| 1. |
- Bonagas, Nadilly, et al.
(författare)
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Pharmacological targeting of MTHFD2 suppresses acute myeloid leukemia by inducing thymidine depletion and replication stress
- 2022
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Ingår i: NATURE CANCER. - : Springer Science and Business Media LLC. - 2662-1347. ; 3:2, s. 156-
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Tidskriftsartikel (refereegranskat)abstract
- The folate metabolism enzyme MTHFD2 (methylenetetrahydrofolate dehydrogenase/cyclohydrolase) is consistently overexpressed in cancer but its roles are not fully characterized, and current candidate inhibitors have limited potency for clinical development. In the present study, we demonstrate a role for MTHFD2 in DNA replication and genomic stability in cancer cells, and perform a drug screen to identify potent and selective nanomolar MTHFD2 inhibitors; protein cocrystal structures demonstrated binding to the active site of MTHFD2 and target engagement. MTHFD2 inhibitors reduced replication fork speed and induced replication stress followed by S-phase arrest and apoptosis of acute myeloid leukemia cells in vitro and in vivo, with a therapeutic window spanning four orders of magnitude compared with nontumorigenic cells. Mechanistically, MTHFD2 inhibitors prevented thymidine production leading to misincorporation of uracil into DNA and replication stress. Overall, these results demonstrate a functional link between MTHFD2-dependent cancer metabolism and replication stress that can be exploited therapeutically with this new class of inhibitors. Helleday and colleagues describe a nanomolar MTHFD2 inhibitor that causes replication stress and DNA damage accumulation in cancer cells via thymidine depletion, demonstrating a potential therapeutic strategy in AML tumors in vivo.
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| 2. |
- Gad, Helge, et al.
(författare)
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MTH1 inhibition eradicates cancer by preventing sanitation of the dNTP pool
- 2014
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 508:7495, s. 215-221
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Tidskriftsartikel (refereegranskat)abstract
- Cancers have dysfunctional redox regulation resulting in reactive oxygen species production, damaging both DNA and free dNTPs. The MTH1 protein sanitizes oxidized dNTP pools to prevent incorporation of damaged bases during DNA replication. Although MTH1 is non-essential in normal cells, we show that cancer cells require MTH1 activity to avoid incorporation of oxidized dNTPs, resulting in DNA damage and cell death. We validate MTH1 as an anticancer target in vivo and describe small molecules TH287 and TH588 as first-in-class nudix hydrolase family inhibitors that potently and selectively engage and inhibit the MTH1 protein in cells. Protein co-crystal structures demonstrate that the inhibitors bindin the active site of MTH1. The inhibitors cause incorporation of oxidized dNTPs in cancer cells, leading to DNA damage, cytotoxicity and therapeutic responses in patient-derived mouse xenografts. This study exemplifies the non-oncogene addiction concept for anticancer treatment and validates MTH1 as being cancer phenotypic lethal.
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| 3. |
- Green, Alanna C., et al.
(författare)
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Formate overflow drives toxic folate trapping in MTHFD1 inhibited cancer cells
- 2023
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Ingår i: Nature Metabolism. - : Springer Nature. - 2522-5812. ; 5:4, s. 642-659
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Tidskriftsartikel (refereegranskat)abstract
- Cancer cells fuel their increased need for nucleotide supply by upregulating one-carbon (1C) metabolism, including the enzymes methylenetetrahydrofolate dehydrogenase–cyclohydrolase 1 and 2 (MTHFD1 and MTHFD2). TH9619 is a potent inhibitor of dehydrogenase and cyclohydrolase activities in both MTHFD1 and MTHFD2, and selectively kills cancer cells. Here, we reveal that, in cells, TH9619 targets nuclear MTHFD2 but does not inhibit mitochondrial MTHFD2. Hence, overflow of formate from mitochondria continues in the presence of TH9619. TH9619 inhibits the activity of MTHFD1 occurring downstream of mitochondrial formate release, leading to the accumulation of 10-formyl-tetrahydrofolate, which we term a ‘folate trap’. This results in thymidylate depletion and death of MTHFD2-expressing cancer cells. This previously uncharacterized folate trapping mechanism is exacerbated by physiological hypoxanthine levels that block the de novo purine synthesis pathway, and additionally prevent 10-formyl-tetrahydrofolate consumption for purine synthesis. The folate trapping mechanism described here for TH9619 differs from other MTHFD1/2 inhibitors and antifolates. Thus, our findings uncover an approach to attack cancer and reveal a regulatory mechanism in 1C metabolism.
