functional analyses confirmed the successful isolation of BRCA2-deficient and BRCA2-proficient mouse mammary tumor cell lines. Treatment of these cell lines with 11 different anticancer drugs or with gamma-irradiation showed that AZD2281, a novel and specific PARP inhibitor, caused the strongest differential growth inhibition of BRCA2-deficient versus BRCA2-proficient mammary tumor cells. Finally, drug combination studies showed synergistic cytotoxicity of AZD2281 and cisplatin against BRCA2-deficient cells but not against BRCA2-proficient control cells. CONCLUSION We have successfully established the first set of BRCA2-deficient mammary tumor cell lines, which form an important addition to the existing preclinical models for BRCA-mutated breast cancer. The exquisite sensitivity of these cells to the PARP inhibitor AZD2281, alone or in combination with cisplatin, provides strong support for AZD2281 as a novel targeted therapeutic against BRCA-deficient cancers.
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Affiliation(s)
- Bastiaan Evers
- Division of Molecular Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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17
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Menear KA, Adcock C, Boulter R, Cockcroft XL, Copsey L, Cranston A, Dillon KJ, Drzewiecki J, Garman S, Gomez S, Javaid H, Kerrigan F, Knights C, Lau A, Loh VM, Matthews ITW, Moore S, O'Connor MJ, Smith GCM, Martin NMB. 4-[3-(4-cyclopropanecarbonylpiperazine-1-carbonyl)-4-fluorobenzyl]-2H-phthalazin-1-one: a novel bioavailable inhibitor of poly(ADP-ribose) polymerase-1. J Med Chem 2008; 51:6581-91. [PMID: 18800822 DOI: 10.1021/jm8001263] [Citation(s) in RCA: 440] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Poly(ADP-ribose) polymerase activation is an immediate cellular response to metabolic-, chemical-, or ionizing radiation-induced DNA damage and represents a new target for cancer therapy. In this article, we disclose a novel series of substituted 4-benzyl-2 H-phthalazin-1-ones that possess high inhibitory enzyme and cellular potency for both PARP-1 and PARP-2. Optimized compounds from the series also demonstrate good pharmacokinetic profiles, oral bioavailability, and activity in vivo in an SW620 colorectal cancer xenograft model. 4-[3-(4-Cyclopropanecarbonylpiperazine-1-carbonyl)-4-fluorobenzyl]-2 H-phthalazin-1-one (KU-0059436, AZD2281) 47 is a single digit nanomolar inhibitor of both PARP-1 and PARP-2 that shows standalone activity against BRCA1-deficient breast cancer cell lines. Compound 47 is currently undergoing clinical development for the treatment of BRCA1- and BRCA2-defective cancers.
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Affiliation(s)
- Keith A Menear
- KuDOS Pharmaceuticals Ltd., 410 Cambridge Science Park, Milton Road, Cambridge, U.K.
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18
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Menear KA, Adcock C, Alonso FC, Blackburn K, Copsey L, Drzewiecki J, Fundo A, Le Gall A, Gomez S, Javaid H, Lence CF, Martin NMB, Mydlowski C, Smith GCM. Novel alkoxybenzamide inhibitors of poly(ADP-ribose) polymerase. Bioorg Med Chem Lett 2008; 18:3942-5. [PMID: 18579376 DOI: 10.1016/j.bmcl.2008.06.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 06/06/2008] [Accepted: 06/06/2008] [Indexed: 02/04/2023]
Abstract
We have previously described poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors based on a substituted benzyl-phthalazinone scaffold. As an alternative chemical template, a novel series of alkoxybenzamides were developed with restricted conformation through intramolecular hydrogen bond formation; the compounds exhibit low nM enzyme and cellular activity as PARP-1 inhibitors.
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Affiliation(s)
- Keith A Menear
- KuDOS Pharmaceuticals Ltd, 410 Cambridge Science Park, Milton Road, Cambridge CB4 0PE, UK.
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19
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Hollick JJ, Rigoreau LJM, Cano-Soumillac C, Cockcroft X, Curtin NJ, Frigerio M, Golding BT, Guiard S, Hardcastle IR, Hickson I, Hummersone MG, Menear KA, Martin NMB, Matthews I, Newell DR, Ord R, Richardson CJ, Smith GCM, Griffin RJ. Pyranone, Thiopyranone, and Pyridone Inhibitors of Phosphatidylinositol 3-Kinase Related Kinases. Structure−Activity Relationships for DNA-Dependent Protein Kinase Inhibition, and Identification of the First Potent and Selective Inhibitor of the Ataxia Telangiectasia Mutated Kinase. J Med Chem 2007; 50:1958-72. [PMID: 17371003 DOI: 10.1021/jm061121y] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Structure-activity relationships have been investigated for inhibition of DNA-dependent protein kinase (DNA-PK) and ATM kinase by a series of pyran-2-ones, pyran-4-ones, thiopyran-4-ones, and pyridin-4-ones. A wide range of IC50 values were observed for pyranones and thiopyranones substituted at the 6-position, with the 3- and 5-positions proving intolerant to substitution. Related pyran-2-ones, pyran-4-ones, and thiopyran-4-ones showed similar IC50 values against DNA-PK, whereas the pyridin-4-one system proved, in general, ineffective at inhibiting DNA-PK. Extended libraries exploring the 6-position of 2-morpholino-pyran-4-ones and 2-morpholino-thiopyrano-4-ones identified the first highly potent and selective ATM inhibitor 2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one (151C; ATM; IC50=13 nM) and revealed constrained SARs for ATM inhibition compared with DNA-PK. One of the most potent DNA-PK inhibitors identified, 2-(4-methoxyphenyl)-6-(morpholin-4-yl)pyran-4-one (16; DNA-PK; IC50=220 nM) effectively sensitized HeLa cells to the topoisomerase II inhibitor etoposide in vitro.
