RESUMO
Although RAF monomer inhibitors (type I.5, BRAF(V600)) are clinically approved for the treatment of BRAFV600-mutant melanoma, they are ineffective in non-BRAFV600 mutant cells1-3. Belvarafenib is a potent and selective RAF dimer (type II) inhibitor that exhibits clinical activity in patients with BRAFV600E- and NRAS-mutant melanomas. Here we report the first-in-human phase I study investigating the maximum tolerated dose, and assessing the safety and preliminary efficacy of belvarafenib in BRAFV600E- and RAS-mutated advanced solid tumours (NCT02405065, NCT03118817). By generating belvarafenib-resistant NRAS-mutant melanoma cells and analysing circulating tumour DNA from patients treated with belvarafenib, we identified new recurrent mutations in ARAF within the kinase domain. ARAF mutants conferred resistance to belvarafenib in both a dimer- and a kinase activity-dependent manner. Belvarafenib induced ARAF mutant dimers, and dimers containing mutant ARAF were active in the presence of inhibitor. ARAF mutations may serve as a general resistance mechanism for RAF dimer inhibitors as the mutants exhibit reduced sensitivity to a panel of type II RAF inhibitors. The combination of RAF plus MEK inhibition may be used to delay ARAF-driven resistance and suggests a rational combination for clinical use. Together, our findings reveal specific and compensatory functions for the ARAF isoform and implicate ARAF mutations as a driver of resistance to RAF dimer inhibitors.
Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Melanoma/tratamento farmacológico , Melanoma/genética , Mutação , Proteínas Proto-Oncogênicas A-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas A-raf/genética , Quinases raf/antagonistas & inibidores , Animais , Linhagem Celular , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Melanoma/patologia , Camundongos , Multimerização Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas A-raf/química , Quinases raf/químicaRESUMO
In this issue of Molecular Cell, Terrell et al. (2019) characterize the interactions of RAS-RAF complexes in live cells. Using bioluminescence resonance energy transfer (BRET) technology, they show that individual RAF family members exhibit distinct binding affinities to each RAS family protein, with CRAF exhibiting high binding affinities for all RAS proteins and BRAF exhibiting increased binding affinity for KRAS.
Assuntos
Genes ras , Proteínas Proto-Oncogênicas B-raf/genética , Carcinogênese , Crime , Humanos , Proteínas rasRESUMO
In this issue of Molecular Cell, Ritt et al. (2016) describe a stress-induced checkpoint that effectively suppresses RAS-MAPK signaling. This pathway, activated by agents such as Rigosertib that induce mitotic and oxidative stress, results in JNK-mediated inhibition of RAS-MAPK pathway components SOS and RAF.
Assuntos
Proteínas Proto-Oncogênicas c-raf , Transdução de Sinais/efeitos dos fármacos , Proteínas rasRESUMO
Structure-based design was utilized to optimize 6,6-diaryl substituted dihydropyrone and hydroxylactam to obtain inhibitors of lactate dehydrogenase (LDH) with low nanomolar biochemical and single-digit micromolar cellular potencies. Surprisingly the replacement of a phenyl with a pyridyl moiety in the chemical structure revealed a new binding mode for the inhibitors with subtle conformational change of the LDHA active site. This led to the identification of a potent, cell-active hydroxylactam inhibitor exhibiting an in vivo pharmacokinetic profile suitable for mouse tumor xenograft study.
Assuntos
Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Lactamas/farmacologia , Animais , Linhagem Celular , Cães , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Humanos , L-Lactato Desidrogenase/metabolismo , Lactamas/química , Camundongos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
The Ras-RAF-MEK-ERK signaling axis, commonly mutated in human cancers, is highly regulated to prevent aberrant signaling in healthy cells. One of the pathway modulators, 14-3-3, a constitutive dimer, induces RAF dimerization and activation by binding to a phosphorylated motif C-terminal to the RAF kinase domain. Recent work has suggested that a C-terminal "DTS" region in BRAF is necessary for this 14-3-3-mediated activation. We show that the catalytic activity and ATP binding affinity of the BRAF:14-3-3 complex is insensitive to the presence or absence of the DTS, while the ATP sites of both BRAF molecules are identical and available for binding. We also present a crystal structure of the apo BRAF:14-3-3 complex showing that the DTS is not required to attain the catalytically active conformation of BRAF. Rather, BRAF dimerization induced by 14-3-3 is the key step in activation, allowing the active BRAF:14-3-3 tetramer to achieve catalytic activity comparable to the constitutively active oncogenic BRAF V600E mutant.
