Assuntos
Antineoplásicos , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Desenho Assistido por Computador , Relação Dose-Resposta a Droga , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacologia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/metabolismo , Estrutura Molecular , Relação Estrutura-Atividade , Mutações Sintéticas Letais , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/química , Metionina Adenosiltransferase/metabolismoRESUMO
Methionine adenosyltransferase 2 A (MAT2A) mediates the synthesis of methyl donor S-Adenosylmethionine (SAM), providing raw materials for methylation reactions in cells. MAT2A inhibitors are currently used for the treatment of tumors with methylthioadenosine phosphorylase (MTAP) deficiency in clinical research. Methyltransferase like 3 (METTL3) catalyzes N6-methyladenosine (m6A) modification of mRNA in mammalian cells using SAM as the substrate which has been shown to affect the tumorigenesis of non-small cell lung cancer (NSCLC) from multiple perspectives. MAT2A-induced SAM depletion may have the potential to inhibit the methyl transfer function of METTL3. Therefore, in order to expand the applicability of inhibitors, improve anti-tumor effects and reduce toxicity, the combinational effect of MAT2A inhibitor AG-270 and METTL3 inhibitor STM2457 was evaluated in NSCLC. The results showed that this combination induced cell apoptosis rather than cell cycle arrest, which was non-tissue-specific and was independent of MTAP expression status, resulting in a significant synergistic anti-tumor effect. We further elucidated that the combination-induced enhanced apoptosis was associated with the decreased m6A level, leading to downregulation of PI3K/AKT protein, ultimately activating the apoptosis-related proteins. Unexpectedly, although combination therapy resulted in metabolic recombination, no significant change in methionine metabolic metabolites was found. More importantly, the combination also exerted synergistic effects in vivo. In summary, the combination of MAT2A inhibitor and METTL3 inhibitor showed synergistic effects both in vivo and in vitro, which laid a theoretical foundation for expanding the clinical application research of the two types of drugs.
Assuntos
Apoptose , Carcinoma Pulmonar de Células não Pequenas , Sinergismo Farmacológico , Neoplasias Pulmonares , Metionina Adenosiltransferase , Metiltransferases , Animais , Humanos , Camundongos , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Metionina Adenosiltransferase/metabolismo , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/genética , Metiltransferases/metabolismo , Metiltransferases/antagonistas & inibidores , Camundongos Endogâmicos BALB C , Camundongos Nus , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Synthetic lethality has recently emerged as a new approach for the treatment of mutated genes that were previously considered undruggable. Targeting methionine adenosyltransferase 2A (MAT2A) in cancers with deletion of the methylthioadenosine phosphorylase (MTAP) gene leads to synthetic lethality and thus has attracted significant interest in the field of precise anticancer drug development. Herein, we report the discovery of a series of novel MAT2A inhibitors featuring a pyrazolo[3,4-c]quinolin-4-one skeleton based on structure-based drug design. Further optimization led to compound 39, which has a high potency for inhibiting MAT2A and a remarkable selectivity for MTAP-deleted cancer cell lines. Compound 39 has a favorable pharmacokinetic profile with high plasma exposure and oral bioavailability, and it exhibits significant efficacy in xenograft MTAP-depleted models. Moreover, 39 demonstrates excellent brain exposure with a Kpuu of 0.64 in rats.