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Affiliation(s)
- Jonathan J Hollick
- Northern Institute for Cancer Research, School of Natural Sciences-Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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20
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Barbeau OR, Cano-Soumillac C, Griffin RJ, Hardcastle IR, Smith GCM, Richardson C, Clegg W, Harrington RW, Golding BT. Quinolinone and pyridopyrimidinone inhibitors of DNA-dependent protein kinase. Org Biomol Chem 2007; 5:2670-7. [DOI: 10.1039/b705095j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Tutt ANJ, Lord CJ, McCabe N, Farmer H, Turner N, Martin NM, Jackson SP, Smith GCM, Ashworth A. Exploiting the DNA repair defect in BRCA mutant cells in the design of new therapeutic strategies for cancer. Cold Spring Harb Symp Quant Biol 2006; 70:139-48. [PMID: 16869747 DOI: 10.1101/sqb.2005.70.012] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Individuals harboring germ-line mutations in the BRCA1 or BRCA2 genes are at highly elevated risk of a variety of cancers. Ten years of research has revealed roles for BRCA1 and BRCA2 in a wide variety of cellular processes. However, it seems likely that the function of these proteins in DNA repair is critically important in maintaining genome stability. Despite this increasing knowledge of the defects present in BRCA-deficient cells, BRCA mutation carriers developing cancer are still treated similarly to sporadic cases. Here we describe our efforts, based on understanding the DNA repair defects in BRCAdeficient cells, to define the optimal existing treatment for cancers arising in BRCA mutation carriers and, additionally, the development of novel therapeutic approaches. Finally, we discuss how therapies developed to treat BRCA mutant tumors might be applied to some sporadic cancers sharing similar specific defects in DNA repair.
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Affiliation(s)
- A N J Tutt
- The Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, London, UK
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22
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McCabe N, Turner NC, Lord CJ, Kluzek K, Bialkowska A, Swift S, Giavara S, O'Connor MJ, Tutt AN, Zdzienicka MZ, Smith GCM, Ashworth A. Deficiency in the Repair of DNA Damage by Homologous Recombination and Sensitivity to Poly(ADP-Ribose) Polymerase Inhibition. Cancer Res 2006; 66:8109-15. [PMID: 16912188 DOI: 10.1158/0008-5472.can-06-0140] [Citation(s) in RCA: 956] [Impact Index Per Article: 53.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Deficiency in either of the breast cancer susceptibility proteins BRCA1 or BRCA2 induces profound cellular sensitivity to the inhibition of poly(ADP-ribose) polymerase (PARP) activity. We hypothesized that the critical role of BRCA1 and BRCA2 in the repair of double-strand breaks by homologous recombination (HR) was the underlying reason for this sensitivity. Here, we examine the effects of deficiency of several proteins involved in HR on sensitivity to PARP inhibition. We show that deficiency of RAD51, RAD54, DSS1, RPA1, NBS1, ATR, ATM, CHK1, CHK2, FANCD2, FANCA, or FANCC induces such sensitivity. This suggests that BRCA-deficient cells are, at least in part, sensitive to PARP inhibition because of HR deficiency. These results indicate that PARP inhibition might be a useful therapeutic strategy not only for the treatment of BRCA mutation-associated tumors but also for the treatment of a wider range of tumors bearing a variety of deficiencies in the HR pathway or displaying properties of 'BRCAness.'