Assuntos
Proteínas 14-3-3/química , Proteínas 14-3-3/metabolismo , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas B-raf/metabolismo , Trifosfato de Adenosina/metabolismo , Catálise , Humanos , Ligação Proteica , Multimerização Proteica , Transdução de SinaisRESUMO
KRAS and BRAF activating mutations drive tumorigenesis through constitutive activation of the MAPK pathway. As these tumours represent an area of high unmet medical need, multiple allosteric MEK inhibitors, which inhibit MAPK signalling in both genotypes, are being tested in clinical trials. Impressive single-agent activity in BRAF-mutant melanoma has been observed; however, efficacy has been far less robust in KRAS-mutant disease. Here we show that, owing to distinct mechanisms regulating MEK activation in KRAS- versus BRAF-driven tumours, different mechanisms of inhibition are required for optimal antitumour activity in each genotype. Structural and functional analysis illustrates that MEK inhibitors with superior efficacy in KRAS-driven tumours (GDC-0623 and G-573, the former currently in phase I clinical trials) form a strong hydrogen-bond interaction with S212 in MEK that is critical for blocking MEK feedback phosphorylation by wild-type RAF. Conversely, potent inhibition of active, phosphorylated MEK is required for strong inhibition of the MAPK pathway in BRAF-mutant tumours, resulting in superior efficacy in this genotype with GDC-0973 (also known as cobimetinib), a MEK inhibitor currently in phase III clinical trials. Our study highlights that differences in the activation state of MEK in KRAS-mutant tumours versus BRAF-mutant tumours can be exploited through the design of inhibitors that uniquely target these distinct activation states of MEK. These inhibitors are currently being evaluated in clinical trials to determine whether improvements in therapeutic index within KRAS versus BRAF preclinical models translate to improved clinical responses in patients.
Assuntos
Genes ras/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Neoplasias/enzimologia , Neoplasias/genética , Proteína Oncogênica p21(ras)/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/metabolismo , Regulação Alostérica/efeitos dos fármacos , Azetidinas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Ensaios Clínicos como Assunto , Cristalografia por Raios X , Ativação Enzimática/efeitos dos fármacos , Retroalimentação Fisiológica/efeitos dos fármacos , Células HCT116 , Humanos , Imidazóis/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/química , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Modelos Moleculares , Neoplasias/patologia , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Piperidinas/farmacologia , Proteínas Proto-Oncogênicas B-raf/genéticaRESUMO
Metabolic reprogramming in tumors represents a potential therapeutic target. Herein we used shRNA depletion and a novel lactate dehydrogenase (LDHA) inhibitor, GNE-140, to probe the role of LDHA in tumor growth in vitro and in vivo. In MIA PaCa-2 human pancreatic cells, LDHA inhibition rapidly affected global metabolism, although cell death only occurred after 2 d of continuous LDHA inhibition. Pancreatic cell lines that utilize oxidative phosphorylation (OXPHOS) rather than glycolysis were inherently resistant to GNE-140, but could be resensitized to GNE-140 with the OXPHOS inhibitor phenformin. Acquired resistance to GNE-140 was driven by activation of the AMPK-mTOR-S6K signaling pathway, which led to increased OXPHOS, and inhibitors targeting this pathway could prevent resistance. Thus, combining an LDHA inhibitor with compounds targeting the mitochondrial or AMPK-S6K signaling axis may not only broaden the clinical utility of LDHA inhibitors beyond glycolytically dependent tumors but also reduce the emergence of resistance to LDHA inhibition.
Assuntos
Plasticidade Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Piridonas/farmacologia , Tiofenos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Humanos , L-Lactato Desidrogenase/metabolismo , Modelos Moleculares , Estrutura Molecular , Piridonas/química , Relação Estrutura-Atividade , Tiofenos/químicaRESUMO
The treatment of epidermal growth factor receptor (EGFR)-driven non-small cell lung cancers with the T790M resistance mutation remains a significant unmet medical need. We report the identification of 4-aminoindazolyl-dihydrofuro[3,4-d]pyrimidines as non-covalent inhibitors of EGFR, with excellent activity against the T790M resistance double mutants and initial single activating mutants. Using an optimization strategy focused on structure-based design and improving PK properties through metabolite identification, we obtained advanced leads with high oral exposure.
