RESUMO
Selpercatinib is a small molecule that binds at the RET kinase active site. It inhibits activity of constitutively dimerized RET fusion proteins and activated point mutants, thereby blocking downstream signals for proliferation and survival. It is the first selective RET inhibitor to be FDA approved for tumor agnostic targeting of oncogenic RET fusion proteins. To view this Bench to Bedside, open or download the PDF.
Assuntos
Neoplasias , Inibidores de Proteínas Quinases , Proteínas Proto-Oncogênicas c-ret , Humanos , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-ret/antagonistas & inibidores , Piridinas , Aprovação de DrogasRESUMO
TRIKAFTA is the third drug approved by the FDA that rescues defects caused by the major mutation F508del. It is superior to its predecessors that were approved for patients who are homozygous for F508del because TRIKAFTA is also effective in CF patients who harbor only one copy of this mutation.
Assuntos
Aminofenóis/farmacologia , Benzodioxóis/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/tratamento farmacológico , Indóis/farmacologia , Pirazóis/farmacologia , Piridinas/farmacologia , Quinolinas/farmacologia , Combinação de Medicamentos , Heterozigoto , Humanos , MutaçãoRESUMO
Transcription of viral mRNA in cells infected with influenza viruses involves capturing and cleaving the first 10-20 nucleotides of 5' capped host mRNAs to be used as primers in viral RNA synthesis. A newly developed inhibitor of the viral endonuclease responsible for this cap-snatching shows therapeutic efficacy for the treatment of influenza. To view this Bench to Bedside, open or download the PDF.
Assuntos
Influenza Humana/tratamento farmacológico , Oxazinas/farmacologia , Oxazinas/uso terapêutico , Piridinas/farmacologia , Piridinas/uso terapêutico , Tiepinas/farmacologia , Tiepinas/uso terapêutico , Triazinas/farmacologia , Triazinas/uso terapêutico , Dibenzotiepinas , Endonucleases/genética , Humanos , Morfolinas , Orthomyxoviridae/efeitos dos fármacos , Orthomyxoviridae/patogenicidade , Piridonas , Capuzes de RNA/genética , RNA Mensageiro/genética , RNA Viral/genética , Proteínas Virais/genéticaRESUMO
Nearly all prostate cancer deaths are from metastatic castration-resistant prostate cancer (mCRPC), but there have been few whole-genome sequencing (WGS) studies of this disease state. We performed linked-read WGS on 23 mCRPC biopsy specimens and analyzed cell-free DNA sequencing data from 86 patients with mCRPC. In addition to frequent rearrangements affecting known prostate cancer genes, we observed complex rearrangements of the AR locus in most cases. Unexpectedly, these rearrangements include highly recurrent tandem duplications involving an upstream enhancer of AR in 70%-87% of cases compared with <2% of primary prostate cancers. A subset of cases displayed AR or MYC enhancer duplication in the context of a genome-wide tandem duplicator phenotype associated with CDK12 inactivation. Our findings highlight the complex genomic structure of mCRPC, nominate alterations that may inform prostate cancer treatment, and suggest that additional recurrent events in the non-coding mCRPC genome remain to be discovered.
Assuntos
Neoplasias de Próstata Resistentes à Castração/patologia , Receptores Androgênicos/genética , Sequenciamento Completo do Genoma , Idoso , Anilidas/uso terapêutico , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Elementos Facilitadores Genéticos/genética , Duplicação Gênica , Rearranjo Gênico , Genes myc , Loci Gênicos , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , PTEN Fosfo-Hidrolase/genética , Fenótipo , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêuticoRESUMO
The hedgehog (Hh) signaling pathway is aberrantly activated in a majority of basal cell carcinomas (BCC). Vismodegib and sonidegib are targeted inhibitors of Smoothened (SMO). Both drugs are approved for use in locally advanced BCC (laBCC), with vismodegib also approved for metastatic BCC (mBCC).