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Affiliation(s)
- Nuala McCabe
- Cancer Research UK Gene Function and Regulation Group and The Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, London, United Kingdom
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23
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Zhao Y, Thomas HD, Batey MA, Cowell IG, Richardson CJ, Griffin RJ, Calvert AH, Newell DR, Smith GCM, Curtin NJ. Preclinical evaluation of a potent novel DNA-dependent protein kinase inhibitor NU7441. Cancer Res 2006; 66:5354-62. [PMID: 16707462 DOI: 10.1158/0008-5472.can-05-4275] [Citation(s) in RCA: 306] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
DNA double-strand breaks (DSB) are the most cytotoxic lesions induced by ionizing radiation and topoisomerase II poisons, such as etoposide and doxorubicin. A major pathway for the repair of DSB is nonhomologous end joining, which requires DNA-dependent protein kinase (DNA-PK) activity. We investigated the therapeutic use of a potent, specific DNA-PK inhibitor (NU7441) in models of human cancer. We measured chemosensitization by NU7441 of topoisomerase II poisons and radiosensitization in cells deficient and proficient in DNA-PK(CS) (V3 and V3-YAC) and p53 wild type (LoVo) and p53 mutant (SW620) human colon cancer cell lines by clonogenic survival assay. Effects of NU7441 on DSB repair and cell cycle arrest were measured by gammaH2AX foci and flow cytometry. Tissue distribution of NU7441 and potentiation of etoposide activity were determined in mice bearing SW620 tumors. NU7441 increased the cytotoxicity of ionizing radiation and etoposide in SW620, LoVo, and V3-YAC cells but not in V3 cells, confirming that potentiation was due to DNA-PK inhibition. NU7441 substantially retarded the repair of ionizing radiation-induced and etoposide-induced DSB. NU7441 appreciably increased G(2)-M accumulation induced by ionizing radiation, etoposide, and doxorubicin in both SW620 and LoVo cells. In mice bearing SW620 xenografts, NU7441 concentrations in the tumor necessary for chemopotentiation in vitro were maintained for at least 4 hours at nontoxic doses. NU7441 increased etoposide-induced tumor growth delay 2-fold without exacerbating etoposide toxicity to unacceptable levels. In conclusion, NU7441 shows sufficient proof of principle through in vitro and in vivo chemosensitization and radiosensitization to justify further development of DNA-PK inhibitors for clinical use.
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Affiliation(s)
- Yan Zhao
- Northern Institute for Cancer Research, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom
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24
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Hardcastle IR, Cockcroft X, Curtin NJ, El-Murr MD, Leahy JJJ, Stockley M, Golding BT, Rigoreau L, Richardson C, Smith GCM, Griffin RJ. Discovery of potent chromen-4-one inhibitors of the DNA-dependent protein kinase (DNA-PK) using a small-molecule library approach. J Med Chem 2006; 48:7829-46. [PMID: 16302822 DOI: 10.1021/jm050444b] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Structure-activity relationships for inhibition of DNA-dependent protein kinase (DNA-PK) have been defined for substituted chromen-4-ones. For the 2-amino-substituted benzo[h]chromen-4-ones, a morpholine substituent at this position was essential for activity. Small libraries of 6- and 7-alkoxy-substituted chromen-4-ones showed that a number of 7-alkoxy-substituted chromenones displayed improved activity. Focused libraries incorporating 6-, 7-, and 8-aryl and heteroaryl substituents were prepared. In these cases, 6- and 7-substitution was disfavored, whereas 8-substitution was largely tolerated. Surprisingly, two compounds, 2-N-morpholino-8-dibenzofuranyl-chromen-4-one (NU7427, 32{38}) and the 2-N-morpholino-8-dibenzothiophenyl-chromen-4-one (NU7441, 32{26}) were excellent inhibitors (IC50 vs DNA-PK = 40 and 13 nM, respectively). The ring-saturated analogue 2-N-morpholino-8-(6',7',8',9'-tetrahydrodibenzothiophene)chromen-4-one, 36, retained potent activity (IC50 vs DNA-PK = 23 nM). The dibenzothiophene 32{38} sensitized HeLa cells to ionizing radiation in vitro, with dose modification factors of 2.5 at 10% survival being observed at 0.5 microM. The cytotoxicity of the topoisomerase II inhibitor etoposide was also potentiated.
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Affiliation(s)
- Ian R Hardcastle
- Northern Institute for Cancer Research, School of Natural Sciences--Chemistry, Bedson Building, Newcastle upon Tyne NE1 7RU, UK.
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25
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Cockcroft XL, Dillon KJ, Dixon L, Drzewiecki J, Kerrigan F, Loh VM, Martin NMB, Menear KA, Smith GCM. Phthalazinones 2: Optimisation and synthesis of novel potent inhibitors of poly(ADP-ribose)polymerase. Bioorg Med Chem Lett 2006; 16:1040-4. [PMID: 16290932 DOI: 10.1016/j.bmcl.2005.10.081] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 10/19/2005] [Accepted: 10/22/2005] [Indexed: 11/15/2022]
Abstract
We have previously described the discovery of poly(ADP-ribose)polymerase-1 (PARP-1) inhibitors based on a phthalazinone scaffold. Subsequent optimisation of inhibitory activity, metabolic stability and pharmacokinetic parameters has led to a novel series of meta-substituted 4-benzyl-2H-phthalazin-1-one PARP-1 inhibitors which retain low nM cellular activity and show good stability in vivo and efficacy in cell based models.
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Affiliation(s)
- Xiao-Ling Cockcroft
- KuDOS Pharmaceuticals Ltd 327 Cambridge Science Park, Milton Road, Cambridge, CB4 0WG, UK.
