RESUMO
Malignant tumors exhibit high degrees of genomic heterogeneity at the cellular level, leading to the view that subpopulations of tumor cells drive growth and treatment resistance. To examine the degree to which tumors also exhibit metabolic heterogeneity at the level of individual cells, we employed multi-isotope imaging mass spectrometry (MIMS) to quantify utilization of stable isotopes of glucose and glutamine along with a label for cell division. Mouse models of melanoma and malignant peripheral nerve sheath tumors (MPNSTs) exhibited striking heterogeneity of substrate utilization, evident in both proliferating and non-proliferating cells. We identified a correlation between metabolic heterogeneity, proliferation, and therapeutic resistance. Heterogeneity in metabolic substrate usage as revealed by incorporation of glucose and glutamine tracers is thus a marker for tumor proliferation. Collectively, our data demonstrate that MIMS provides a powerful tool with which to dissect metabolic functions of individual cells within the native tumor environment.
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While KRAS mutations are common in non-small cell lung cancer (NSCLC), effective treatments are lacking. Here, we report that half of KRAS-mutant NSCLCs aberrantly express the homeobox protein HOXC10, largely due to unappreciated defects in PRC2, which confers sensitivity to combined BET/MEK inhibitors in xenograft and PDX models. Efficacy of the combination is dependent on suppression of HOXC10 by BET inhibitors. We further show that HOXC10 regulates the expression of pre-replication complex (pre-RC) proteins in sensitive tumors. Accordingly, BET/MEK inhibitors suppress pre-RC proteins in cycling cells, triggering stalled replication, DNA damage, and death. These studies reveal a promising therapeutic strategy for KRAS-mutant NSCLCs, identify a predictive biomarker of response, and define a subset of NSCLCs with a targetable epigenetic vulnerability.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Epigênese Genética , Proteínas de Homeodomínio/metabolismo , Neoplasias Pulmonares/patologia , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Acrilonitrila/análogos & derivados , Acrilonitrila/farmacologia , Compostos de Anilina/farmacologia , Animais , Apoptose , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , MAP Quinase Quinase 1/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas/antagonistas & inibidores , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas. Combining Hsp90 inhibitors to enhance endoplasmic reticulum stress with mTOR inhibition results in dramatic MPNST shrinkage in a genetically engineered MPNST mouse model. Ganetespib is an injectable potent small molecule inhibitor of Hsp90. Sirolimus is an oral mTOR inhibitor. We sought to determine the safety, tolerability, and recommended dose of ganetespib and sirolimus in patients with refractory sarcomas and assess clinical benefits in patients with unresectable/refractory MPNSTs. Patients and Methods. In this multi-institutional, open-label, phase 1/2 study of ganetespib and sirolimus, patients ≥16 years with histologically confirmed refractory sarcoma (phase 1) or MPNST (phase 2) were eligible. A conventional 3 + 3 dose escalation design was used for phase 1. Pharmacokinetic and pharmacodynamic measures were evaluated. Primary objectives of phase 2 were to determine the clinical benefit rate (CBR) of this combination in MPNSTs. Patient-reported outcomes assessed pain. RESULTS: Twenty patients were enrolled (10 per phase). Toxicities were manageable; most frequent non-DLTs were diarrhea, elevated liver transaminases, and fatigue. The recommended dose of ganetespib was 200 mg/m2 intravenously on days 1, 8, and 15 with sirolimus 4 mg orally once daily with day 1 loading dose of 12 mg. In phase 1, one patient with leiomyosarcoma achieved a sustained partial response. In phase 2, no responses were observed. The median number of cycles treated was 2 (1-4). Patients did not meet the criteria for clinical benefit as defined per protocol. Pain ratings decreased or were stable. CONCLUSION: Despite promising preclinical rationale and tolerability of the combination therapy, no responses were observed, and the study did not meet parameters for further evaluation in MPNSTs. This trial was registered with (NCT02008877).
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Pancreatic ductal adenocarcinoma is an aggressive cancer with limited treatment options1. Approximately 10% of cases exhibit familial predisposition, but causative genes are not known in most families2. We perform whole-genome sequence analysis in a family with multiple cases of pancreatic ductal adenocarcinoma and identify a germline truncating mutation in the member of the RAS oncogene family-like 3 (RABL3) gene. Heterozygous rabl3 mutant zebrafish show increased susceptibility to cancer formation. Transcriptomic and mass spectrometry approaches implicate RABL3 in RAS pathway regulation and identify an interaction with RAP1GDS1 (SmgGDS), a chaperone regulating prenylation of RAS GTPases3. Indeed, the truncated mutant RABL3 protein accelerates KRAS prenylation and requires RAS proteins to promote cell proliferation. Finally, evidence in patient cohorts with developmental disorders implicates germline RABL3 mutations in RASopathy syndromes. Our studies identify RABL3 mutations as a target for genetic testing in cancer families and uncover a mechanism for dysregulated RAS activity in development and cancer.