Assuntos
Encéfalo , Desenho de Fármacos , Inibidores Enzimáticos , Metionina Adenosiltransferase , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/metabolismo , Humanos , Animais , Relação Estrutura-Atividade , Ratos , Encéfalo/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/síntese química , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/farmacocinética , Antineoplásicos/química , Antineoplásicos/síntese química , Camundongos , Masculino , Ratos Sprague-Dawley , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Targeting the metabolic dependencies of acute myeloid leukemia (AML) cells is a promising therapeutical strategy. In particular, the cysteine and methionine metabolism pathway (C/M) is significantly altered in AML cells compared to healthy blood cells. Moreover, methionine has been identified as one of the dominant amino acid dependencies of AML cells. Through RNA-seq, we found that the two nucleoside analogs 8-chloro-adenosine (8CA) and 8-amino-adenosine (8AA) significantly suppress the C/M pathway in AML cells, and methionine-adenosyltransferase-2A (MAT2A) is one of most significantly downregulated genes. Additionally, mass spectrometry analysis revealed that Venetoclax (VEN), a BCL-2 inhibitor recently approved by the FDA for AML treatment, significantly decreases the intracellular level of methionine in AML cells. Based on these findings, we hypothesized that combining 8CA or 8AA with VEN can efficiently target the Methionine-MAT2A-S-adenosyl-methionine (SAM) axis in AML. Our results demonstrate that VEN and 8CA/8AA synergistically decrease the SAM biosynthesis and effectively target AML cells both in vivo and in vitro. These findings suggest the promising potential of combining 8CA/8AA and VEN for AML treatment by inhibiting Methionine-MAT2A-SAM axis and provide a strong rationale for our recently activated clinical trial.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Sinergismo Farmacológico , Leucemia Mieloide Aguda , Metionina Adenosiltransferase , Metionina , S-Adenosilmetionina , Sulfonamidas , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Humanos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Sulfonamidas/farmacologia , Metionina/metabolismo , Metionina/análogos & derivados , Metionina Adenosiltransferase/metabolismo , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/genética , Animais , Camundongos , S-Adenosilmetionina/farmacologia , S-Adenosilmetionina/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular TumoralRESUMO
The methionine adenosyltransferase MAT2A catalyzes the synthesis ofthe methyl donor S-adenosylmethionine (SAM) and thereby regulates critical aspects of metabolism and transcription. Aberrant MAT2A function can lead to metabolic and transcriptional reprogramming of cancer cells, and MAT2A has been shown to promote survival of MTAP-deficient tumors, a genetic alteration that occurs in â¼ 13 % of all tumors. Thus, MAT2A holds great promise as a novel anticancer target. Here, we report a novel series of MAT2A inhibitors generated by a fragment growing approach from AZ-28, a low-molecular weight MAT2A inhibitor with promising pre-clinical properties. X-ray co-crystal structure revealed that compound 7 fully occupies the allosteric pocket of MAT2A as a single molecule mimicking MAT2B. By introducing additional backbone interactions and rigidifying the requisite linker extensions, we generated compound 8, which exhibited single digit nanomolar enzymatic and sub-micromolar cellular inhibitory potency for MAT2A.
Assuntos
Metionina Adenosiltransferase , Neoplasias , Humanos , Sítio Alostérico , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/metabolismo , Mutação , S-Adenosilmetionina/metabolismoRESUMO
Homozygous 5'-methylthioadenosine phosphorylase (MTAP) deletions occur in approximately 15% of human cancers. Co-deletion of MTAP and methionine adenosyltransferase 2 alpha (MAT2a) induces a synthetic lethal phenotype involving protein arginine methyltransferase 5 (PRMT5) inhibition. MAT2a inhibitors are now in clinical trials for genotypic MTAP-/- cancers, however the MTAP-/- genotype represents fewer than 2% of human colorectal cancers (CRCs), limiting the utility of MAT2a inhibitors in these and other MTAP+/+ cancers. Methylthio-DADMe-immucillin-A (MTDIA) is a picomolar transition state analog inhibitor of MTAP that renders cells enzymatically MTAP-deficient to induce the MTAP-/- phenotype. Here, we demonstrate that MTDIA and MAT2a inhibitor AG-270 combination therapy mimics synthetic lethality in MTAP+/+ CRC cell lines with similar effects in mouse xenografts and without adverse histology on normal tissues. Combination treatment is synergistic with a 104-fold increase in drug potency for inhibition of CRC cell growth in culture. Combined MTDIA and AG-270 decreases S-adenosyl-L-methionine and increases 5'-methylthioadenosine in cells. The increased intracellular methylthioadenosine:S-adenosyl-L-methionine ratio inhibits PRMT5 activity, leading to cellular arrest and apoptotic cell death by causing MDM4 alternative splicing and p53 activation. Combination MTDIA and AG-270 treatment differs from direct inhibition of PRMT5 by GSK3326595 by avoiding toxicity caused by cell death in the normal gut epithelium induced by the PRMT5 inhibitor. The combination of MTAP and MAT2a inhibitors expands this synthetic lethal approach to include MTAP+/+ cancers, especially the remaining 98% of CRCs without the MTAP-/- genotype.
