RESUMO
KRAS is one of the most commonly mutated proteins in cancer, and efforts to directly inhibit its function have been continuing for decades. The most successful of these has been the development of covalent allele-specific inhibitors that trap KRAS G12C in its inactive conformation and suppress tumour growth in patients1-7. Whether inactive-state selective inhibition can be used to therapeutically target non-G12C KRAS mutants remains under investigation. Here we report the discovery and characterization of a non-covalent inhibitor that binds preferentially and with high affinity to the inactive state of KRAS while sparing NRAS and HRAS. Although limited to only a few amino acids, the evolutionary divergence in the GTPase domain of RAS isoforms was sufficient to impart orthosteric and allosteric constraints for KRAS selectivity. The inhibitor blocked nucleotide exchange to prevent the activation of wild-type KRAS and a broad range of KRAS mutants, including G12A/C/D/F/V/S, G13C/D, V14I, L19F, Q22K, D33E, Q61H, K117N and A146V/T. Inhibition of downstream signalling and proliferation was restricted to cancer cells harbouring mutant KRAS, and drug treatment suppressed KRAS mutant tumour growth in mice, without having a detrimental effect on animal weight. Our study suggests that most KRAS oncoproteins cycle between an active state and an inactive state in cancer cells and are dependent on nucleotide exchange for activation. Pan-KRAS inhibitors, such as the one described here, have broad therapeutic implications and merit clinical investigation in patients with KRAS-driven cancers.
Assuntos
Neoplasias , Proteínas Proto-Oncogênicas p21(ras) , Transdução de Sinais , Animais , Camundongos , Peso Corporal , Ativação Enzimática , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Nucleotídeos/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Especificidade por SubstratoRESUMO
Transcription factors are generally considered challenging, if not "undruggable", targets but they promise new therapeutic options due to their fundamental involvement in many diseases. In this study, we aim to assess the ligandability of the C-terminal Rel-homology domain of nuclear factor of activated T cells 1 (NFAT1), a TF implicated in T-cell regulation. Using a combination of experimental and computational approaches, we demonstrate that small molecule fragments can indeed bind to this protein domain. The newly identified binder is the first small molecule binder to NFAT1 validated with biophysical methods and an elucidated binding mode by X-ray crystallography. The reported eutomer/distomer pair provides a strong basis for potential exploration of higher potency binders on the path toward degrader or glue modalities.
Assuntos
Fatores de Transcrição NFATC , Sítios de Ligação , Cristalografia por Raios X , Ligantes , Fatores de Transcrição NFATC/metabolismo , Fatores de Transcrição NFATC/química , Ligação Proteica , Domínios Proteicos , Relação Estrutura-AtividadeRESUMO
Here, we report the fragment-based discovery of BI-9321, a potent, selective and cellular active antagonist of the NSD3-PWWP1 domain. The human NSD3 protein is encoded by the WHSC1L1 gene located in the 8p11-p12 amplicon, frequently amplified in breast and squamous lung cancer. Recently, it was demonstrated that the PWWP1 domain of NSD3 is required for the viability of acute myeloid leukemia cells. To further elucidate the relevance of NSD3 in cancer biology, we developed a chemical probe, BI-9321, targeting the methyl-lysine binding site of the PWWP1 domain with sub-micromolar in vitro activity and cellular target engagement at 1 µM. As a single agent, BI-9321 downregulates Myc messenger RNA expression and reduces proliferation in MOLM-13 cells. This first-in-class chemical probe BI-9321, together with the negative control BI-9466, will greatly facilitate the elucidation of the underexplored biological function of PWWP domains.