Assuntos
Anilidas/uso terapêutico , Antineoplásicos/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Carcinoma Basocelular/tratamento farmacológico , Proteínas Hedgehog/metabolismo , Piridinas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/tratamento farmacológico , Humanos , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptor Smoothened , Pesquisa Translacional BiomédicaRESUMO
Bedaquiline (BDQ), a first-in-class diarylquinoline anti-tuberculosis drug, and its analogue, TBAJ-587, prevent the growth and proliferation of Mycobacterium tuberculosis by inhibiting ATP synthase1,2. However, BDQ also inhibits human ATP synthase3. At present, how these compounds interact with either M. tuberculosis ATP synthase or human ATP synthase is unclear. Here we present cryogenic electron microscopy structures of M. tuberculosis ATP synthase with and without BDQ and TBAJ-587 bound, and human ATP synthase bound to BDQ. The two inhibitors interact with subunit a and the c-ring at the leading site, c-only sites and lagging site in M. tuberculosis ATP synthase, showing that BDQ and TBAJ-587 have similar modes of action. The quinolinyl and dimethylamino units of the compounds make extensive contacts with the protein. The structure of human ATP synthase in complex with BDQ reveals that the BDQ-binding site is similar to that observed for the leading site in M. tuberculosis ATP synthase, and that the quinolinyl unit also interacts extensively with the human enzyme. This study will improve researchers' understanding of the similarities and differences between human ATP synthase and M. tuberculosis ATP synthase in terms of the mode of BDQ binding, and will allow the rational design of novel diarylquinolines as anti-tuberculosis drugs.
Assuntos
Antituberculosos , Diarilquinolinas , Imidazóis , ATPases Mitocondriais Próton-Translocadoras , Mycobacterium tuberculosis , Piperidinas , Piridinas , Humanos , Antituberculosos/farmacologia , Antituberculosos/química , Sítios de Ligação , Microscopia Crioeletrônica , Diarilquinolinas/química , Diarilquinolinas/farmacologia , Imidazóis/química , Imidazóis/farmacologia , ATPases Mitocondriais Próton-Translocadoras/antagonistas & inibidores , ATPases Mitocondriais Próton-Translocadoras/química , ATPases Mitocondriais Próton-Translocadoras/metabolismo , ATPases Mitocondriais Próton-Translocadoras/ultraestrutura , Modelos Moleculares , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/efeitos dos fármacos , Piperidinas/química , Piperidinas/farmacologia , Subunidades Proteicas/metabolismo , Subunidades Proteicas/química , Subunidades Proteicas/antagonistas & inibidores , Piridinas/química , Piridinas/farmacologiaRESUMO
Pyridines and related N-heteroarenes are commonly found in pharmaceuticals, agrochemicals and other biologically active compounds1,2. Site-selective C-H functionalization would provide a direct way of making these medicinally active products3-5. For example, nicotinic acid derivatives could be made by C-H carboxylation, but this remains an elusive transformation6-8. Here we describe the development of an electrochemical strategy for the direct carboxylation of pyridines using CO2. The choice of the electrolysis setup gives rise to divergent site selectivity: a divided electrochemical cell leads to C5 carboxylation, whereas an undivided cell promotes C4 carboxylation. The undivided-cell reaction is proposed to operate through a paired-electrolysis mechanism9,10, in which both cathodic and anodic events play critical roles in altering the site selectivity. Specifically, anodically generated iodine preferentially reacts with a key radical anion intermediate in the C4-carboxylation pathway through hydrogen-atom transfer, thus diverting the reaction selectivity by means of the Curtin-Hammett principle11. The scope of the transformation was expanded to a wide range of N-heteroarenes, including bipyridines and terpyridines, pyrimidines, pyrazines and quinolines.
Assuntos
Dióxido de Carbono , Eletroquímica , Pirazinas , Piridinas , Pirimidinas , Quinolinas , Hidrogênio/química , Pirazinas/química , Piridinas/química , Pirimidinas/química , Eletroquímica/métodos , Dióxido de Carbono/química , Quinolinas/química , Preparações Farmacêuticas/síntese química , Preparações Farmacêuticas/químicaRESUMO
Among the five KCNQ channels, also known as the Kv7 voltage-gated potassium (Kv) channels, KCNQ2-KCNQ5 control neuronal excitability. Dysfunctions of KCNQ2-KCNQ5 are associated with neurological disorders such as epilepsy, deafness, and neuropathic pain. Here, we report the cryoelectron microscopy (cryo-EM) structures of human KCNQ4 and its complexes with the opener retigabine or the blocker linopirdine at overall resolutions of 2.5, 3.1, and 3.3 Å, respectively. In all structures, a phosphatidylinositol 4,5-bisphosphate (PIP2) molecule inserts its head group into a cavity within each voltage-sensing domain (VSD), revealing an unobserved binding mode for PIP2. Retigabine nestles in each fenestration, inducing local shifts. Instead of staying within the central pore, linopirdine resides in a cytosolic cavity underneath the inner gate. Electrophysiological analyses of various mutants corroborated the structural observations. Our studies reveal the molecular basis for the modulatory mechanism of neuronal KCNQ channels and provide a framework for structure-facilitated drug discovery targeting these important channels.
