RESUMEN
The NUDIX hydrolase NUDT15 was originally implicated in sanitizing oxidized nucleotides, but was later shown to hydrolyze the active thiopurine metabolites, 6-thio-(d)GTP, thereby dictating the clinical response of this standard-of-care treatment for leukemia and inflammatory diseases. Nonetheless, its physiological roles remain elusive. Here, we sought to develop small-molecule NUDT15 inhibitors to elucidate its biological functions and potentially to improve NUDT15-dependent chemotherapeutics. Lead compound TH1760 demonstrated low-nanomolar biochemical potency through direct and specific binding into the NUDT15 catalytic pocket and engaged cellular NUDT15 in the low-micromolar range. We also employed thiopurine potentiation as a proxy functional readout and demonstrated that TH1760 sensitized cells to 6-thioguanine through enhanced accumulation of 6-thio-(d)GTP in nucleic acids. A biochemically validated, inactive structural analog, TH7285, confirmed that increased thiopurine toxicity takes place via direct NUDT15 inhibition. In conclusion, TH1760 represents the first chemical probe for interrogating NUDT15 biology and potential therapeutic avenues.
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Pirofosfatasas/antagonistas & inhibidores , Pirofosfatasas/metabolismo , Sitios de Unión , Línea Celular , Diseño de Fármacos , Desarrollo de Medicamentos , Escherichia coli , Humanos , Pirofosfatasa Inorgánica/antagonistas & inhibidores , Pirofosfatasa Inorgánica/genética , Pirofosfatasa Inorgánica/metabolismo , Modelos Moleculares , Unión Proteica , Conformación Proteica , Pirofosfatasas/química , Pirofosfatasas/genética , Relación Estructura-ActividadRESUMEN
Altered oncogene expression in cancer cells causes loss of redox homeostasis resulting in oxidative DNA damage, e.g. 8-oxoguanine (8-oxoG), repaired by base excision repair (BER). PARP1 coordinates BER and relies on the upstream 8-oxoguanine-DNA glycosylase (OGG1) to recognise and excise 8-oxoG. Here we hypothesize that OGG1 may represent an attractive target to exploit reactive oxygen species (ROS) elevation in cancer. Although OGG1 depletion is well tolerated in non-transformed cells, we report here that OGG1 depletion obstructs A3 T-cell lymphoblastic acute leukemia growth in vitro and in vivo, validating OGG1 as a potential anti-cancer target. In line with this hypothesis, we show that OGG1 inhibitors (OGG1i) target a wide range of cancer cells, with a favourable therapeutic index compared to non-transformed cells. Mechanistically, OGG1i and shRNA depletion cause S-phase DNA damage, replication stress and proliferation arrest or cell death, representing a novel mechanistic approach to target cancer. This study adds OGG1 to the list of BER factors, e.g. PARP1, as potential targets for cancer treatment.