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| 4. |
- Gustafsson, Nina M. S., et al.
(författare)
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Targeting PFKFB3 radiosensitizes cancer cells and suppresses homologous recombination
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The glycolytic PFKFB3 enzyme is widely overexpressed in cancer cells and an emerging anticancer target. Here, we identify PFKFB3 as a critical factor in homologous recombination (HR) repair of DNA double-strand breaks. PFKFB3 rapidly relocates into ionizing radiation (IR)-induced nuclear foci in an MRN-ATM-gamma H2AX-MDC1-dependent manner and co-localizes with DNA damage and HR repair proteins. PFKFB3 relocalization is critical for recruitment of HR proteins, HR activity, and cell survival upon IR. We develop KAN0438757, a small molecule inhibitor that potently targets PFKFB3. Pharmacological PFKFB3 inhibition impairs recruitment of ribonucleotide reductase M2 and deoxynucleotide incorporation upon DNA repair, and reduces dNTP levels. Importantly, KAN0438757 induces radiosensitization in transformed cells while leaving non-transformed cells unaffected. In summary, we identify a key role for PFKFB3 enzymatic activity in HR repair and present KAN0438757, a selective PFKFB3 inhibitor that could potentially be used as a strategy for the treatment of cancer.
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| 5. |
- Gustafsson, Robert, et al.
(författare)
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Crystal Structure of the Emerging Cancer Target MTHFD2 in Complex with a Substrate-Based Inhibitor
- 2017
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Ingår i: Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 0008-5472 .- 1538-7445. ; 77:4, s. 937-948
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Tidskriftsartikel (refereegranskat)abstract
- To sustain their proliferation, cancer cells become dependent on one-carbon metabolism to support purine and thymidylate synthesis. Indeed, one of the most highly upregulated enzymes during neoplastic transformation is MTHFD2, a mitochondrial methylenetetrahydrofolate dehydrogenase and cyclohydrolase involved in one-carbon metabolism. Because MTHFD2 is expressed normally only during embryonic development, it offers a disease-selective therapeutic target for eradicating cancer cells while sparing healthy cells. Here we report the synthesis and preclinical characterization of the first inhibitor of human MTHFD2. We also disclose the first crystal structure of MTHFD2 in complex with a substrate-based inhibitor and the enzyme cofactors NAD(+) and inorganic phosphate. Our work provides a rationale for continued development of a structural framework for the generation of potent and selective MTHFD2 inhibitors for cancer treatment.
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| 6. |
- Herold, Nikolas, et al.
(författare)
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Targeting SAMHD1 with the Vpx protein to improve cytarabine therapy for hematological malignancies
- 2017
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 23:2, s. 256-263
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Tidskriftsartikel (refereegranskat)abstract
- The cytostatic deoxycytidine analog cytarabine (ara-C) is the most active agent available against acute myelogenous leukemia (AML). Together with anthracyclines, ara-C forms the backbone of AML treatment for children and adults'. In AML, both the cytotoxicity of ara-C in vitro and the clinical response to ara-C therapy are correlated with the ability of AML blasts to accumulate the active metabolite ara-C triphosphate (ara-CTP)(2-5), which causes DNA damage through perturbation of DNA synthesis(6). Differences in expression levels of known transporters or metabolic enzymes relevant to ara-C only partially account for patient-specific differential ara-CTP accumulation in AML blasts and response to ara-C treatment(7-9). Here we demonstrate that the deoxynucleoside triphosphate (dNTP) triphosphohydrolase SAM domain and HD domain 1 (SAMHD1) promotes the detoxification of intracellular ara-CTP pools. Recombinant SAMHD1 exhibited ara-CTPase activity in vitro, and cells in which SAMHD1 expression was transiently reduced by treatment with the simian immunodeficiency virus (SIV) protein Vpx were dramatically more sensitive to ara-C-induced cytotoxicity. CRISPR-Cas9-mediated disruption of the gene encoding SAMHD1 sensitized cells to ara-C, and this sensitivity could be abrogated by ectopic expression of wild-type (WT), but not dNTPase-deficient, SAMHD1. Mouse models of AML lacking SAMHD1 were hypersensitive to ara-C, and treatment ex vivo with Vpx sensitized primary patient derived AML blasts to ara-C. Finally, we identified SAMHD1 as a risk factor in cohorts of both pediatric and adult patients with de novo AML who received ara-C treatment. Thus, SAMHD1 expression levels dictate patient sensitivity to ara-C, providing proof-of-concept that the targeting of SAMHD1 by Vpx could be an attractive therapeutic strategy for potentiating ara-C efficacy in hematological malignancies.