Assuntos
Desoxiadenosinas , Metionina Adenosiltransferase , Neoplasias , Proteína-Arginina N-Metiltransferases , Purina-Núcleosídeo Fosforilase , S-Adenosilmetionina , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxiadenosinas/antagonistas & inibidores , Desoxiadenosinas/genética , Desoxiadenosinas/metabolismo , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Neoplasias/genética , Neoplasias/fisiopatologia , Neoplasias/terapia , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Purina-Núcleosídeo Fosforilase/genética , Purina-Núcleosídeo Fosforilase/metabolismo , Pirrolidinas/farmacologia , Pirrolidinas/uso terapêutico , S-Adenosilmetionina/metabolismoRESUMO
One-carbon metabolism is an essential branch of cellular metabolism that intersects with epigenetic regulation. In this work, we show how formaldehyde (FA), a one-carbon unit derived from both endogenous sources and environmental exposure, regulates one-carbon metabolism by inhibiting the biosynthesis of S-adenosylmethionine (SAM), the major methyl donor in cells. FA reacts with privileged, hyperreactive cysteine sites in the proteome, including Cys120 in S-adenosylmethionine synthase isoform type-1 (MAT1A). FA exposure inhibited MAT1A activity and decreased SAM production with MAT-isoform specificity. A genetic mouse model of chronic FA overload showed a decrease n SAM and in methylation on selected histones and genes. Epigenetic and transcriptional regulation of Mat1a and related genes function as compensatory mechanisms for FA-dependent SAM depletion, revealing a biochemical feedback cycle between FA and SAM one-carbon units.
Assuntos
Carbono , Cisteína , Epigênese Genética , Formaldeído , Metionina Adenosiltransferase , S-Adenosilmetionina , Animais , Camundongos , Carbono/metabolismo , Epigênese Genética/efeitos dos fármacos , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , S-Adenosilmetionina/antagonistas & inibidores , S-Adenosilmetionina/metabolismo , Formaldeído/metabolismo , Formaldeído/toxicidade , Exposição Ambiental , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Cisteína/metabolismo , Humanos , Células Hep G2RESUMO
Methionine adenosyltransferase 2A (MAT2A) has been indicated as a drug target for oncology indications. Clinical trials with MAT2A inhibitors are currently on-going. Here, a structure-based virtual screening campaign was performed on the commercially available chemical space which yielded two novel MAT2A-inhibitor chemical series. The binding modes of the compounds were confirmed with X-ray crystallography. Both series have acceptable physicochemical properties and show nanomolar activity in the biochemical MAT2A inhibition assay and single-digit micromolar activity in the proliferation assay (MTAP -/- cell line). The identified compounds and the relating structural data could be helpful in related drug discovery projects.
Assuntos
Bioensaio , Metionina Adenosiltransferase , Linhagem Celular , Cristalografia por Raios X , Metionina Adenosiltransferase/antagonistas & inibidores , Terapia de Alvo MolecularRESUMO
PURPOSE OF REVIEW: In this review, we summarize the biological roles of methionine, methionine adenosyl transferase 2A (MAT2A) and S -adenosyl methionine (SAM) in methylation reactions during tumorigenesis. Newly emerged inhibitors targeting the methionine-MAT2A-SAM axis will be discussed. RECENT FINDINGS: SAM is the critical and global methyl-donor for methylation reactions regulating gene expression, and in mammalian cells, it is synthesized by MAT2A using methionine. Recent studies have validated methionine and MAT2A as metabolic dependencies of cancer cells because of their essential roles in SAM biosynthesis. MAT2A inhibition leads to synthetic lethality in methylthioadenosine-phosphorylase (MTAP)-deleted cancers, which accounts for 15% of all cancer types. Of note, remarkable progress has been made in developing inhibitors targeting the methionine-MAT2A-SAM axis, as the first-in-class MAT2A inhibitors AG-270 and IDE397 enter clinical trials to treat cancer. SUMMARY: The methionine-MAT2A-SAM axis plays an important role in tumorigenesis by providing SAM as a critical substrate for abnormal protein as well as DNA and RNA methylation in cancer cells. Targeting SAM biosynthesis through MAT2A inhibition has emerged as a novel and promising strategy for cancer therapy.