Assuntos
Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Proteínas Nucleares/antagonistas & inibidores , Sistemas CRISPR-Cas , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Domínios Proteicos , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismoRESUMO
Myeloid cell leukemia 1 (Mcl-1) is a key regulator of the intrinsic apoptosis pathway. Overexpression of Mcl-1 is correlated with high tumor grade, poor survival, and both intrinsic and acquired resistance to cancer therapies. Herein, we disclose the structure-guided design of a small molecule Mcl-1 inhibitor, compound 26, that binds to Mcl-1 with subnanomolar affinity, inhibits growth in cell culture assays, and possesses low clearance in mouse and dog pharmacokinetic (PK) experiments. Evaluation of 26 as a single agent in Mcl-1 sensitive hematological and solid tumor xenograft models resulted in regressions. Co-treatment of Mcl-1-sensitive and Mcl-1 insensitive lung cancer derived xenografts with 26 and docetaxel or topotecan, respectively, resulted in an enhanced tumor response. These findings support the premise that pro-apoptotic priming of tumor cells by other therapies in combination with Mcl-1 inhibition may significantly expand the subset of cancers in which Mcl-1 inhibitors may prove beneficial.
Assuntos
Antineoplásicos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Cães , Relação Estrutura-Atividade , Feminino , Descoberta de Drogas , Taxoides/farmacologia , Taxoides/farmacocinética , Taxoides/uso terapêutico , Taxoides/química , Docetaxel/farmacologia , Docetaxel/uso terapêutico , Docetaxel/farmacocinética , Docetaxel/químicaRESUMO
Activating mutations in KRAS are the most frequent oncogenic alterations in cancer. The oncogenic hotspot position 12, located at the lip of the switch II pocket, offers a covalent attachment point for KRASG12C inhibitors. To date, KRASG12C inhibitors have been discovered by first covalently binding to the cysteine at position 12 and then optimizing pocket binding. We report on the discovery of the in vivo active KRASG12C inhibitor BI-0474 using a different approach, in which small molecules that bind reversibly to the switch II pocket were identified and then optimized for non-covalent binding using structure-based design. Finally, the Michael acceptor containing warhead was attached. Our approach offers not only an alternative approach to discovering KRASG12C inhibitors but also provides a starting point for the discovery of inhibitors against other oncogenic KRAS mutants.
Assuntos
Neoplasias , Proteínas Proto-Oncogênicas p21(ras) , Humanos , Proteínas Proto-Oncogênicas p21(ras)/genética , Genes ras , Mutação , Neoplasias/genética , CisteínaRESUMO
KRAS, the most common oncogenic driver in human cancers, is controlled and signals primarily through protein-protein interactions (PPIs). The interaction between KRAS and SOS1, crucial for the activation of KRAS, is a typical, challenging PPI with a large contact surface area and high affinity. Here, we report that the addition of only one atom placed between Y884SOS1 and A73KRAS is sufficient to convert SOS1 activators into SOS1 inhibitors. We also disclose the discovery of BI-3406. Combination with the upstream EGFR inhibitor afatinib shows in vivo efficacy against KRASG13D mutant colorectal tumor cells, demonstrating the utility of BI-3406 to probe SOS1 biology. These findings challenge the dogma that large molecules are required to disrupt challenging PPIs. Instead, a "foot in the door" approach, whereby single atoms or small functional groups placed between key PPI interactions, can lead to potent inhibitors even for challenging PPIs such as SOS1-KRAS.
Assuntos
Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína SOS1/metabolismo , Afatinib/química , Afatinib/metabolismo , Afatinib/uso terapêutico , Regulação Alostérica/efeitos dos fármacos , Sítios de Ligação , Domínio Catalítico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Mapas de Interação de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Quinazolinas/química , Quinazolinas/metabolismo , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Proteína SOS1/agonistas , Proteína SOS1/antagonistas & inibidores , Proteína SOS1/genéticaRESUMO
KRAS is the most frequently mutated driver of pancreatic, colorectal, and non-small cell lung cancers. Direct KRAS blockade has proved challenging, and inhibition of a key downstream effector pathway, the RAF-MEK-ERK cascade, has shown limited success because of activation of feedback networks that keep the pathway in check. We hypothesized that inhibiting SOS1, a KRAS activator and important feedback node, represents an effective approach to treat KRAS-driven cancers. We report the discovery of a highly potent, selective, and orally bioavailable small-molecule SOS1 inhibitor, BI-3406, that binds to the catalytic domain of SOS1, thereby preventing the interaction with KRAS. BI-3406 reduces formation of GTP-loaded RAS and limits cellular proliferation of a broad range of KRAS-driven cancers. Importantly, BI-3406 attenuates feedback reactivation induced by MEK inhibitors and thereby enhances sensitivity of KRAS-dependent cancers to MEK inhibition. Combined SOS1 and MEK inhibition represents a novel and effective therapeutic concept to address KRAS-driven tumors. SIGNIFICANCE: To date, there are no effective targeted pan-KRAS therapies. In-depth characterization of BI-3406 activity and identification of MEK inhibitors as effective combination partners provide an attractive therapeutic concept for the majority of KRAS-mutant cancers, including those fueled by the most prevalent mutant KRAS oncoproteins, G12D, G12V, G12C, and G13D.See related commentary by Zhao et al., p. 17.This article is highlighted in the In This Issue feature, p. 1.