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Neoplasias del Colon/tratamiento farmacológico , ADN Glicosilasas/genética , ADN de Neoplasias/genética , Regulación Neoplásica de la Expresión Génica , Poli(ADP-Ribosa) Polimerasa-1/inmunología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/mortalidad , Daño del ADN , ADN Glicosilasas/antagonistas & inhibidores , ADN Glicosilasas/metabolismo , Reparación del ADN/efectos de los fármacos , Replicación del ADN/efectos de los fármacos , ADN de Neoplasias/metabolismo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Guanina/análogos & derivados , Guanina/metabolismo , Células HCT116 , Humanos , Ratones , Ratones Desnudos , Terapia Molecular Dirigida , Estrés Oxidativo , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Análisis de Supervivencia , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
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 bind in 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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Enzimas Reparadoras del ADN/antagonistas & inhibidores , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Nucleótidos/metabolismo , Monoéster Fosfórico Hidrolasas/antagonistas & inhibidores , Animales , Dominio Catalítico , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cristalización , Daño del ADN , Enzimas Reparadoras del ADN/química , Enzimas Reparadoras del ADN/metabolismo , Nucleótidos de Desoxiguanina/metabolismo , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacocinética , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Femenino , Humanos , Masculino , Ratones , Modelos Moleculares , Conformación Molecular , Terapia Molecular Dirigida , Neoplasias/patología , Oxidación-Reducción/efectos de los fármacos , Monoéster Fosfórico Hidrolasas/química , Monoéster Fosfórico Hidrolasas/metabolismo , Pirimidinas/química , Pirimidinas/farmacocinética , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Pirofosfatasas/antagonistas & inhibidores , Reproducibilidad de los Resultados , Ensayos Antitumor por Modelo de Xenoinjerto , Hidrolasas NudixRESUMEN
The one-carbon metabolism enzyme bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase 2 (MTHFD2) is among the most overexpressed proteins across tumors and is widely recognized as a promising anticancer target. While MTHFD2 is mainly described as a mitochondrial protein, a new nuclear function is emerging. Here, we observe that nuclear MTHFD2 protein levels and association with chromatin increase following ionizing radiation (IR) in an ataxia telangiectasia mutated (ATM)- and DNA-dependent protein kinase (DNA-PK)-dependent manner. Furthermore, repair of IR-induced DNA double-strand breaks (DSBs) is delayed upon MTHFD2 knockdown, suggesting a role for MTHFD2 in DSB repair. In support of this, we observe impaired recruitment of replication protein A (RPA), reduced resection, decreased IR-induced DNA repair protein RAD51 homolog 1 (RAD51) levels and impaired homologous recombination (HR) activity in MTHFD2-depleted cells following IR. In conclusion, we identify a key role for MTHFD2 in HR repair and describe an interdependency between MTHFD2 and HR proficiency that could potentially be exploited for cancer therapy.
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SAMHD1 is a dNTP triphosphohydrolase governing nucleotide pool homeostasis and can detoxify chemotherapy metabolites controlling their clinical responses. To understand SAMHD1 biology and investigate the potential of targeting SAMHD1 as neoadjuvant to current chemotherapies, we set out to discover selective small-molecule inhibitors. Here, we report a discovery pipeline encompassing a biochemical screening campaign and a set of complementary biochemical, biophysical, and cell-based readouts for rigorous characterization of the screen output. The identified small molecules, TH6342 and analogs, accompanied by inactive control TH7126, demonstrated specific, low µM potency against both physiological and oncology-drug-derived substrates. By coupling kinetic studies with thermal shift assays, we reveal the inhibitory mechanism of TH6342 and analogs, which engage pre-tetrameric SAMHD1 and deter oligomerization and allosteric activation without occupying nucleotide-binding pockets. Altogether, our study diversifies inhibitory modes against SAMHD1, and the discovery pipeline reported herein represents a thorough framework for future SAMHD1 inhibitor development.
RESUMEN
8-oxo Guanine DNA Glycosylase 1 is the initiating enzyme within base excision repair and removes oxidized guanines from damaged DNA. Since unrepaired 8-oxoG could lead to G : CâT : A transversion, base removal is of utmost importance for cells to ensure genomic integrity. For cells with elevated levels of reactive oxygen species this dependency is further increased. In the past we and others have validated OGG1 as a target for inhibitors to treat cancer and inflammation. Here, we present the optimization campaign that led to the broadly used tool compound TH5487. Based on results from a small molecule screening campaign, we performed hit to lead expansion and arrived at potent and selective substituted N-piperidinyl-benzimidazolones. Using X-ray crystallography data, we describe the surprising binding mode of the most potent member of the class, TH8535. Here, the N-Piperidinyl-linker adopts a chair instead of a boat conformation which was found for weaker analogues. We further demonstrate cellular target engagement and efficacy of TH8535 against a number of cancer cell lines.