Assuntos
Carbamatos/farmacologia , Indóis/farmacologia , Canais de Potássio KCNQ , Fenilenodiaminas/farmacologia , Piridinas/farmacologia , Animais , Microscopia Crioeletrônica , Humanos , Canais de Potássio KCNQ/agonistas , Canais de Potássio KCNQ/antagonistas & inibidores , Canais de Potássio KCNQ/genética , Canais de Potássio KCNQ/metabolismo , Mutação , Fosfatidilinositol 4,5-Difosfato/metabolismo , Domínios Proteicos , Células Sf9 , SpodopteraRESUMO
Ferroptosis is a form of necrotic cell death caused by iron-dependent peroxidation of polyunsaturated phospholipids on cell membranes and is actively suppressed by the cellular antioxidant systems. We report here that oxidoreductases, including NADPH-cytochrome P450 reductase (POR) and NADH-cytochrome b5 reductase (CYB5R1), transfer electrons from NAD(P)H to oxygen to generate hydrogen peroxide, which subsequently reacts with iron to generate reactive hydroxyl radicals for the peroxidation of the polyunsaturated fatty acid (PUFA) chains of membrane phospholipids, thereby disrupting membrane integrity during ferroptosis. Genetic knockout of POR and CYB5R1 decreases cellular hydrogen peroxide generation, preventing lipid peroxidation and ferroptosis. Moreover, POR knockdown in mouse liver prevents ConA-induced liver damage. Ferroptosis, therefore, is a result of incidental electron transfer carried out by POR/CYB5R1 oxidoreductase and thus needs to be constitutively countered by the antioxidant systems.
Assuntos
Membrana Celular/química , Sistema Enzimático do Citocromo P-450/genética , Citocromo-B(5) Redutase/genética , Ácidos Graxos Insaturados/metabolismo , Ferroptose/genética , NADP/metabolismo , Animais , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Concanavalina A/farmacologia , Sistema Enzimático do Citocromo P-450/deficiência , Citocromo-B(5) Redutase/deficiência , Transporte de Elétrons/efeitos dos fármacos , Ferroptose/efeitos dos fármacos , Células HEK293 , Células HeLa , Humanos , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Oxigênio/metabolismo , Compostos de Fenilureia/farmacologia , Piperazinas/farmacologia , Piridinas/farmacologia , Sorafenibe/farmacologiaRESUMO
Cells have evolved an elaborate DNA repair network to ensure complete and accurate DNA replication. Defects in these repair machineries can fuel genome instability and drive carcinogenesis while creating vulnerabilities that may be exploited in therapy. Here, we use nascent chromatin capture (NCC) proteomics to characterize the repair of replication-associated DNA double-strand breaks (DSBs) triggered by topoisomerase 1 (TOP1) inhibitors. We reveal profound changes in the fork proteome, including the chromatin environment and nuclear membrane interactions, and identify three classes of repair factors according to their enrichment at broken and/or stalled forks. ATM inhibition dramatically rewired the broken fork proteome, revealing that ataxia telangiectasia mutated (ATM) signalling stimulates DNA end resection, recruits PLK1, and concomitantly suppresses the canonical DSB ubiquitination response by preventing accumulation of RNF168 and BRCA1-A. This work and collection of replication fork proteomes provide a new framework to understand how cells orchestrate homologous recombination repair of replication-associated DSBs.
Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas de Ciclo Celular/genética , Replicação do DNA , DNA Topoisomerases Tipo I/genética , DNA/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Reparo de DNA por Recombinação , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Camptotecina/farmacologia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Cromatina/química , Cromatina/metabolismo , DNA/metabolismo , Quebras de DNA de Cadeia Dupla , DNA Topoisomerases Tipo I/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Regulação da Expressão Gênica , Células HeLa , Humanos , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Proteômica/métodos , Proteínas Proto-Oncogênicas/metabolismo , Piridinas/farmacologia , Quinolinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Inibidores da Topoisomerase I/farmacologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/efeitos dos fármacos , Quinase 1 Polo-LikeRESUMO
Ingestion of alkaloid metabolites from the bark of Galbulimima (GB) sp. leads to psychotropic and excitatory effects in humans1-4. Limited, variable supply of GB alkaloids5, however, has impeded their biological exploration and clinical development6. Here we report a solution to the supply of GB18, a structural outlier and putative psychotropic principle of Galbulimima bark. Efficient access to its challenging tetrahedral attached-ring motif required the development of a ligand-controlled endo-selective cross-electrophile coupling and a diastereoselective hydrogenation of a rotationally dynamic pyridine. Reliable, gram-scale access to GB18 enabled its assignment as a potent antagonist of κ- and µ-opioid receptors-the first new targets in 35 years-and lays the foundation to navigate and understand the biological activity of Galbulimima metabolites.