Assuntos
Neoplasias Pulmonares , Proteínas Proto-Oncogênicas p21(ras) , Linhagem Celular Tumoral , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno , Mutação , Nucleotídeos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genéticaRESUMO
Human cytomegalovirus (HCMV) remains a serious threat for immunocompromised individuals, including transplant recipients and newborns. To date, all drugs licensed for the treatment of HCMV infection and disease target the viral DNA polymerase. Although these drugs are effective, several drawbacks are associated with their use, including toxicity and emergence of drug resistance. Hence, new and improved antivirals with novel molecular targets are urgently needed. Here we report on the antiviral properties of AIC246, a representative of a novel class of low-molecular-weight compounds that is currently undergoing clinical phase II studies. The anti-HCMV activity of AIC246 was evaluated in vitro and in vivo using various cell culture assays and an engineered mouse xenograft model. In addition, antiviral properties of the drug were characterized in comparison to the current gold standard ganciclovir. We demonstrate that AIC246 exhibits excellent in vitro inhibitory activity against HCMV laboratory strains and clinical isolates, retains activity against ganciclovir-resistant viruses, is well tolerated in different cell types (median selectivity index, 18,000), and exerts a potent in vivo efficacy in a mouse xenograft model. Moreover, we show that the antiviral block induced by AIC246 is reversible and the efficacy of the drug is not significantly affected by cell culture variations such as cell type or multiplicity of infection. Finally, initial mode-of-action analyses reveal that AIC246 targets a process in the viral replication cycle that occurs later than DNA synthesis. Thus, AIC246 acts via a mode of action that differs from that of polymerase inhibitors like ganciclovir.
Assuntos
Ácido Acético/farmacologia , Antivirais/farmacologia , Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus/efeitos dos fármacos , Quinazolinas/farmacologia , Ácido Acético/administração & dosagem , Ácido Acético/química , Animais , Antivirais/administração & dosagem , Antivirais/química , Linhagem Celular , Células Cultivadas , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/virologia , Efeito Citopatogênico Viral , Derme/citologia , Modelos Animais de Doenças , Fibroblastos/virologia , Humanos , Pulmão/citologia , Camundongos , Camundongos SCID , Quinazolinas/administração & dosagem , Quinazolinas/química , Transplante Heterólogo , Resultado do Tratamento , Replicação Viral/efeitos dos fármacosRESUMO
The epidermal growth factor receptor (EGFR), when carrying an activating mutation like del19 or L858R, acts as an oncogenic driver in a subset of lung tumors. While tumor responses to tyrosine kinase inhibitors (TKIs) are accompanied by marked tumor shrinkage, the response is usually not durable. Most patients relapse within two years of therapy often due to acquisition of an additional mutation in EGFR kinase domain that confers resistance to TKIs. Crucially, oncogenic EGFR harboring both resistance mutations, T790M and C797S, can no longer be inhibited by currently approved EGFR TKIs. Here, we describe the discovery of BI-4020, which is a noncovalent, wild-type EGFR sparing, macrocyclic TKI. BI-4020 potently inhibits the above-described EGFR variants and induces tumor regressions in a cross-resistant EGFRdel19â¯T790Mâ¯C797S xenograft model. Key was the identification of a highly selective but moderately potent benzimidazole followed by complete rigidification of the molecule through macrocyclization.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Animais , Antineoplásicos/farmacocinética , Benzimidazóis/química , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ciclização , Entropia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/química , Receptores ErbB/genética , Feminino , Hepatócitos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Transgênicos , Mutação , Conformação Proteica , Inibidores de Proteínas Quinases/farmacocinética , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Drug-like and lead-like hits derived from HTS campaigns provide good starting points for lead optimization. However, too strong emphasis on potency as hit-selection parameter might hamper the success of such projects. A detailed absorption, distribution, metabolism, excretion and toxicology (ADME-Tox) profiling is needed to help identify hits with a minimum number of (known) liabilities. This is particularly true for drug-like hits. Herein, we describe how to break down large numbers of screening hits and we provide a comprehensive overview of the strengths and weaknesses for each structural class. The overall profile (e.g. ligand efficiency, selectivity and ADME-Tox) is the distinctive feature that will define the priority for follow-up.