Assuntos
Receptores ErbB/antagonistas & inibidores , Furanos/farmacologia , Indazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Acrilamidas/farmacologia , Compostos de Anilina/farmacologia , Animais , Sítios de Ligação , Cristalografia por Raios X , Cães , Receptores ErbB/química , Cloridrato de Erlotinib/farmacologia , Furanos/síntese química , Furanos/química , Furanos/farmacocinética , Hepatócitos/metabolismo , Ensaios de Triagem em Larga Escala , Humanos , Ligação de Hidrogênio , Indazóis/síntese química , Indazóis/química , Indazóis/farmacocinética , Camundongos , Microssomos Hepáticos/metabolismo , Mutação Puntual , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Pirimidinas/síntese química , Pirimidinas/química , Pirimidinas/farmacocinética , RatosRESUMO
Activating mutations in KRAS and BRAF are found in more than 30% of all human tumours and 40% of melanoma, respectively, thus targeting this pathway could have broad therapeutic effects. Small molecule ATP-competitive RAF kinase inhibitors have potent antitumour effects on mutant BRAF(V600E) tumours but, in contrast to mitogen-activated protein kinase kinase (MEK) inhibitors, are not potent against RAS mutant tumour models, despite RAF functioning as a key effector downstream of RAS and upstream of MEK. Here we show that ATP-competitive RAF inhibitors have two opposing mechanisms of action depending on the cellular context. In BRAF(V600E) tumours, RAF inhibitors effectively block the mitogen-activated protein kinase (MAPK) signalling pathway and decrease tumour growth. Notably, in KRAS mutant and RAS/RAF wild-type tumours, RAF inhibitors activate the RAF-MEK-ERK pathway in a RAS-dependent manner, thus enhancing tumour growth in some xenograft models. Inhibitor binding activates wild-type RAF isoforms by inducing dimerization, membrane localization and interaction with RAS-GTP. These events occur independently of kinase inhibition and are, instead, linked to direct conformational effects of inhibitors on the RAF kinase domain. On the basis of these findings, we demonstrate that ATP-competitive kinase inhibitors can have opposing functions as inhibitors or activators of signalling pathways, depending on the cellular context. Furthermore, this work provides new insights into the therapeutic use of ATP-competitive RAF inhibitors.
Assuntos
Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neoplasias/patologia , Inibidores de Proteínas Quinases/farmacologia , Quinases raf/antagonistas & inibidores , Quinases raf/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Benzamidas/farmacologia , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Difenilamina/análogos & derivados , Difenilamina/farmacologia , Ativação Enzimática/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Indenos/farmacologia , Indóis/farmacologia , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Multimerização Proteica , Estrutura Terciária de Proteína , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas c-raf/deficiência , Proteínas Proto-Oncogênicas c-raf/genética , Proteínas Proto-Oncogênicas c-raf/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases raf/química , Quinases raf/genética , Proteínas ras/genética , Proteínas ras/metabolismoRESUMO
Optimization of 5-(2,6-dichlorophenyl)-3-hydroxy-2-mercaptocyclohex-2-enone using structure-based design strategies resulted in inhibitors with considerable improvement in biochemical potency against human lactate dehydrogenase A (LDHA). These potent inhibitors were typically selective for LDHA over LDHB isoform (410 fold) and other structurally related malate dehydrogenases, MDH1 and MDH2 (>500 fold). An X-ray crystal structure of enzymatically most potent molecule bound to LDHA revealed two additional interactions associated with enhanced biochemical potency.
Assuntos
Inibidores Enzimáticos/síntese química , L-Lactato Desidrogenase/antagonistas & inibidores , Animais , Cristalografia por Raios X , Cães , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , L-Lactato Desidrogenase/metabolismo , Células Madin Darby de Rim CaninoRESUMO
The Ras gene is frequently mutated in cancer, and mutant Ras drives tumorigenesis. Although Ras is a central oncogene, small molecules that bind to Ras in a well-defined manner and exert inhibitory effects have not been uncovered to date. Through an NMR-based fragment screen, we identified a group of small molecules that all bind to a common site on Ras. High-resolution cocrystal structures delineated a unique ligand-binding pocket on the Ras protein that is adjacent to the switch I/II regions and can be expanded upon compound binding. Structure analysis predicts that compound-binding interferes with the Ras/SOS interactions. Indeed, selected compounds inhibit SOS-mediated nucleotide exchange and prevent Ras activation by blocking the formation of intermediates of the exchange reaction. The discovery of a small-molecule binding pocket on Ras with functional significance provides a new direction in the search of therapeutically effective inhibitors of the Ras oncoprotein.