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ADN Glicosilasas , Neoplasias , Humanos , ADN Glicosilasas/química , ADN Glicosilasas/genética , ADN Glicosilasas/metabolismo , Guanina/química , Guanina/metabolismo , Reparación del ADN , Bencimidazoles/farmacología , Daño del ADNRESUMEN
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.
Asunto(s)
Metilenotetrahidrofolato Deshidrogenasa (NADP) , Neoplasias , Metilenotetrahidrofolato Deshidrogenasa (NADP)/genética , Metilenotetrahidrofolato Deshidrogenasa (NADP)/metabolismo , Ácido Fólico/metabolismo , Formiatos , Purinas , TetrahidrofolatosRESUMEN
Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a mitochondrial 1-carbon metabolism enzyme, which is an attractive anticancer drug target as it is highly upregulated in cancer but is not expressed in healthy adult cells. Selective MTHFD2 inhibitors could therefore offer reduced side-effects during treatment, which are common with antifolate drugs that target other 1C-metabolism enzymes. This task is challenging however, as MTHFD2 shares high sequence identity with the constitutively expressed isozymes cytosolic MTHFD1 and mitochondrial MTHFD2L. In fact, one of the most potent MTHFD2 inhibitors reported to date, TH7299, is actually more active against MTHFD1 and MTHFD2L. While structures of MTHFD2 and MTHFD1 exist, no MTHFD2L structures are available. We determined the first structure of MTHFD2L and its complex with TH7299, which reveals the structural basis for its highly potent MTHFD2L inhibition. Detailed analysis of the MTHFD2L structure presented here clearly highlights the challenges associated with developing truly isoform-selective MTHFD2 inhibitors.
Asunto(s)
Antineoplásicos , Antagonistas del Ácido Fólico , Metilenotetrahidrofolato Deshidrogenasa (NADP)/química , Carbono , Humanos , Isoenzimas/metabolismo , Metilenotetrahidrofolato Deshidrogenasa (NADP)/metabolismoRESUMEN
Oxidative DNA damage is recognized by 8-oxoguanine (8-oxoG) DNA glycosylase 1 (OGG1), which excises 8-oxoG, leaving a substrate for apurinic endonuclease 1 (APE1) and initiating repair. Here, we describe a small molecule (TH10785) that interacts with the phenylalanine-319 and glycine-42 amino acids of OGG1, increases the enzyme activity 10-fold, and generates a previously undescribed ß,δ-lyase enzymatic function. TH10785 controls the catalytic activity mediated by a nitrogen base within its molecular structure. In cells, TH10785 increases OGG1 recruitment to and repair of oxidative DNA damage. This alters the repair process, which no longer requires APE1 but instead is dependent on polynucleotide kinase phosphatase (PNKP1) activity. The increased repair of oxidative DNA lesions with a small molecule may have therapeutic applications in various diseases and aging.
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Daño del ADN , ADN Glicosilasas , Reparación del ADN , Estrés Oxidativo , Biocatálisis/efectos de los fármacos , Daño del ADN/efectos de los fármacos , ADN Glicosilasas/química , ADN Glicosilasas/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Activación Enzimática , Glicina/química , Humanos , Ligandos , Estrés Oxidativo/genética , Fenilalanina/química , Especificidad por SustratoRESUMEN
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.