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26
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Nutley BP, Smith NF, Hayes A, Kelland LR, Brunton L, Golding BT, Smith GCM, Martin NMB, Workman P, Raynaud FI. Preclinical pharmacokinetics and metabolism of a novel prototype DNA-PK inhibitor NU7026. Br J Cancer 2005; 93:1011-8. [PMID: 16249792 PMCID: PMC2361671 DOI: 10.1038/sj.bjc.6602823] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In this study we investigated the in vitro time dependence of radiosensitisation, pharmacokinetics and metabolism of NU7026, a novel inhibitor of the DNA repair enzyme DNA-dependent protein kinase (DNA-PK). At a dose of 10 μM, which is nontoxic to cells per se, a minimum NU7026 exposure of 4 h in combination with 3 Gy radiation is required for a significant radiosensitisation effect in CH1 human ovarian cancer cells. Following intravenous administration to mice at 5 mg kg−1, NU7026 underwent rapid plasma clearance (0.108 l h−1) and this was largely attributed to extensive metabolism. Bioavailability following interperitoneal (i.p.) and p.o. administration at 20 mg kg−1 was 20 and 15%, respectively. Investigation of NU7026 metabolism profiles in plasma and urine indicated that the compound undergoes multiple hydroxylations. A glucuronide conjugate of a bis-hydroxylated metabolite represented the major excretion product in urine. Identification of the major oxidation site as C-2 of the morpholine ring was confirmed by the fact that the plasma clearance of NU7107 (an analogue of NU7026 methylated at C-2 and C-6 of the morpholine ring) was four-fold slower than that of NU7026. The pharmacokinetic simulations performed predict that NU7026 will have to be administered four times per day at 100 mg kg−1 i.p. in order to obtain the drug exposure required for radiosensitisation.
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Affiliation(s)
- B P Nutley
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
| | - N F Smith
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
| | - A Hayes
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
| | - L R Kelland
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
| | - L Brunton
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
| | - B T Golding
- Northern Institute of Cancer Research, School of Natural Sciences – Chemistry, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - G C M Smith
- KuDOS Pharmaceuticals Ltd, 327 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, UK
| | - N M B Martin
- KuDOS Pharmaceuticals Ltd, 327 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, UK
| | - P Workman
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
| | - F I Raynaud
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton SM2 5NG, UK. E-mail:
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27
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Jazayeri A, Falck J, Lukas C, Bartek J, Smith GCM, Lukas J, Jackson SP. ATM- and cell cycle-dependent regulation of ATR in response to DNA double-strand breaks. Nat Cell Biol 2005; 8:37-45. [PMID: 16327781 DOI: 10.1038/ncb1337] [Citation(s) in RCA: 794] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 11/04/2005] [Indexed: 11/09/2022]
Abstract
It is generally thought that the DNA-damage checkpoint kinases, ataxia-telangiectasia mutated (ATM) and ATM- and Rad3-related (ATR), work independently of one another. Here, we show that ATM and the nuclease activity of meiotic recombination 11 (Mre11) are required for the processing of DNA double-strand breaks (DSBs) to generate the replication protein A (RPA)-coated ssDNA that is needed for ATR recruitment and the subsequent phosphorylation and activation of Chk1. Moreover, we show that efficient ATM-dependent ATR activation in response to DSBs is restricted to the S and G2 cell cycle phases and requires CDK kinase activity. Thus, in response to DSBs, ATR activation is regulated by ATM in a cell-cycle dependent manner.
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Affiliation(s)
- Ali Jazayeri
- The Wellcome Trust and Cancer Research UK Gurdon Institute, and Department of Zoology, Cambridge University, Tennis Court Road, Cambridge, CB2 1QN, UK
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28
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Hay T, Jenkins H, Sansom OJ, Martin NMB, Smith GCM, Clarke AR. Efficient Deletion of Normal Brca2-Deficient Intestinal Epithelium by Poly(ADP-Ribose) Polymerase Inhibition Models Potential Prophylactic Therapy. Cancer Res 2005; 65:10145-8. [PMID: 16287996 DOI: 10.1158/0008-5472.can-05-1186] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The genes encoding the BRCA1 and BRCA2 tumor suppressors are the most commonly mutated in human familial breast cancers. Both have separate roles in the maintenance of genomic stability through involvement in homologous recombination, an error-free process enabling cells to repair DNA double-strand breaks. We have previously shown that cre-mediated conditional deletion of Brca2 within the mouse small intestine sensitizes the tissue to DNA damage. Eventually, the tissue repopulates via stem cells in which recombination at the floxed Brca2 allele has not taken place. In this study, we have treated Brca2-deficient small intestine with a potent small-molecule inhibitor of poly(ADP-ribose) polymerase 1 (PARP1), an enzyme predominantly involved in the recognition of DNA single-strand breaks. Brca2 deficiency rendered otherwise normal cells exquisitely sensitive to PARP inhibition, resulting in very high levels of apoptosis as early as 6 hours after treatment, with evidence for repopulation of the tissue at 12 hours. Furthermore, the intestines of animals treated with serial injections of the inhibitor repopulated very rapidly in comparison with those from untreated mice. Our results represent the first in vivo demonstration that inhibition of PARP1 activity confers exquisite sensitivity to death in physiologically normal Brca2-deficient cells, suggesting that such a regimen may be extremely potent prophylactically in women heterozygous for the BRCA2 gene, as well as against established tumors lacking functional BRCA2.