Assuntos
Nucleotídeos/metabolismo , Proteínas Son Of Sevenless/metabolismo , Proteínas ras/metabolismo , Sítios de Ligação , Linhagem Celular , Humanos , Ligantes , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Proteínas ras/químicaRESUMO
A series of 3,6-disubstituted dihydropyrones were identified as inhibitors of human lactate dehydrogenase (LDH)-A. Structure activity relationships were explored and a series of 6,6-spiro analogs led to improvements in LDHA potency (IC50 <350 nM). An X-ray crystal structure of an improved compound bound to human LDHA was obtained and it illustrated additional opportunities to enhance the potency of these compounds, resulting in the identification of 51 (IC50=30 nM).
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Pironas/síntese química , Pironas/farmacologia , Sítios de Ligação , Cristalografia por Raios X , Humanos , L-Lactato Desidrogenase/metabolismo , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Checkpoint kinase 1 (ChK1) is activated in response to DNA damage, acting to temporarily block cell cycle progression and allow for DNA repair. It is envisaged that inhibition of ChK1 will sensitize tumor cells to treatment with DNA-damaging therapies, and may enhance the therapeutic window. High throughput screening identified carboxylate-containing diarylpyrazines as a prominent hit series, but with limited biochemical potency and no cellular activity. Through a series of SAR investigations and X-ray crystallographic analysis the critical role of polar contacts with conserved waters in the kinase back pocket was established. Structure-based design, guided by in silico modeling, transformed the series to better satisfy these contacts and the novel 1,7-diazacarbazole class of inhibitors was discovered. Here we present the genesis of this novel series and the identification of GNE-783, a potent, selective and orally bioavailable inhibitor of ChK1.
Assuntos
Compostos Aza/química , Carbazóis/química , Carbolinas/farmacologia , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/química , Administração Oral , Animais , Carbolinas/administração & dosagem , Carbolinas/síntese química , Carbolinas/farmacocinética , Quinase 1 do Ponto de Checagem , Cristalografia por Raios X , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Sinergismo Farmacológico , Humanos , Camundongos , Conformação Proteica , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Ratos , Relação Estrutura-Atividade , Distribuição Tecidual , GencitabinaRESUMO
A novel class of 3-hydroxy-2-mercaptocyclohex-2-enone-containing inhibitors of human lactate dehydrogenase (LDH) was identified through a high-throughput screening approach. Biochemical and surface plasmon resonance experiments performed with a screening hit (LDHA IC50=1.7 µM) indicated that the compound specifically associated with human LDHA in a manner that required simultaneous binding of the NADH co-factor. Structural variation of this screening hit resulted in significant improvements in LDHA biochemical inhibition activity (best IC50=0.18 µM). Two crystal structures of optimized compounds bound to human LDHA were obtained and explained many of the observed structure-activity relationships. In addition, an optimized inhibitor exhibited good pharmacokinetic properties after oral administration to rats (F=45%).
Assuntos
Cicloexanonas/farmacologia , Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Compostos de Sulfidrila/farmacologia , Administração Oral , Animais , Cicloexanonas/administração & dosagem , Cicloexanonas/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Ensaios de Triagem em Larga Escala , Humanos , L-Lactato Desidrogenase/metabolismo , Modelos Moleculares , Estrutura Molecular , Ratos , Relação Estrutura-Atividade , Compostos de Sulfidrila/administração & dosagem , Compostos de Sulfidrila/químicaRESUMO
A series of N-7-methyl-imidazolopyrimidine inhibitors of the mTOR kinase have been designed and prepared, based on the hypothesis that the N-7-methyl substituent on imidazolopyrimidine would impart selectivity for mTOR over the related PI3Kα and δ kinases. The corresponding N-Me substituted pyrrolo[3,2-d]pyrimidines and pyrazolo[4,3-d]pyrimidines also show potent mTOR inhibition with selectivity toward both PI3α and δ kinases. The most potent compound synthesized is pyrazolo[4,3-d]pyrimidine 21c. Compound 21c shows a Ki of 2 nM against mTOR inhibition, remarkable selectivity (>2900×) over PI3 kinases, and excellent potency in cell-based assays.
Assuntos
Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/metabolismoRESUMO
A 2-amino-5-aryl-pyrazine was identified as an inhibitor of human lactate dehydrogenase A (LDHA) via a biochemical screening campaign. Biochemical and biophysical experiments demonstrated that the compound specifically interacted with human LDHA. Structural variation of the screening hit resulted in improvements in LDHA biochemical inhibition and pharmacokinetic properties. A crystal structure of an improved compound bound to human LDHA was also obtained and it explained many of the observed structure-activity relationships.