Assuntos
Neoplasias , Animais , Carcinogênese , Humanos , Mamíferos/metabolismo , Metionina/metabolismo , Metionina Adenosiltransferase/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , S-Adenosilmetionina/metabolismoRESUMO
Methionine adenosyltransferase 2A (MAT2A) is a rate-limiting enzyme in the methionine cycle that primarily catalyzes the synthesis of S-adenosylmethionine (SAM) from methionine and adenosine triphosphate (ATP). MAT2A has been recognized as a therapeutic target for the treatment of cancers. Recently, a few MAT2A inhibitors have been reported, and three entered clinical trials to treat solid tumorsor lymphoma with MTAP loss. This review aims to summarize the current understanding of the roles of MAT2A in cancer and the discovery of MAT2A inhibitors. Furthermore, a perspective on the use of MAT2A inhibitors for the treatment of cancer is also discussed. We hope to provide guidance for future drug design and optimization via analysis of the binding modes of known MAT2A inhibitors.
Assuntos
Metionina Adenosiltransferase , Neoplasias , Humanos , Metionina/metabolismo , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , S-Adenosilmetionina/metabolismoRESUMO
S-Adenosylmethionine lyase (SAMase) of bacteriophage T3 degrades the intracellular SAM pools of the host Escherichia coli cells, thereby inactivating a crucial metabolite involved in a plethora of cellular functions, including DNA methylation. SAMase is the first viral protein expressed upon infection, and its activity prevents methylation of the T3 genome. Maintenance of the phage genome in a fully unmethylated state has a profound effect on the infection strategy. It allows T3 to shift from a lytic infection under normal growth conditions to a transient lysogenic infection under glucose starvation. Using single-particle cryoelectron microscopy (cryo-EM) and biochemical assays, we demonstrate that SAMase performs its function by not only degrading SAM but also by interacting with and efficiently inhibiting the host's methionine S-adenosyltransferase (MAT), the enzyme that produces SAM. Specifically, SAMase triggers open-ended head-to-tail assembly of E. coli MAT into an unusual linear filamentous structure in which adjacent MAT tetramers are joined by two SAMase dimers. Molecular dynamics simulations together with normal mode analyses suggest that the entrapment of MAT tetramers within filaments leads to an allosteric inhibition of MAT activity due to a shift to low-frequency, high-amplitude active-site-deforming modes. The amplification of uncorrelated motions between active-site residues weakens MAT's substrate binding affinity, providing a possible explanation for the observed loss of function. We propose that the dual function of SAMase as an enzyme that degrades SAM and as an inhibitor of MAT activity has emerged to achieve an efficient depletion of the intracellular SAM pools. IMPORTANCE Self-assembly of enzymes into filamentous structures in response to specific metabolic cues has recently emerged as a widespread strategy of metabolic regulation. In many instances, filamentation of metabolic enzymes occurs in response to starvation and leads to functional inactivation. Here, we report that bacteriophage T3 modulates the metabolism of the host E. coli cells by recruiting a similar strategy: silencing a central metabolic enzyme by subjecting it to phage-mediated polymerization. This observation points to an intriguing possibility that virus-induced polymerization of the host metabolic enzymes is a common mechanism implemented by viruses to metabolically reprogram and subdue infected cells.