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| 7. |
- Llona-Minguez, Sabin, et al.
(författare)
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Discovery of the First Potent and Selective Inhibitors of Human dCTP Pyrophosphatase 1
- 2016
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 59:3, s. 1140-1148
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Tidskriftsartikel (refereegranskat)abstract
- The dCTPase pyrophosphatase 1 (dCTPase) regulates the intracellular nucleotide pool through hydrolytic degradation of canonical and noncanonical nucleotide triphosphates (dNTPs). dCTPase is highly expressed in multiple carcinomas and is associated with cancer cell sternness. Here we report on the development of the first potent and selective dCTPase inhibitors that enhance the cytotoxic effect of cytidine analogues in leukemia cells. Boronate 30 displays a promising in vitro ADME profile, including plasma and mouse microsomal half-lives, aqueous solubility, cell permeability and CYP inhibition, deeming it a suitable compound for in vivo studies.
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| 8. |
- Llona-Minguez, Sabin, et al.
(författare)
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Identification of Triazolothiadiazoles as Potent Inhibitors of the dCTP Pyrophosphatase 1
- 2017
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 60:5, s. 2148-2154
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Tidskriftsartikel (refereegranskat)abstract
- The dCTP pyrophosphatase 1 (dCTPase) is involved in the regulation of the cellular dNTP pool and has been linked to cancer progression. Here we report on the discovery of a series of 3,6-disubstituted triazolothiadiazoles as potent dCTPase inhibitors. Compounds 16 and 18 display good correlation between enzymatic inhibition and target engagement, together with efficacy in a cellular synergy model, deeming them as a promising starting point for hit -to-lead development.
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| 9. |
- Luttens, Andreas, et al.
(författare)
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Virtual Fragment Screening for DNA Repair Inhibitors in Vast Chemical Space
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Fragment-based screening can catalyze drug discovery by identifying novel scaffolds, but this approach is limited by the small chemical libraries studied by biophysical experiments and the challenging hit optimization step. In efforts to identify DNA repair inhibitors, we explored the use of structure-based virtual screening to access ultralarge fragment libraries that cover four orders of magnitude larger fractions of chemical space than traditional techniques. A set of 14 million fragments were docked to 8-oxoguanine DNA glycosylase (OGG1), a challenging drug target involved in cancer and inflammation. Of the 29 top-ranked fragments that were experimentally evaluated, four compounds were shown to bind to OGG1 and X-ray crystallography confirmed the predicted binding modes. Docking of readily synthesizable elaborations guided fragment optimization, leading to the discovery of submicromolar OGG1 inhibitors with anti-inflammatory and anti-cancer effects in cell models. Our results demonstrate that fragment-based virtual screening enables efficient exploration of vast chemical libraries.
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| 10. |
- Michel, Maurice, et al.
(författare)
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Computational and Experimental Druggability Assessment of Human DNA Glycosylases
- 2019
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Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 4:7, s. 11642-11656
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Tidskriftsartikel (refereegranskat)abstract
- Due to a polar or even charged binding interface, DNA-binding proteins are considered extraordinarily difficult targets for development of small-molecule ligands and only a handful of proteins have been targeted successfully to date. Recently, however, it has been shown that development of selective and efficient inhibitors of 8-oxoguanine DNA glycosylase is possible. Here, we describe the initial druggability assessment of DNA glycosylases in a computational setting and experimentally investigate several methods to target endonuclease VIII-like 1 (NEIL1) with small-molecule inhibitors. We find that DNA glycosylases exhibit good predicted druggability in both DNA-bound and -unbound states. Furthermore, we find catalytic sites to be highly flexible, allowing for a range of interactions and binding partners. One flexible catalytic site was rationalized for NEIL1 and further investigated experimentally using both a biochemical assay in the presence of DNA and a thermal shift assay in the absence of DNA.
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