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Aminohidrolasas , Leucemia Mieloide Aguda , Aminohidrolasas/genética , Humanos , Hidrolasas , Leucemia Mieloide Aguda/tratamiento farmacológico , Metilenotetrahidrofolato Deshidrogenasa (NADP)/genética , Enzimas Multifuncionales/genética , TimidinaRESUMEN
Acute myeloid leukemia (AML) is an aggressive hematologic malignancy, exhibiting high levels of reactive oxygen species (ROS). ROS levels have been suggested to drive leukemogenesis and is thus a potential novel target for treating AML. MTH1 prevents incorporation of oxidized nucleotides into the DNA to maintain genome integrity and is upregulated in many cancers. Here we demonstrate that hematologic cancers are highly sensitive to MTH1 inhibitor TH1579 (karonudib). A functional precision medicine ex vivo screen in primary AML bone marrow samples demonstrated a broad response profile of TH1579, independent of the genomic alteration of AML, resembling the response profile of the standard-of-care treatments cytarabine and doxorubicin. Furthermore, TH1579 killed primary human AML blast cells (CD45+) as well as chemotherapy resistance leukemic stem cells (CD45+Lin-CD34+CD38-), which are often responsible for AML progression. TH1579 killed AML cells by causing mitotic arrest, elevating intracellular ROS levels, and enhancing oxidative DNA damage. TH1579 showed a significant therapeutic window, was well tolerated in animals, and could be combined with standard-of-care treatments to further improve efficacy. TH1579 significantly improved survival in two different AML disease models in vivo. In conclusion, the preclinical data presented here support that TH1579 is a promising novel anticancer agent for AML, providing a rationale to investigate the clinical usefulness of TH1579 in AML in an ongoing clinical phase I trial. SIGNIFICANCE: The MTH1 inhibitor TH1579 is a potential novel AML treatment, targeting both blasts and the pivotal leukemic stem cells while sparing normal bone marrow cells.
Asunto(s)
Crisis Blástica/tratamiento farmacológico , Enzimas Reparadoras del ADN/antagonistas & inhibidores , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Leucemia Mieloide Aguda/tratamiento farmacológico , Mitosis , Células Madre Neoplásicas/efectos de los fármacos , Monoéster Fosfórico Hidrolasas/antagonistas & inhibidores , Pirimidinas/farmacología , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis , Crisis Blástica/genética , Crisis Blástica/metabolismo , Crisis Blástica/patología , Proliferación Celular , Citarabina/administración & dosificación , Doxorrubicina/administración & dosificación , Femenino , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Pronóstico , Especies Reactivas de Oxígeno/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Computational chemistry has now been widely accepted as a useful tool for shortening lead times in early drug discovery. When selecting new potential drug targets, it is important to assess the likelihood of finding suitable starting points for lead generation before pursuing costly high-throughput screening campaigns. By exploiting available high-resolution crystal structures, an in silico druggability assessment can facilitate the decision of whether, and in cases where several protein family members exist, which of these to pursue experimentally. Many of the algorithms and software suites commonly applied for in silico druggability assessment are complex, technically challenging and not always user-friendly. Here we applied the intuitive open access servers of DoGSite, FTMap and CryptoSite to comprehensively predict ligand binding pockets, druggability scores and conformationally active regions of the NUDIX protein family. In parallel we analyzed potential ligand binding sites, their druggability and pocket parameter using Schrödinger's SiteMap. Then an in silico docking cascade of a subset of the ZINC FragNow library using the Glide docking program was performed to assess identified pockets for large-scale small-molecule binding. Subsequently, this initial dual ranking of druggable sites within the NUDIX protein family was benchmarked against experimental hit rates obtained both in-house and by others from traditional biochemical and fragment screening campaigns. The observed correlation suggests that the presented user-friendly workflow of a dual parallel in silico druggability assessment is applicable as a standalone method for decision on target prioritization and exclusion in future screening campaigns.
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Recent RNA virus outbreaks such as Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Ebola virus (EBOV) have caused worldwide health emergencies highlighting the urgent need for new antiviral strategies. Targeting host cell pathways supporting viral replication is an attractive approach for development of antiviral compounds, especially with new, unexplored viruses where knowledge of virus biology is limited. Here, we present a strategy to identify host-targeted small molecule inhibitors using an image-based phenotypic antiviral screening assay followed by extensive target identification efforts revealing altered cellular pathways upon antiviral compound treatment. The newly discovered antiviral compounds showed broad-range antiviral activity against pathogenic RNA viruses such as SARS-CoV-2, EBOV and Crimean-Congo hemorrhagic fever virus (CCHFV). Target identification of the antiviral compounds by thermal protein profiling revealed major effects on proteostasis pathways and disturbance in interactions between cellular HSP70 complex and viral proteins, illustrating the supportive role of HSP70 on many RNA viruses across virus families. Collectively, this strategy identifies new small molecule inhibitors with broad antiviral activity against pathogenic RNA viruses, but also uncovers novel virus biology urgently needed for design of new antiviral therapies.