Assuntos
Bacteriófago T3/enzimologia , Escherichia coli/enzimologia , Interações entre Hospedeiro e Microrganismos , Metionina Adenosiltransferase/antagonistas & inibidores , Polímeros/metabolismo , Proteínas Virais/metabolismo , Bacteriófago T3/genética , Microscopia Crioeletrônica , Escherichia coli/genética , Hidrolases/metabolismo , Lisogenia , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Polimerização , Polímeros/química , Proteínas Virais/genéticaRESUMO
Interplay between EBV infection and acquired genetic alterations during nasopharyngeal carcinoma (NPC) development remains vague. Here we report a comprehensive genomic analysis of 70 NPCs, combining whole-genome sequencing (WGS) of microdissected tumor cells with EBV oncogene expression to reveal multiple aspects of cellular-viral co-operation in tumorigenesis. Genomic aberrations along with EBV-encoded LMP1 expression underpin constitutive NF-κB activation in 90% of NPCs. A similar spectrum of somatic aberrations and viral gene expression undermine innate immunity in 79% of cases and adaptive immunity in 47% of cases; mechanisms by which NPC may evade immune surveillance despite its pro-inflammatory phenotype. Additionally, genomic changes impairing TGFBR2 promote oncogenesis and stabilize EBV infection in tumor cells. Fine-mapping of CDKN2A/CDKN2B deletion breakpoints reveals homozygous MTAP deletions in 32-34% of NPCs that confer marked sensitivity to MAT2A inhibition. Our work concludes that NPC is a homogeneously NF-κB-driven and immune-protected, yet potentially druggable, cancer.
Assuntos
Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4/genética , Carcinoma Nasofaríngeo/imunologia , Neoplasias Nasofaríngeas/imunologia , Evasão Tumoral/genética , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Carcinogênese/imunologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/terapia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Regulação Viral da Expressão Gênica/imunologia , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/patogenicidade , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/metabolismo , Camundongos , NF-kappa B/metabolismo , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/terapia , Carcinoma Nasofaríngeo/virologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/terapia , Neoplasias Nasofaríngeas/virologia , Nasofaringe/imunologia , Nasofaringe/patologia , Nasofaringe/cirurgia , Nasofaringe/virologia , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptor do Fator de Crescimento Transformador beta Tipo II/metabolismo , Deleção de Sequência , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Evasão Tumoral/efeitos dos fármacos , Sequenciamento Completo do Genoma , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
MAT2a is a methionine adenosyltransferase that synthesizes the essential metabolite S-adenosylmethionine (SAM) from methionine and ATP. Tumors bearing the co-deletion of p16 and MTAP genes have been shown to be sensitive to MAT2a inhibition, making it an attractive target for treatment of MTAP-deleted cancers. A fragment-based lead generation campaign identified weak but efficient hits binding in a known allosteric site. By use of structure-guided design and systematic SAR exploration, the hits were elaborated through a merging and growing strategy into an arylquinazolinone series of potent MAT2a inhibitors. The selected in vivo tool compound 28 reduced SAM-dependent methylation events in cells and inhibited proliferation of MTAP-null cells in vitro. In vivo studies showed that 28 was able to induce antitumor response in an MTAP knockout HCT116 xenograft model.