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Affiliation(s)
- Trevor Hay
- School of Bioscience, Cardiff University, Cardiff, United Kingdom
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29
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McCabe N, Lord CJ, Tutt ANJ, Martin NMB, Smith GCM, Ashworth A. BRCA2-deficient CAPAN-1 cells are extremely sensitive to the inhibition of Poly (ADP-Ribose) polymerase: an issue of potency. Cancer Biol Ther 2005; 4:934-6. [PMID: 16251802 DOI: 10.4161/cbt.4.9.2141] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We have previously demonstrated that deficiency of either the BRCA1 or BRCA2 breast cancer susceptibility proteins confers substantial cellular sensitivity to the inhibition of Poly(ADP-Ribose) polymerase (PARP). PARP is a key enzyme in the repair of single strand DNA damage via the Base Excision Repair pathway. We suggested that PARP inhibition produces persistent single-strand DNA breaks or gaps which degenerate into stalled replication forks and double-strand breaks, which may be repaired by homologous recombination, a process partially dependent on BRCA1 and BRCA2. It has recently been suggested that our results might be limited to certain BRCA2 mutations as the CAPAN-1 cell line, which carries a naturally occurring 6174delT mutation in one BRCA2 allele accompanied by loss of the wild-type allele, is apparently insensitive to two PARP inhibitors 3-aminobenzamide (IC50 33 microM) and NU1025 (IC50 400 nM). Here we show that CAPAN-1 cells are in fact very sensitive to the potent PARP inhibitors KU0058684 (IC50 3.2 nM) and KU0058948 (IC50 3.4 nM). In contrast, our results reveal much less sensitivity to a chemically related but much less active compound KU0051529 (IC50 730 nM) and to NU1025. These results confirm that treatment with potent PARP inhibitors remains an exciting potential therapy for cancers involving BRCA1 or BRCA2 deficiency.
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Affiliation(s)
- Nuala McCabe
- The Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, London, UK
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30
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Loh VM, Cockcroft XL, Dillon KJ, Dixon L, Drzewiecki J, Eversley PJ, Gomez S, Hoare J, Kerrigan F, Matthews ITW, Menear KA, Martin NMB, Newton RF, Paul J, Smith GCM, Vile J, Whittle AJ. Phthalazinones. Part 1: The design and synthesis of a novel series of potent inhibitors of poly(ADP-ribose)polymerase. Bioorg Med Chem Lett 2005; 15:2235-8. [PMID: 15837300 DOI: 10.1016/j.bmcl.2005.03.026] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Revised: 03/04/2005] [Accepted: 03/07/2005] [Indexed: 11/29/2022]
Abstract
Screening of the Maybridge compound collection identified 4-arylphthalazinones as micromolar inhibitors of PARP-1 catalytic activity. Subsequent optimisation of both inhibitory activity and metabolic stability led to a novel series of meta-substituted 4-benzyl-2H-phthalazin-1-ones with low nanomolar, cellular activity as PARP-1 inhibitors and promising metabolic stability in vitro.
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Affiliation(s)
- Vincent M Loh
- KuDOS Horsham Ltd, 26 Foundry Lane, Horsham, West Sussex RH13 5PX, UK.
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31
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Farmer H, McCabe N, Lord CJ, Tutt ANJ, Johnson DA, Richardson TB, Santarosa M, Dillon KJ, Hickson I, Knights C, Martin NMB, Jackson SP, Smith GCM, Ashworth A. Targeting the DNA repair defect in BRCA mutant cells as a therapeutic strategy. Nature 2005; 434:917-21. [PMID: 15829967 DOI: 10.1038/nature03445] [Citation(s) in RCA: 4535] [Impact Index Per Article: 238.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Accepted: 02/11/2005] [Indexed: 02/06/2023]
Abstract
BRCA1 and BRCA2 are important for DNA double-strand break repair by homologous recombination, and mutations in these genes predispose to breast and other cancers. Poly(ADP-ribose) polymerase (PARP) is an enzyme involved in base excision repair, a key pathway in the repair of DNA single-strand breaks. We show here that BRCA1 or BRCA2 dysfunction unexpectedly and profoundly sensitizes cells to the inhibition of PARP enzymatic activity, resulting in chromosomal instability, cell cycle arrest and subsequent apoptosis. This seems to be because the inhibition of PARP leads to the persistence of DNA lesions normally repaired by homologous recombination. These results illustrate how different pathways cooperate to repair damage, and suggest that the targeted inhibition of particular DNA repair pathways may allow the design of specific and less toxic therapies for cancer.
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Affiliation(s)
- Hannah Farmer
- Cancer Research UK Gene Function and Regulation Group, London, UK
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32
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Leahy JJJ, Golding BT, Griffin RJ, Hardcastle IR, Richardson C, Rigoreau L, Smith GCM. Identification of a highly potent and selective DNA-dependent protein kinase (DNA-PK) inhibitor (NU7441) by screening of chromenone libraries. Bioorg Med Chem Lett 2005; 14:6083-7. [PMID: 15546735 DOI: 10.1016/j.bmcl.2004.09.060] [Citation(s) in RCA: 293] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 09/17/2004] [Accepted: 09/21/2004] [Indexed: 11/29/2022]
Abstract
A solution-phase multiple-parallel synthesis approach was employed for the preparation of 6-, 7- and 8-aryl-substituted chromenone libraries, which were screened as inhibitors of the DNA repair enzyme DNA-dependent protein kinase (DNA-PK). These studies resulted in the identification of 8-dibenzothiophen-4-yl-2-morpholin-4-yl-chromen-4-one (NU7441) as a highly potent and selective DNA-PK inhibitor (IC50=14 nM), exhibiting ATP-competitive inhibition kinetics.