Assuntos
Inibidores Enzimáticos/química , L-Lactato Desidrogenase/antagonistas & inibidores , Pirazinas/química , Animais , Sítios de Ligação , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Meia-Vida , Humanos , L-Lactato Desidrogenase/metabolismo , Masculino , Microssomos Hepáticos/metabolismo , Estrutura Terciária de Proteína , Pirazinas/síntese química , Pirazinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
A novel 2-thio-6-oxo-1,6-dihydropyrimidine-containing inhibitor of human lactate dehydrogenase (LDH) was identified by high-throughput screening (IC50=8.1 µM). Biochemical, surface plasmon resonance, and saturation transfer difference NMR experiments indicated that the compound specifically associated with human LDHA in a manner that required simultaneous binding of the NADH co-factor. Structural variation of the screening hit resulted in significant improvements in LDHA biochemical inhibition activity (best IC50=0.48 µM). A crystal structure of an optimized compound bound to human LDHA was obtained and explained many of the observed structure-activity relationships.
Assuntos
Inibidores Enzimáticos/química , L-Lactato Desidrogenase/antagonistas & inibidores , Pirimidinas/química , Sítios de Ligação , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Humanos , Ligação de Hidrogênio , L-Lactato Desidrogenase/metabolismo , Espectroscopia de Ressonância Magnética , NAD/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Pirimidinas/síntese química , Pirimidinas/metabolismo , Relação Estrutura-Atividade , Ressonância de Plasmônio de SuperfícieRESUMO
Targeted degradation of proteins by chimeric heterobifunctional degraders has emerged as a major drug discovery paradigm. Despite the increased interest in this approach, the criteria dictating target protein degradation by a degrader remain poorly understood, and potent target engagement by a degrader does not strongly correlate with target degradation. In this study, we present the biochemical characterization of an epidermal growth factor receptor (EGFR) degrader that potently binds both wild-type and mutant EGFR, but only degrades EGFR mutant variants. Mechanistic studies reveal that ternary complex half-life strongly correlates with processive ubiquitination with purified components and mutant-selective degradation in cells. We present cryoelectron microscopy and hydrogen-deuterium exchange mass spectroscopy data on wild-type and mutant EGFR ternary complexes, which demonstrate that potent target degradation can be achieved in the absence of stable compound-induced protein-protein interactions. These results highlight the importance of considering target conformation during degrader development as well as leveraging heterobifunctional ligand binding kinetics to achieve robust target degradation.
RESUMO
With structural guidance, tropane-derived HTS hits were modified to optimize for HSP90 inhibition and a desirable in vivo profile. Through an iterative SAR development process 12i (XL888) was discovered and shown to reduce HSP90 client protein content in PD studies. Furthermore, efficacy experiments performed in a NCI-N87 mouse xenograft model demonstrated tumor regression in some dosing regimens.
Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Compostos Azabicíclicos/química , Compostos Azabicíclicos/uso terapêutico , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Ácidos Ftálicos/química , Ácidos Ftálicos/uso terapêutico , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Compostos Azabicíclicos/farmacocinética , Compostos Azabicíclicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Descoberta de Drogas , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Camundongos , Modelos Moleculares , Neoplasias/metabolismo , Neoplasias/patologia , Ácidos Ftálicos/farmacocinética , Ácidos Ftálicos/farmacologiaRESUMO
Genetic and non-genetic heterogeneity within cancer cell populations represent major challenges to anticancer therapies. We currently lack robust methods to determine how preexisting and adaptive features affect cellular responses to therapies. Here, by conducting clonal fitness mapping and transcriptional characterization using expressed barcodes and single-cell RNA sequencing (scRNA-seq), we have developed tracking differential clonal response by scRNA-seq (TraCe-seq). TraCe-seq is a method that captures at clonal resolution the origin, fate and differential early adaptive transcriptional programs of cells in a complex population in response to distinct treatments. We used TraCe-seq to benchmark how next-generation dual epidermal growth factor receptor (EGFR) inhibitor-degraders compare to standard EGFR kinase inhibitors in EGFR-mutant lung cancer cells. We identified a loss of antigrowth activity associated with targeted degradation of EGFR protein and an essential role of the endoplasmic reticulum (ER) protein processing pathway in anti-EGFR therapeutic efficacy. Our results suggest that targeted degradation is not always superior to enzymatic inhibition and establish TraCe-seq as an approach to study how preexisting transcriptional programs affect treatment responses.