Assuntos
Desenho de Fármacos , Inibidores Enzimáticos/química , Metionina Adenosiltransferase/antagonistas & inibidores , Sítio Alostérico , Animais , Proliferação de Células , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Técnicas de Inativação de Genes , Células HCT116 , Meia-Vida , Humanos , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Camundongos , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Quinazolinas/química , Quinazolinas/metabolismo , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Ratos , S-Adenosilmetionina/metabolismo , Relação Estrutura-Atividade , Transplante HeterólogoRESUMO
The metabolic enzyme methionine adenosyltransferase 2A (MAT2A) was recently implicated as a synthetic lethal target in cancers with deletion of the methylthioadenosine phosphorylase (MTAP) gene, which is adjacent to the CDKN2A tumor suppressor and codeleted with CDKN2A in approximately 15% of all cancers. Previous attempts to target MAT2A with small-molecule inhibitors identified cellular adaptations that blunted their efficacy. Here, we report the discovery of highly potent, selective, orally bioavailable MAT2A inhibitors that overcome these challenges. Fragment screening followed by iterative structure-guided design enabled >10â¯000-fold improvement in potency of a family of allosteric MAT2A inhibitors that are substrate noncompetitive and inhibit release of the product, S-adenosyl methionine (SAM), from the enzyme's active site. We demonstrate that potent MAT2A inhibitors substantially reduce SAM levels in cancer cells and selectively block proliferation of MTAP-null cells both in tissue culture and xenograft tumors. These data supported progressing AG-270 into current clinical studies (ClinicalTrials.gov NCT03435250).
Assuntos
Inibidores Enzimáticos/química , Metionina Adenosiltransferase/antagonistas & inibidores , Purina-Núcleosídeo Fosforilase/genética , Sítios de Ligação , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Homozigoto , Humanos , Metionina Adenosiltransferase/metabolismo , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Purina-Núcleosídeo Fosforilase/metabolismo , S-Adenosilmetionina/metabolismo , Relação Estrutura-AtividadeRESUMO
S-Adenosyl-l-methionine (AdoMet) is synthesized by the MAT2A isozyme of methionine adenosyltransferase in most human tissues and in cancers. Its contribution to epigenetic control has made it a target for anticancer intervention. A recent kinetic isotope effect analysis of MAT2A demonstrated a loose nucleophilic transition state. Here we show that MAT2A has a sequential mechanism with a rate-limiting step of formation of AdoMet, followed by rapid hydrolysis of the ß-γ bond of triphosphate, and rapid release of phosphate and pyrophosphate. MAT2A catalyzes the slow hydrolysis of both ATP and triphosphate in the absence of other reactants. Positional isotope exchange occurs with 18O as the 5'-oxygen of ATP. Loss of the triphosphate is sufficiently reversible to permit rotation and recombination of the α-phosphoryl group of ATP. Adenosine (α-ß or ß-γ)-imido triphosphates are slow substrates, and the respective imido triphosphates are inhibitors. The hydrolytically stable (α-ß, ß-γ)-diimido triphosphate (PNPNP) is a nanomolar inhibitor. The MAT2A protein structure is highly stabilized against denaturation by binding of PNPNP. A crystal structure of MAT2A with 5'-methylthioadenosine and PNPNP shows the ligands arranged appropriately in the ATP binding site. Two magnesium ions chelate the α- and γ-phosphoryl groups of PNPNP. The ß-phosphoryl oxygen is in contact with an essential potassium ion. Imidophosphate derivatives provide contact models for the design of catalytic site ligands for MAT2A.
Assuntos
Trifosfato de Adenosina/metabolismo , Difosfatos/metabolismo , Inibidores Enzimáticos/farmacologia , Metionina Adenosiltransferase/antagonistas & inibidores , Metionina Adenosiltransferase/metabolismo , Polifosfatos/metabolismo , S-Adenosilmetionina/farmacologia , Sítios de Ligação , Humanos , Hidrólise , Cinética , Conformação ProteicaRESUMO
The methylthioadenosine phosphorylase (MTAP) gene is located adjacent to the cyclin-dependent kinase inhibitor 2A (CDKN2A) tumor-suppressor gene and is co-deleted with CDKN2A in approximately 15% of all cancers. This co-deletion leads to aggressive tumors with poor prognosis that lack effective, molecularly targeted therapies. The metabolic enzyme methionine adenosyltransferase 2α (MAT2A) was identified as a synthetic lethal target in MTAP-deleted cancers. We report the characterization of potent MAT2A inhibitors that substantially reduce levels of S-adenosylmethionine (SAM) and demonstrate antiproliferative activity in MTAP-deleted cancer cells and tumors. Using RNA sequencing and proteomics, we demonstrate that MAT2A inhibition is mechanistically linked to reduced protein arginine methyltransferase 5 (PRMT5) activity and splicing perturbations. We further show that DNA damage and mitotic defects ensue upon MAT2A inhibition in HCT116 MTAP-/- cells, providing a rationale for combining the MAT2A clinical candidate AG-270 with antimitotic taxanes.