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Affiliation(s)
- Justin J J Leahy
- Northern Institute for Cancer Research, School of Natural Sciences-Chemistry, Bedson Building, University of Newcastle, Newcastle Upon Tyne NE1 7RU, UK
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Lau A, Swinbank KM, Ahmed PS, Taylor DL, Jackson SP, Smith GCM, O'Connor MJ. Suppression of HIV-1 infection by a small molecule inhibitor of the ATM kinase. Nat Cell Biol 2005; 7:493-500. [PMID: 15834407 DOI: 10.1038/ncb1250] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Accepted: 03/29/2005] [Indexed: 01/14/2023]
Abstract
Chemotherapy that is used to treat human immunodeficiency virus type-1 (HIV-1) infection focuses primarily on targeting virally encoded proteins. However, the combination of a short retroviral life cycle and high mutation rate leads to the selection of drug-resistant HIV-1 variants. One way to address this problem is to inhibit non-essential host cell proteins that are required for viral replication. Here we show that the activity of HIV-1 integrase stimulates an ataxia-telangiectasia-mutated (ATM)-dependent DNA damage response, and that a deficiency of this ATM kinase sensitizes cells to retrovirus-induced cell death. Consistent with these observations, we demonstrate that a novel and specific small molecule inhibitor of ATM kinase activity, KU-55933, is capable of suppressing the replication of both wild-type and drug-resistant HIV-1.
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Affiliation(s)
- Alan Lau
- KuDOS Pharmaceuticals Limited, 327 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, UK
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Griffin RJ, Fontana G, Golding BT, Guiard S, Hardcastle IR, Leahy JJJ, Martin N, Richardson C, Rigoreau L, Stockley M, Smith GCM. Selective benzopyranone and pyrimido[2,1-a]isoquinolin-4-one inhibitors of DNA-dependent protein kinase: synthesis, structure-activity studies, and radiosensitization of a human tumor cell line in vitro. J Med Chem 2005; 48:569-85. [PMID: 15658870 DOI: 10.1021/jm049526a] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A diverse range of chromen-2-one, chromen-4-one and pyrimidoisoquinolin-4-one derivatives was synthesized and evaluated for inhibitory activity against the DNA repair enzyme DNA-dependent protein kinase (DNA-PK), with a view to elucidating structure-activity relationships for potency and kinase selectivity. DNA-PK inhibitory activity varied widely over the series of compounds evaluated (IC(50) values ranged from 0.19 to >10 microM), with excellent activity being observed for the 7,8-benzochromen-4-one and pyrimido[2,1-a]isoquinolin-4-one templates. By contrast, inhibitors based on the benzochromen-2-one (coumarin) or 2-aryl-7,8-benzochromen-4-one (flavone) scaffolds were less potent. Crucially, these studies revealed a very constrained structure-activity relationship at the 2-position of the benzopyranone and pyrimido[2,1-a]isoquinolin-4-one pharmacophore, with only a 2-morpholino or 2-(2'-methylmorpholino) group being tolerated at this position. More detailed biological studies conducted with the most potent inhibitor NU7163 (48; IC(50) = 0.19 microM) demonstrated ATP-competitive DNA-PK inhibition, with a K(i) value of 24 nM, and 48 exhibited selectivity for DNA-PK compared with the related enzymes ATM, ATR, mTOR, and PI 3-K (p110alpha). Compound 48 sensitized the HeLa human tumor cell line to the cytotoxic effects of ionizing radiation in vitro, a dose modification factor of 2.3 at 10% survival being observed with an inhibitor concentration of 5 microM. This study identified these structural classes as novel DNA-PK inhibitors and delineated initial structure-activity relationships against DNA-PK.