Asunto(s)
Antivirales/farmacología , Interacciones Huésped-Patógeno/efectos de los fármacos , Virus ARN/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Animales , Línea Celular , Ebolavirus/efectos de los fármacos , Ebolavirus/fisiología , Proteínas HSP70 de Choque Térmico/metabolismo , Virus de la Fiebre Hemorrágica de Crimea-Congo/efectos de los fármacos , Virus de la Fiebre Hemorrágica de Crimea-Congo/fisiología , Humanos , Unión Proteica/efectos de los fármacos , Estabilidad Proteica , Proteoma/efectos de los fármacos , Proteostasis/efectos de los fármacos , Infecciones por Virus ARN/metabolismo , Infecciones por Virus ARN/virología , Virus ARN/fisiología , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/fisiología , Bibliotecas de Moléculas Pequeñas/farmacología , Proteínas Virales/metabolismoRESUMEN
The deoxycytidine analogue cytarabine (ara-C) remains the backbone treatment of acute myeloid leukaemia (AML) as well as other haematological and lymphoid malignancies, but must be combined with other chemotherapeutics to achieve cure. Yet, the underlying mechanism dictating synergistic efficacy of combination chemotherapy remains largely unknown. The dNTPase SAMHD1, which regulates dNTP homoeostasis antagonistically to ribonucleotide reductase (RNR), limits ara-C efficacy by hydrolysing the active triphosphate metabolite ara-CTP. Here, we report that clinically used inhibitors of RNR, such as gemcitabine and hydroxyurea, overcome the SAMHD1-mediated barrier to ara-C efficacy in primary blasts and mouse models of AML, displaying SAMHD1-dependent synergy with ara-C. We present evidence that this is mediated by dNTP pool imbalances leading to allosteric reduction of SAMHD1 ara-CTPase activity. Thus, SAMHD1 constitutes a novel biomarker for combination therapies of ara-C and RNR inhibitors with immediate consequences for clinical practice to improve treatment of AML.
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Citarabina/farmacología , Leucemia Mieloide Aguda , Pirofosfatasas/metabolismo , Ribonucleótido Reductasas/antagonistas & inhibidores , Proteína 1 que Contiene Dominios SAM y HD/metabolismo , Animales , Trifosfato de Arabinofuranosil Citosina/metabolismo , RatonesRESUMEN
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.
RESUMEN
The glycolytic PFKFB3 enzyme is widely overexpressed in cancer cells and an emerging anti-cancer 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-γH2AX-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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Antineoplásicos/farmacología , Compuestos de Bifenilo/farmacología , Inhibidores Enzimáticos/farmacología , Hidroxibenzoatos/farmacología , Neoplasias/terapia , Fosfofructoquinasa-2/antagonistas & inhibidores , Sulfonas/farmacología , Antineoplásicos/uso terapéutico , Compuestos de Bifenilo/uso terapéutico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Quimioradioterapia/métodos , Roturas del ADN de Doble Cadena/efectos de la radiación , Didesoxinucleótidos/metabolismo , Inhibidores Enzimáticos/uso terapéutico , Humanos , Hidroxibenzoatos/uso terapéutico , Fosfofructoquinasa-2/genética , Fosfofructoquinasa-2/metabolismo , ARN Interferente Pequeño/metabolismo , Tolerancia a Radiación/efectos de los fármacos , Tolerancia a Radiación/genética , Radiación Ionizante , Reparación del ADN por Recombinación/efectos de los fármacos , Reparación del ADN por Recombinación/efectos de la radiación , Sulfonas/uso terapéuticoRESUMEN
The onset of inflammation is associated with reactive oxygen species and oxidative damage to macromolecules like 7,8-dihydro-8-oxoguanine (8-oxoG) in DNA. Because 8-oxoguanine DNA glycosylase 1 (OGG1) binds 8-oxoG and because Ogg1-deficient mice are resistant to acute and systemic inflammation, we hypothesized that OGG1 inhibition may represent a strategy for the prevention and treatment of inflammation. We developed TH5487, a selective active-site inhibitor of OGG1, which hampers OGG1 binding to and repair of 8-oxoG and which is well tolerated by mice. TH5487 prevents tumor necrosis factor-α-induced OGG1-DNA interactions at guanine-rich promoters of proinflammatory genes. This, in turn, decreases DNA occupancy of nuclear factor κB and proinflammatory gene expression, resulting in decreased immune cell recruitment to mouse lungs. Thus, we present a proof of concept that targeting oxidative DNA repair can alleviate inflammatory conditions in vivo.