Assuntos
Alcaloides , Magnoliopsida , Alcaloides/síntese química , Alcaloides/farmacologia , Técnicas de Química Sintética , Humanos , Hidrogenação , Ligantes , Magnoliopsida/química , Casca de Planta/química , Piridinas , Receptores Opioides kappa/antagonistas & inibidores , Receptores Opioides mu/antagonistas & inibidoresRESUMO
Wnt signalling is essential for regulation of embryonic development and adult tissue homeostasis1-3, and aberrant Wnt signalling is frequently associated with cancers4. Wnt signalling requires palmitoleoylation on a hairpin 2 motif by the endoplasmic reticulum-resident membrane-bound O-acyltransferase Porcupine5-7 (PORCN). This modification is indispensable for Wnt binding to its receptor Frizzled, which triggers signalling8,9. Here we report four cryo-electron microscopy structures of human PORCN: the complex with the palmitoleoyl-coenzyme A (palmitoleoyl-CoA) substrate; the complex with the PORCN inhibitor LGK974, an anti-cancer drug currently in clinical trials10; the complex with LGK974 and WNT3A hairpin 2 (WNT3Ap); and the complex with a synthetic palmitoleoylated WNT3Ap analogue. The structures reveal that hairpin 2 of WNT3A, which is well conserved in all Wnt ligands, inserts into PORCN from the lumenal side, and the palmitoleoyl-CoA accesses the enzyme from the cytosolic side. The catalytic histidine triggers the transfer of the unsaturated palmitoleoyl group to the target serine on the Wnt hairpin 2, facilitated by the proximity of the two substrates. The inhibitor-bound structure shows that LGK974 occupies the palmitoleoyl-CoA binding site to prevent the reaction. Thus, this work provides a mechanism for Wnt acylation and advances the development of PORCN inhibitors for cancer treatment.
Assuntos
Aciltransferases , Proteínas de Membrana , Via de Sinalização Wnt , Acilação/efeitos dos fármacos , Aciltransferases/antagonistas & inibidores , Aciltransferases/metabolismo , Antineoplásicos , Sítios de Ligação , Coenzima A/metabolismo , Microscopia Crioeletrônica , Histidina , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Palmitoil Coenzima A , Pirazinas/farmacologia , Piridinas/farmacologia , Serina , Especificidade por Substrato , Via de Sinalização Wnt/efeitos dos fármacos , Proteína Wnt3ARESUMO
KRAS gain-of-function mutations are frequently observed in sporadic arteriovenous malformations. The mechanisms underlying the progression of such KRAS-driven malformations are still incompletely understood, and no treatments for the condition are approved. Here, we show the effectiveness of sotorasib, a specific KRAS G12C inhibitor, in reducing the volume of vascular malformations and improving survival in two mouse models carrying a mosaic Kras G12C mutation. We then administered sotorasib to two adult patients with severe KRAS G12C-related arteriovenous malformations. Both patients had rapid reductions in symptoms and arteriovenous malformation size. Targeting KRAS G12C appears to be a promising therapeutic approach for patients with KRAS G12C-related vascular malformations. (Funded by the European Research Council and others.).
Assuntos
Malformações Arteriovenosas , Proteínas Proto-Oncogênicas p21(ras) , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/diagnóstico por imagem , Malformações Arteriovenosas/tratamento farmacológico , Malformações Arteriovenosas/genética , Modelos Animais de Doenças , Mutação com Ganho de Função , Mutação , Piperazinas/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras)/genética , Piridinas/uso terapêutico , Pirimidinas , Fármacos Cardiovasculares/uso terapêutico , Adulto JovemRESUMO
In lymph nodes, fibroblastic reticular cells (FRCs) form a collagen-based reticular network that supports migratory dendritic cells (DCs) and T cells and transports lymph. A hallmark of FRCs is their propensity to contract collagen, yet this function is poorly understood. Here we demonstrate that podoplanin (PDPN) regulates actomyosin contractility in FRCs. Under resting conditions, when FRCs are unlikely to encounter mature DCs expressing the PDPN receptor CLEC-2, PDPN endowed FRCs with contractile function and exerted tension within the reticulum. Upon inflammation, CLEC-2 on mature DCs potently attenuated PDPN-mediated contractility, which resulted in FRC relaxation and reduced tissue stiffness. Disrupting PDPN function altered the homeostasis and spacing of FRCs and T cells, which resulted in an expanded reticular network and enhanced immunity.