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Affiliation(s)
- Roger J Griffin
- Northern Institute for Cancer Research, School of Natural Sciences-Chemistry, Bedson Building, The University, Newcastle upon Tyne NE1 7RU, UK
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Hickson I, Zhao Y, Richardson CJ, Green SJ, Martin NMB, Orr AI, Reaper PM, Jackson SP, Curtin NJ, Smith GCM. Identification and characterization of a novel and specific inhibitor of the ataxia-telangiectasia mutated kinase ATM. Cancer Res 2005; 64:9152-9. [PMID: 15604286 DOI: 10.1158/0008-5472.can-04-2727] [Citation(s) in RCA: 942] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The serine/threonine protein kinase ATM signals to cell cycle and DNA repair components by phosphorylating downstream targets such as p53, CHK2, NBS1, and BRCA1. Mutation of ATM occurs in the human autosomal recessive disorder ataxia-telangiectasia, which is characterized by hypersensitivity to ionizing radiation and a failure of cells to arrest the cell cycle after the induction of DNA double-strand breaks. It has thus been proposed that ATM inhibition would cause cellular radio- and chemosensitization. Through screening a small molecule compound library developed for the phosphatidylinositol 3'-kinase-like kinase family, we identified an ATP-competitive inhibitor, 2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one (KU-55933), that inhibits ATM with an IC(50) of 13 nmol/L and a Ki of 2.2 nmol/L. KU-55933 shows specificity with respect to inhibition of other phosphatidylinositol 3'-kinase-like kinases. Cellular inhibition of ATM by KU-55933 was demonstrated by the ablation of ionizing radiation-dependent phosphorylation of a range of ATM targets, including p53, gammaH2AX, NBS1, and SMC1. KU-55933 did not show inhibition of UV light DNA damage induced cellular phosphorylation events. Exposure of cells to KU-55933 resulted in a significant sensitization to the cytotoxic effects of ionizing radiation and to the DNA double-strand break-inducing chemotherapeutic agents, etoposide, doxorubicin, and camptothecin. Inhibition of ATM by KU-55933 also caused a loss of ionizing radiation-induced cell cycle arrest. By contrast, KU-55933 did not potentiate the cytotoxic effects of ionizing radiation on ataxia-telangiectasia cells, nor did it affect their cell cycle profile after DNA damage. We conclude that KU-55933 is a novel, specific, and potent inhibitor of the ATM kinase.
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Affiliation(s)
- Ian Hickson
- KuDOS Pharmaceuticals Ltd., Cambridge Science Park, Milton Road, Cambridge, UK
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Riballo E, Kühne M, Rief N, Doherty A, Smith GCM, Recio MJ, Reis C, Dahm K, Fricke A, Krempler A, Parker AR, Jackson SP, Gennery A, Jeggo PA, Löbrich M. A Pathway of Double-Strand Break Rejoining Dependent upon ATM, Artemis, and Proteins Locating to γ-H2AX Foci. Mol Cell 2004; 16:715-24. [PMID: 15574327 DOI: 10.1016/j.molcel.2004.10.029] [Citation(s) in RCA: 652] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Revised: 09/14/2004] [Accepted: 10/27/2004] [Indexed: 02/06/2023]
Abstract
The hereditary disorder ataxia telangiectasia (A-T) is associated with striking cellular radiosensitivity that cannot be attributed to the characterized cell cycle checkpoint defects. By epistasis analysis, we show that ataxia telangiectasia mutated protein (ATM) and Artemis, the protein defective in patients with RS-SCID, function in a common double-strand break (DSB) repair pathway that also requires H2AX, 53BP1, Nbs1, Mre11, and DNA-PK. We show that radiation-induced Artemis hyperphosphorylation is ATM dependent. The DSB repair process requires Artemis nuclease activity and rejoins approximately 10% of radiation-induced DSBs. Our findings are consistent with a model in which ATM is required for Artemis-dependent processing of double-stranded ends with damaged termini. We demonstrate that Artemis is a downstream component of the ATM signaling pathway required uniquely for the DSB repair function but dispensable for ATM-dependent cell cycle checkpoint arrest. The significant radiosensitivity of Artemis-deficient cells demonstrates the importance of this component of DSB repair to survival.
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Affiliation(s)
- Enriqueta Riballo
- Genome Damage and Stability Centre, University of Sussex, East Sussex, BN1 9RQ, United Kingdom
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Veuger SJ, Curtin NJ, Smith GCM, Durkacz BW. Effects of novel inhibitors of poly(ADP-ribose) polymerase-1 and the DNA-dependent protein kinase on enzyme activities and DNA repair. Oncogene 2004; 23:7322-9. [PMID: 15286704 DOI: 10.1038/sj.onc.1207984] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DNA-dependent protein kinase (DNA-PK) and poly (ADP-ribose) polymerase-1 (PARP-1) participate in nonhomologous end joining and base excision repair, respectively, and are key determinants of radio- and chemo-resistance. Both PARP-1 and DNA-PK have been identified as therapeutic targets for anticancer drug development. Here we investigate the effects of specific inhibitors on enzyme activities and DNA double-strand break (DSB) repair. The enzyme activities were investigated using purified enzymes and in permeabilized cells. Inhibition, or loss of activity, was compared using potent inhibitors of DNA-PK (NU7026) and PARP-1 (AG14361), and cell lines proficient or deficient for DNA-PK or PARP-1. Inactive DNA-PK suppressed the activity of PARP-1 and vice versa. This was not the consequence of simple substrate competition, since DNA ends were provided in excess. The inhibitory effect of DNA-PK on PARP activity was confirmed in permeabilized cells. Both inhibitors prevented ionizing radiation-induced DSB repair, but only AG14361 prevented single-strand break repair. An increase in DSB levels caused by inhibition of PARP-1 was shown to be caused by a decrease in DSB repair, and not by the formation of additional DSBs. These data point to combined inhibition of PARP-1 and DNA-PK as a powerful strategy for tumor radiosensitization.