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Antiinflamatorios no Esteroideos/farmacología , Bencimidazoles/farmacología , ADN Glicosilasas/antagonistas & inhibidores , Inhibidores Enzimáticos/uso terapéutico , Expresión Génica/efectos de los fármacos , Inflamación/tratamiento farmacológico , Piperidinas/farmacología , Animales , Antiinflamatorios no Esteroideos/uso terapéutico , Bencimidazoles/uso terapéutico , ADN Glicosilasas/metabolismo , Reparación del ADN/efectos de los fármacos , Reparación del ADN/genética , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Técnicas de Inactivación de Genes , Guanina/análogos & derivados , Guanina/antagonistas & inhibidores , Guanina/metabolismo , Células HEK293 , Humanos , Inflamación/genética , Células Jurkat , Ratones , Ratones Mutantes , FN-kappa B/genética , FN-kappa B/metabolismo , Piperidinas/uso terapéutico , Regiones Promotoras Genéticas , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
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. Cancer Res; 77(4); 937-48. ©2017 AACR.
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Inhibidores Enzimáticos/química , Meteniltetrahidrofolato Ciclohidrolasa/química , Metilenotetrahidrofolato Deshidrogenasa (NADP)/química , Mitocondrias/enzimología , Sitios de Unión , Cristalización , Ácido Fólico/análogos & derivados , Ácido Fólico/metabolismo , Humanos , Leucovorina/análogos & derivados , Leucovorina/metabolismo , Meteniltetrahidrofolato Ciclohidrolasa/antagonistas & inhibidores , Metilenotetrahidrofolato Deshidrogenasa (NADP)/antagonistas & inhibidores , Antígenos de Histocompatibilidad Menor , NAD/metabolismo , Multimerización de ProteínaRESUMEN
The antimetabolite 5-Fluorouracil (5-FU) is used in the treatment of various forms of cancer and has a complex mode of action. Despite 6 decades in clinical application the contribution of 5-FdUTP and dUTP [(5-F)dUTP] and 5-FUTP misincorporation into DNA and RNA respectively, for 5-FU-induced toxicity is still under debate.This study investigates DNA replication defects induced by 5-FU treatment and how (5-F)dUTP accumulation contributes to this effect. We reveal that 5-FU treatment leads to extensive problems in DNA replication fork progression, causing accumulation of cells in S-phase, DNA damage and ultimately cell death. Interestingly, these effects can be reinforced by either depletion or inhibition of the deoxyuridine triphosphatase (dUTPase, also known as DUT), highlighting the importance of (5-F)dUTP accumulation for cytotoxicity.With this study, we not only extend the current understanding of the mechanism of action of 5-FU, but also contribute to the characterization of dUTPase inhibitors. We demonstrate that pharmacological inhibition of dUTPase is a promising approach that may improve the efficacy of 5-FU treatment in the clinic.