Assuntos
Colágeno/metabolismo , Fibroblastos/citologia , Lectinas Tipo C/metabolismo , Linfonodos/citologia , Glicoproteínas de Membrana/metabolismo , Amidas/farmacologia , Animais , Sobrevivência Celular/imunologia , Colágeno/imunologia , Citoesqueleto/imunologia , Citoesqueleto/ultraestrutura , Inibidores Enzimáticos/farmacologia , Feminino , Fibroblastos/imunologia , Fibroblastos/ultraestrutura , Lectinas Tipo C/imunologia , Linfonodos/imunologia , Linfonodos/ultraestrutura , Masculino , Glicoproteínas de Membrana/imunologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Fosforilação , Piridinas/farmacologia , Organismos Livres de Patógenos EspecíficosRESUMO
The triumph of personalized cancer therapeutics in recent years is prompting some oncologists to rethink clinical trial design; other researchers have different priorities for trial reform.
Assuntos
Ensaios Clínicos como Assunto , Neoplasias/tratamento farmacológico , Medicina de Precisão , Crizotinibe , Estudo de Associação Genômica Ampla , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Pirazóis/uso terapêutico , Piridinas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Kinase inhibitors have limited success in cancer treatment because tumors circumvent their action. Using a quantitative proteomics approach, we assessed kinome activity in response to MEK inhibition in triple-negative breast cancer (TNBC) cells and genetically engineered mice (GEMMs). MEK inhibition caused acute ERK activity loss, resulting in rapid c-Myc degradation that induced expression and activation of several receptor tyrosine kinases (RTKs). RNAi knockdown of ERK or c-Myc mimicked RTK induction by MEK inhibitors, and prevention of proteasomal c-Myc degradation blocked kinome reprogramming. MEK inhibitor-induced RTK stimulation overcame MEK2 inhibition, but not MEK1 inhibition, reactivating ERK and producing drug resistance. The C3Tag GEMM for TNBC similarly induced RTKs in response to MEK inhibition. The inhibitor-induced RTK profile suggested a kinase inhibitor combination therapy that produced GEMM tumor apoptosis and regression where single agents were ineffective. This approach defines mechanisms of drug resistance, allowing rational design of combination therapies for cancer.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos , MAP Quinase Quinase 1/antagonistas & inibidores , Proteínas Quinases/genética , Proteoma/análise , Animais , Antineoplásicos/uso terapêutico , Benzenossulfonatos/uso terapêutico , Benzimidazóis/uso terapêutico , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Niacinamida/análogos & derivados , Compostos de Fenilureia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Piridinas/uso terapêutico , Receptores Proteína Tirosina Quinases/genética , SorafenibeRESUMO
Fluoroalkyl groups profoundly affect the physical properties of pharmaceuticals and influence almost all metrics associated with their pharmacokinetic and pharmacodynamic profile1-4. Drug candidates increasingly contain trifluoromethyl (CF3) and difluoromethyl (CF2H) groups, and the same trend in agrochemical development shows that the effect of fluoroalkylation translates across human, insect and plant life5,6. New fluoroalkylation reactions have undoubtedly stimulated this shift; however, methods that directly convert C-H bonds into C-CF2X groups (where X is F or H) in complex drug-like molecules are rare7-13. Pyridines are the most common aromatic heterocycles in pharmaceuticals14, but only one approach-via fluoroalkyl radicals-is viable for achieving pyridyl C-H fluoroalkylation in the elaborate structures encountered during drug development15-17. Here we develop a set of bench-stable fluoroalkylphosphines that directly convert the C-H bonds in pyridine building blocks, drug-like fragments and pharmaceuticals into fluoroalkyl derivatives. No preinstalled functional groups or directing groups are required. The reaction tolerates a variety of sterically and electronically distinct pyridines, and is exclusively selective for the 4-position in most cases. The reaction proceeds through initial formation of phosphonium salts followed by sp2-sp3 coupling of phosphorus ligands-an underdeveloped manifold for forming C-C bonds.
