1
|
Rodriguez-Berriguete G, Ranzani M, Prevo R, Puliyadi R, Machado N, Bolland HR, Millar V, Ebner D, Boursier M, Cerutti A, Cicconi A, Galbiati A, Grande D, Grinkevich V, Majithiya JB, Piscitello D, Rajendra E, Stockley ML, Boulton SJ, Hammond EM, Heald RA, Smith GC, Robinson HM, Higgins GS. Small-Molecule Polθ Inhibitors Provide Safe and Effective Tumor Radiosensitization in Preclinical Models. Clin Cancer Res 2023; 29:1631-1642. [PMID: 36689546 PMCID: PMC10102842 DOI: 10.1158/1078-0432.ccr-22-2977] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 09/27/2022] [Revised: 12/19/2022] [Accepted: 01/19/2023] [Indexed: 01/24/2023]
Abstract
PURPOSE DNA polymerase theta (Polθ, encoded by the POLQ gene) is a DNA repair enzyme critical for microhomology mediated end joining (MMEJ). Polθ has limited expression in normal tissues but is frequently overexpressed in cancer cells and, therefore, represents an ideal target for tumor-specific radiosensitization. In this study we evaluate whether targeting Polθ with novel small-molecule inhibitors is a feasible strategy to improve the efficacy of radiotherapy. EXPERIMENTAL DESIGN We characterized the response to Polθ inhibition in combination with ionizing radiation in different cancer cell models in vitro and in vivo. RESULTS Here, we show that ART558 and ART899, two novel and specific allosteric inhibitors of the Polθ DNA polymerase domain, potently radiosensitize tumor cells, particularly when combined with fractionated radiation. Importantly, noncancerous cells were not radiosensitized by Polθ inhibition. Mechanistically, we show that the radiosensitization caused by Polθ inhibition is most effective in replicating cells and is due to impaired DNA damage repair. We also show that radiosensitization is still effective under hypoxia, suggesting that these inhibitors may help overcome hypoxia-induced radioresistance. In addition, we describe for the first time ART899 and characterize it as a potent and specific Polθ inhibitor with improved metabolic stability. In vivo, the combination of Polθ inhibition using ART899 with fractionated radiation is well tolerated and results in a significant reduction in tumor growth compared with radiation alone. CONCLUSIONS These results pave the way for future clinical trials of Polθ inhibitors in combination with radiotherapy.
Collapse
Affiliation(s)
| | - Marco Ranzani
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | - Remko Prevo
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Rathi Puliyadi
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Nicole Machado
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Hannah R. Bolland
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Val Millar
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Daniel Ebner
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Marie Boursier
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | - Aurora Cerutti
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - Diego Grande
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | - Vera Grinkevich
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - Eeson Rajendra
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | - Simon J. Boulton
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
- The Francis Crick Institute, London, United Kingdom
| | - Ester M. Hammond
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Robert A. Heald
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - Geoff S. Higgins
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
2
|
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]
|
3
|
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.
Collapse
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
| |
Collapse
|