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Affiliation(s)
- Stephany J Veuger
- Northern Institute for Cancer Research, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
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Veuger SJ, Curtin NJ, Richardson CJ, Smith GCM, Durkacz BW. Radiosensitization and DNA repair inhibition by the combined use of novel inhibitors of DNA-dependent protein kinase and poly(ADP-ribose) polymerase-1. Cancer Res 2003; 63:6008-15. [PMID: 14522929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The DNA repair enzymes, DNA-dependent protein kinase (DNA-PK) and poly(ADP-ribose) polymerase-1 (PARP-1), are key determinants of radio- and chemo-resistance. We have developed and evaluated novel specific inhibitors of DNA-PK (NU7026) and PARP-1 (AG14361) for use in anticancer therapy. PARP-1- and DNA-PK-deficient cell lines were 4-fold more sensitive to ionizing radiation (IR) alone, and showed reduced potentially lethal damage recovery (PLDR) in G(0) cells, compared with their proficient counterparts. NU7026 (10 micro M) potentiated IR cytotoxicity [potentiation factor at 90% cell kill (PF(90)) = 1.51 +/- 0.04] in exponentially growing DNA-PK proficient but not deficient cells. Similarly, AG14361 (0.4 micro M) potentiated IR in PARP-1(+/+) (PF(90) = 1.37 +/- 0.03) but not PARP-1(-/-) cells. When NU7026 and AG14361 were used in combination, their potentiating effects were additive (e.g., PF(90) = 2.81 +/- 0.19 in PARP-1(+/+) cells). Both inhibitors alone reduced PLDR approximately 3-fold in the proficient cell lines. Furthermore, the inhibitor combination completely abolished PLDR. IR-induced DNA double strand break (DNA DSB) repair was inhibited by both NU7026 and AG14361, and use of the inhibitor combination prevented 90% of DNA DSB rejoining, even 24-h postirradiation. Thus, there was a correlation between the ability of the inhibitors to prevent IR-induced DNA DSB repair and their ability to potentiate cytotoxicity. Thus, individually, or in combination, the DNA-PK and PARP-1 inhibitors act as potent radiosensitizers and show potential as tools for anticancer therapeutic intervention.
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Affiliation(s)
- Stephany J Veuger
- Northern Institute for Cancer Research, Medical School, University of Newcastle, Newcastle upon Tyne, United Kingdom
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Hollick JJ, Golding BT, Hardcastle IR, Martin N, Richardson C, Rigoreau LJM, Smith GCM, Griffin RJ. 2,6-disubstituted pyran-4-one and thiopyran-4-one inhibitors of DNA-Dependent protein kinase (DNA-PK). Bioorg Med Chem Lett 2003; 13:3083-6. [PMID: 12941339 DOI: 10.1016/s0960-894x(03)00652-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
6-aryl-2-morpholin-4-yl-4H-pyran-4-ones and 6-aryl-2-morpholin-4-yl-4H-thiopyran-4-ones were synthesised and evaluated as potential inhibitors of the DNA repair enzyme DNA-dependent protein kinase (DNA-PK). Several compounds in each series exhibited superior activity to the chromenone LY294002, and were of comparable potency to the benzochromenone NU7026 (IC(50)=0.23 microM). Importantly, members of both structural classes were found to be selective inhibitors of DNA-PK over related phosphatidylinositol 3-kinase-related kinase (PIKK) family members. A multiple-parallel synthesis approach, employing Suzuki cross-coupling methodology, was utilised to prepare libraries of thiopyran-4-ones with a range of aromatic groups at the 3'- and 4'-positions on the thiopyran-4-one 6-aryl ring. Screening of the libraries resulted in the identification of 6-aryl-2-morpholin-4-yl-4H-thiopyran-4-ones bearing naphthyl or benzo[b]thienyl substituents at the 4'-position, as potent DNA-PK inhibitors with IC(50) values in the 0.2-0.4 microM range.
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Affiliation(s)
- Jonathan J Hollick
- Northern Institute for Cancer Research, School of Natural Sciences-Chemistry, Bedson Building, University of Newcastle, Newcastle Upon Tyne NE1 7RU, UK
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Abstract
A novel FlashPlate scintillation proximity assay has been developed for the high-throughput screening (HTS) of large compound libraries to identify inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1), an important enzyme involved in DNA repair. The assay was originally developed for the 96-well FlashPlate but is easily transferred to a 384-well format. Moreover, the authors demonstrate that the assay is sufficiently sensitive to determine accurate IC(50) values and adaptable for kinetic evaluation of lead molecules. The mechanism of action of the assay requires the binding of PARP-1 to a double-stranded DNA oligonucleotide leading to the active enzyme. Using NAD(+) and (3)H-NAD(+) as substrate, activated PARP-1 synthesizes labeled poly(ADP-ribose) chains. Once the reaction is stopped, ADP-ribose polymers are brought into proximity with the pretreated FlashPlate walls, resulting in signal amplification. This signal is then detected by a TopCount scintillation plate reader. The developed assay is a robust and reproducible method of screening for PARP-1 inhibitors that is low maintenance and cost-effective and can easily be automated.
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