Assuntos
Dano ao DNA/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Metionina Adenosiltransferase/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/genética , Purina-Núcleosídeo Fosforilase/genética , Splicing de RNA/efeitos dos fármacos , RNA Mensageiro/genética , Animais , Linhagem Celular , Linhagem Celular Tumoral , Inibidor p16 de Quinase Dependente de Ciclina , Dano ao DNA/genética , Deleção de Genes , Células HCT116 , Células HEK293 , Humanos , Metionina Adenosiltransferase/genética , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Neoplasias/tratamento farmacológico , Neoplasias/genética , Splicing de RNA/genética , S-Adenosilmetionina/metabolismoRESUMO
The active polyphenol curcumin demonstrates therapeutic effects against various different diseases. Researches revealed the inhibitory roles of curcumin in hepatic stellate cell (HSC) activation and fibrogenesis. HSC activation, a key step in liver fibrogenesis, requires the remodeling of DNA methylation, which is associated with methionine adenosyltransferase II (MATII) composed of catalytic subunit MAT2A and regulatory subunit MAT2B. MATII is essential for HSC activation in vitro. The present researches aimed to investigate the effect of curcumin on MAT2B expression in HSCs in vivo and in vitro. Results demonstrated that curcumin could reduce MAT2B expression in HSCs at multiple levels. The activation of p38 MAPK pathway promoted MAT2B expression in HSCs. The effect of curcumin on MAT2B was through its interruption of p38 MAPK signaling pathway. Knockdown of MAT2B inhibited HSC activation and reduced collagen level in the model of liver fibrosis. Curcumin down-regulation of MAT2B contributed to the inhibitory role of curcumin on HSC activation and collagen expression in mouse livers. This study provided evidences for the effect of curcumin on the expression of MAT2B, an enzyme for the biosynthesis of methyl donor S-adenosylmethionine, in HSCs and demonstrated the function significance of curcumin-induced downregulation of MAT2B in curcumin inhibition of liver fibrosis.
Assuntos
Curcumina/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/enzimologia , Metionina Adenosiltransferase/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos , Animais , Colágeno/metabolismo , Regulação para Baixo/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Cirrose Hepática/patologia , Cirrose Hepática/prevenção & controle , Masculino , Metionina Adenosiltransferase/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , S-Adenosilmetionina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
BACKGROUND: It is prudent that novel classes of antibiotics be urgently developed to manage the WHO prioritized multi-drug resistant (MDR) pathogens posing an unprecedented medical crisis. Simultaneously, multiple essential proteins have to be targeted to prevent easy resistance development. METHODS: An integration of structure-based virtual screening and ligand-based virtual screening was employed to explore the antimicrobial properties of indole derivatives from a compound database. RESULTS: Whole-genome sequences of the target pathogens were aligned exploiting DNA alignment potential of MAUVE to identify putative common lead target proteins. S-adenosyl methionine (SAM) biosynthesizing MetK was taken as the lead target and various literature searches revealed that SAM is a critical metabolite. Furthermore, SAM utilizing CobA involved in the B12 biosynthesis pathway, Dam in the regulation of replication and protein expression, and TrmD in methylation of tRNA were also taken as drug targets. The ligand library of 715 indole derivatives chosen based on kinase inhibition potential of indoles was created from which 102 were pursued based on ADME/T scores. Among these, 5 potential inhibitors of MetK in N. gonorrhoeae were further expanded to molecular docking studies in MetK proteins of all nine pathogens among which 3 derivatives exhibited inhibition potential. These 3 upon docking in other SAM utilizing enzymes, CobA, Dam, and TrmD gave 2 potential compounds with multiple targets. Further, docking with human MetK homolog also showed probable inhibitory effects however SAM requirements can be replenished from external sources since SAM transporters are present in humans. CONCLUSIONS: We believe these molecules 3-[(4-hydroxyphenyl)methyl]-6-(1H-indol-3-ylmethyl)piperazine-2,5-dione (ZINC04899565) and 1-[(3S)-3-[5-(1H-indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyrrolidin-1-yl]ethanone (ZINC49171024) could be a starting point to help develop broad-spectrum antibiotics against infections caused by N. gonorrhoeae, A. baumannii, C. coli, K. pneumoniae, E. faecium, H. pylori, P. aeruginosa, S. aureus and S. typhi.