Assuntos
Carbono/química , Flúor/química , Hidrogênio/química , Fósforo/química , Piridinas/química , Alquilação , Animais , Humanos , Ligantes , Preparações Farmacêuticas/química , Farmacocinética , Fosfinas/químicaRESUMO
The initiation of cell division integrates a large number of intra- and extracellular inputs. D-type cyclins (hereafter, cyclin D) couple these inputs to the initiation of DNA replication1. Increased levels of cyclin D promote cell division by activating cyclin-dependent kinases 4 and 6 (hereafter, CDK4/6), which in turn phosphorylate and inactivate the retinoblastoma tumour suppressor. Accordingly, increased levels and activity of cyclin D-CDK4/6 complexes are strongly linked to unchecked cell proliferation and cancer2,3. However, the mechanisms that regulate levels of cyclin D are incompletely understood4,5. Here we show that autophagy and beclin 1 regulator 1 (AMBRA1) is the main regulator of the degradation of cyclin D. We identified AMBRA1 in a genome-wide screen to investigate the genetic basis of the response to CDK4/6 inhibition. Loss of AMBRA1 results in high levels of cyclin D in cells and in mice, which promotes proliferation and decreases sensitivity to CDK4/6 inhibition. Mechanistically, AMBRA1 mediates ubiquitylation and proteasomal degradation of cyclin D as a substrate receptor for the cullin 4 E3 ligase complex. Loss of AMBRA1 enhances the growth of lung adenocarcinoma in a mouse model, and low levels of AMBRA1 correlate with worse survival in patients with lung adenocarcinoma. Thus, AMBRA1 regulates cellular levels of cyclin D, and contributes to cancer development and the response of cancer cells to CDK4/6 inhibitors.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Ciclina D/metabolismo , Adenocarcinoma de Pulmão/genética , Animais , Divisão Celular , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/metabolismo , Genes Supressores de Tumor , Humanos , Neoplasias Pulmonares/genética , Camundongos , Piperazinas/farmacologia , Piridinas/farmacologia , Células U937 , UbiquitinaçãoRESUMO
Inactive state-selective KRAS(G12C) inhibitors1-8 demonstrate a 30-40% response rate and result in approximately 6-month median progression-free survival in patients with lung cancer9. The genetic basis for resistance to these first-in-class mutant GTPase inhibitors remains under investigation. Here we evaluated matched pre-treatment and post-treatment specimens from 43 patients treated with the KRAS(G12C) inhibitor sotorasib. Multiple treatment-emergent alterations were observed across 27 patients, including alterations in KRAS, NRAS, BRAF, EGFR, FGFR2, MYC and other genes. In preclinical patient-derived xenograft and cell line models, resistance to KRAS(G12C) inhibition was associated with low allele frequency hotspot mutations in KRAS(G12V or G13D), NRAS(Q61K or G13R), MRAS(Q71R) and/or BRAF(G596R), mirroring observations in patients. Single-cell sequencing in an isogenic lineage identified secondary RAS and/or BRAF mutations in the same cells as KRAS(G12C), where they bypassed inhibition without affecting target inactivation. Genetic or pharmacological targeting of ERK signalling intermediates enhanced the antiproliferative effect of G12C inhibitor treatment in models with acquired RAS or BRAF mutations. Our study thus suggests a heterogenous pattern of resistance with multiple subclonal events emerging during G12C inhibitor treatment. A subset of patients in our cohort acquired oncogenic KRAS, NRAS or BRAF mutations, and resistance in this setting may be delayed by co-targeting of ERK signalling intermediates. These findings merit broader evaluation in prospective clinical trials.
Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Acetonitrilas/farmacologia , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular , Estudos de Coortes , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Piridinas/farmacologia , Piridinas/uso terapêutico , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The M2 muscarinic acetylcholine receptor (M2R) is a prototypical GPCR that plays important roles in regulating heart rate and CNS functions. Crystal structures provide snapshots of the M2R in inactive and active states, but the allosteric link between the ligand binding pocket and cytoplasmic surface remains poorly understood. Here we used solution NMR to examine the structure and dynamics of the M2R labeled with 13CH3-ε-methionine upon binding to various orthosteric and allosteric ligands having a range of efficacy for both G protein activation and arrestin recruitment. We observed ligand-specific changes in the NMR spectra of 13CH3-ε-methionine probes in the M2R extracellular domain, transmembrane core, and cytoplasmic surface, allowing us to correlate ligand structure with changes in receptor structure and dynamics. We show that the M2R has a complex energy landscape in which ligands with different efficacy profiles stabilize distinct receptor conformations.