Assuntos
Desenho de Fármacos , Administração Oral , Farmacocinética , ToxicologiaRESUMO
Scaffold modification based on Wang's pioneering MDM2-p53 inhibitors led to novel, chemically stable spiro-oxindole compounds bearing a spiro[3H-indole-3,2'-pyrrolidin]-2(1H)-one scaffold that are not prone to epimerization as observed for the initial spiro[3H-indole-3,3'-pyrrolidin]-2(1H)-one scaffold. Further structure-based optimization inspired by natural product architectures led to a complex fused ring system ideally suited to bind to the MDM2 protein and to interrupt its protein-protein interaction (PPI) with TP53. The compounds are highly selective and show in vivo efficacy in a SJSA-1 xenograft model even when given as a single dose as demonstrated for 4-[(3S,3'S,3'aS,5'R,6'aS)-6-chloro-3'-(3-chloro-2-fluorophenyl)-1'-(cyclopropylmethyl)-2-oxo-1,2,3',3'a,4',5',6',6'a-octahydro-1'H-spiro[indole-3,2'-pyrrolo[3,2-b]pyrrole]-5'-yl]benzoic acid (BI-0252).
Assuntos
Descoberta de Drogas , Indóis/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Pirrolidinonas/farmacologia , Compostos de Espiro/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Administração Oral , Relação Dose-Resposta a Droga , Humanos , Indóis/administração & dosagem , Indóis/química , Modelos Moleculares , Estrutura Molecular , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Pirrolidinonas/administração & dosagem , Pirrolidinonas/química , Compostos de Espiro/administração & dosagem , Compostos de Espiro/química , Relação Estrutura-Atividade , Proteína Supressora de Tumor p53/metabolismoRESUMO
Due to their high density of functional groups and their availability in a variety of diastereomeric forms, monosaccharides are considered attractive scaffolds for combinatorial chemistry that allow the attachment and defined spatial alignment of up to five different pharmacophoric groups. For their application in combinatorial syntheses on solid phase, a set of selectively removable hydroxy protecting groups in combination with a cleavable anchor is required. Herein, we report on the construction and use of a versatile multivalent glucose building block for parallel synthesis on the solid phase.
Assuntos
Técnicas de Química Combinatória , Glucose/química , Alquilação , Cromatografia Líquida de Alta Pressão , Reagentes de Ligações Cruzadas , Cristalografia por Raios X , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray , Tioglicosídeos/químicaRESUMO
Four orthogonally stable protecting groups and a selectively cleavable anchor that are stable under basic conditions are required in order that carbohydrates can be employed as chiral polyfunctional scaffolds in combinatorial solid-phase syntheses of high diversity. The schematic representation shows the combinatorial synthesis with a carbohydrate scaffold (SG=protecting group, A=anchor, P=polymer carrier), which proceeds by sequential selective deprotection, functionalization, washing of the solid phase, and cleavage of the anchor.
RESUMO
The need for in silico characterization of HTS hit structures as part of a data-driven hit-selection process is demonstrated. A solution is described in the form of an in silico ADMET traffic light and PhysChem scoring system. This has been extensively validated with in-house data at Bayer, published data, and a collection of launched small-molecule oral drugs.