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Indóis/farmacologia , Metionina Adenosiltransferase/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Antibacterianos/química , Antibacterianos/toxicidade , Bactérias/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana , Indóis/química , Indóis/toxicidade , Ligantes , Metionina Adenosiltransferase/metabolismo , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/toxicidade , S-Adenosilmetionina/metabolismoRESUMO
BACKGROUND: Chronic Myeloid Leukaemia (CML) starts in certain blood-forming cells of the bone marrow when cells acquire Philadelphia chromosome. Nowadays, scientists attempt to find novel and safe therapeutic agents and approaches for CML therapy using Tyrosine Kinase Inhibitors (TKIs), CML conventional treatment agents, has some restrictions and also adverse effects. Recently, it has been proposed that phytochemicals, such as flavonoids due to their low side effects and notable safety have the potential to be used for CML therapy. MATERIALS AND METHODS: K-562 cells were exposed with three concentrations of the querectin (10, 40 and 80µM) for 12, 24 and 48 hours. After that, these cells apoptosis rate was estimated using Annexin-V/PI staining and flowcytometry analysis, and their proliferation rate was evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT). Finally, the expression of the 70 and 90 kilodalton heat shock proteins (HSP70 and 90), methionine adenosyltransferase 2A (MAT2A), Forkhead box protein M1 (FOXM1), caspase-3 and -8, Bcl-X(L) and Bax involved in leukemic cells survival and proliferation was assessed using Real-Time PCR within 12, 24 and 48 hours after exposure with quercetin 40 and 80µM. RESULTS: Considering consequences, querecetin induced apoptosis in K-562 cells, and also abrogated these cells proliferation. On the other hand, RT-PCR results showed a reduction in some of the candidate genes expression, especially HSP70, Bcl-X(L) and FOXM1, when cells were treated with quercetin 40 and 80µM. Also, Bax, caspase-3 and caspase-8 expression was significantly improved in K-562 cells upon quercetin exposure. CONCLUSION: We concluded that CML therapy by querecetin due to its anti-proliferative and anti-survival potentials could lead to the promising therapeutic outcome through targeting major survival and proliferation involved genes expression.
Assuntos
Antineoplásicos/farmacologia , Proteína Forkhead Box M1/antagonistas & inibidores , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Metionina Adenosiltransferase/antagonistas & inibidores , Quercetina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Estrutura Molecular , Quercetina/síntese química , Quercetina/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Understanding cellular metabolism holds immense potential for developing new classes of therapeutics that target metabolic pathways in cancer. Metabolic pathways are altered in bulk neoplastic cells in comparison to normal tissues. However, carcinoma cells within tumors are heterogeneous, and tumor-initiating cells (TICs) are important therapeutic targets that have remained metabolically uncharacterized. To understand their metabolic alterations, we performed metabolomics and metabolite tracing analyses, which revealed that TICs have highly elevated methionine cycle activity and transmethylation rates that are driven by MAT2A. High methionine cycle activity causes methionine consumption to far outstrip its regeneration, leading to addiction to exogenous methionine. Pharmacological inhibition of the methionine cycle, even transiently, is sufficient to cripple the tumor-initiating capability of these cells. Methionine cycle flux specifically influences the epigenetic state of cancer cells and drives tumor initiation. Methionine cycle enzymes are also enriched in other tumor types, and MAT2A expression impinges upon the sensitivity of certain cancer cells to therapeutic inhibition.