Assuntos
Carcinoma Ductal Pancreático/patologia , Carcinoma/patologia , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Neoplasias Pancreáticas/patologia , Prenilação , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas rab de Ligação ao GTP/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Animais , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Proliferação de Células , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Linhagem , Proteínas Proto-Oncogênicas p21(ras)/genética , Homologia de Sequência , Peixe-ZebraRESUMO
Although the majority of BRAF-mutant melanomas respond to BRAF/MEK inhibitors, these agents are not typically curative. Moreover, they are largely ineffective in NRAS- and NF1-mutant tumors. Here we report that genetic and chemical suppression of HDAC3 potently cooperates with MAPK pathway inhibitors in all three RAS pathway-driven tumors. Specifically, we show that entinostat dramatically enhances tumor regression when combined with BRAF/MEK inhibitors, in both models that are sensitive or relatively resistant to these agents. Interestingly, MGMT expression predicts responsiveness and marks tumors with latent defects in DNA repair. BRAF/MEK inhibitors enhance these defects by suppressing homologous recombination genes, inducing a BRCA-like state; however, addition of entinostat triggers the concomitant suppression of nonhomologous end-joining genes, resulting in a chemical synthetic lethality caused by excessive DNA damage. Together, these studies identify melanomas with latent DNA repair defects, describe a promising drug combination that capitalizes on these defects, and reveal a tractable therapeutic biomarker. SIGNIFICANCE: BRAF/MEK inhibitors are not typically curative in BRAF-mutant melanomas and are ineffective in NRAS- and NF1-mutant tumors. We show that HDAC inhibitors dramatically enhance the efficacy of BRAF/MEK inhibitors in sensitive and insensitive RAS pathway-driven melanomas by coordinately suppressing two DNA repair pathways, and identify a clinical biomarker that predicts responsiveness.See related commentary by Lombard et al., p. 469.This article is highlighted in the In This Issue feature, p. 453.
Assuntos
Reparo do DNA/genética , Genes ras/genética , MAP Quinase Quinase Quinases/genética , Melanoma/genética , Humanos , Proteínas Proto-Oncogênicas B-rafRESUMO
Bromodomain and extraterminal (BET) domain inhibitors (BETis) show efficacy on NUT midline carcinoma (NMC). However, not all NMC patients respond, and responders eventually develop resistance and relapse. Using CRISPR and ORF expression screens, we systematically examined the ability of cancer drivers to mediate resistance of NMC to BETis and uncovered six general classes/pathways mediating resistance. Among these, we showed that RRAS2 attenuated the effect of JQ1 in part by sustaining ERK pathway function during BRD4 inhibition. Furthermore, overexpression of Kruppel-like factor 4 (KLF4), mediated BETi resistance in NMC cells through restoration of the E2F and MYC gene expression program. Finally, we found that expression of cyclin D1 or an oncogenic cyclin D3 mutant or RB1 loss protected NMC cells from BETi-induced cell cycle arrest. Consistent with these findings, cyclin-dependent kinase 4/6 (CDK4/6) inhibitors showed synergistic effects with BETis on NMC in vitro as well as in vivo, thereby establishing a potential two-drug therapy for NMC.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Azepinas/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Triazóis/uso terapêutico , Animais , Azepinas/farmacologia , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Ciclinas/metabolismo , Resistencia a Medicamentos Antineoplásicos , Fatores de Transcrição E2F/genética , Fatores de Transcrição E2F/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Expressão Gênica , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas de Membrana/genética , Camundongos , Camundongos Nus , Proteínas Monoméricas de Ligação ao GTP/genética , Mutação , Proteínas de Neoplasias , Proteínas Nucleares/antagonistas & inibidores , Proteínas Oncogênicas/antagonistas & inibidores , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Piridinas/farmacologia , Piridinas/uso terapêutico , Fatores de Transcrição/antagonistas & inibidores , Triazóis/farmacologiaRESUMO
Diverse pathways drive resistance to BRAF/MEK inhibitors in BRAF-mutant melanoma, suggesting that durable control of resistance will be a challenge. By combining statistical modeling of genomic data from matched pre-treatment and post-relapse patient tumors with functional interrogation of >20 in vitro and in vivo resistance models, we discovered that major pathways of resistance converge to activate the transcription factor, c-MYC (MYC). MYC expression and pathway gene signatures were suppressed following drug treatment, and then rebounded during progression. Critically, MYC activation was necessary and sufficient for resistance, and suppression of MYC activity using genetic approaches or BET bromodomain inhibition was sufficient to resensitize cells and delay BRAFi resistance. Finally, MYC-driven, BRAFi-resistant cells are hypersensitive to the inhibition of MYC synthetic lethal partners, including SRC family and c-KIT tyrosine kinases, as well as glucose, glutamine, and serine metabolic pathways. These insights enable the design of combination therapies that select against resistance evolution.
Assuntos
Melanoma/tratamento farmacológico , Proteínas Proto-Oncogênicas c-myc/metabolismo , Antineoplásicos Hormonais/uso terapêutico , Benzimidazóis/farmacologia , Linhagem Celular Tumoral , Estradiol/análogos & derivados , Estradiol/uso terapêutico , Evolução Molecular , Feminino , Fulvestranto , Humanos , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Indóis/farmacologia , Masculino , Oximas/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Piridonas/uso terapêutico , Pirimidinonas/uso terapêutico , Quinolinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologiaRESUMO
Preclinical studies using genetically engineered mouse models (GEMM) have the potential to expedite the development of effective new therapies; however, they are not routinely integrated into drug development pipelines. GEMMs may be particularly valuable for investigating treatments for less common cancers, which frequently lack alternative faithful models. Here, we describe a multicenter cooperative group that has successfully leveraged the expertise and resources from philanthropic foundations, academia, and industry to advance therapeutic discovery and translation using GEMMs as a preclinical platform. This effort, known as the Neurofibromatosis Preclinical Consortium (NFPC), was established to accelerate new treatments for tumors associated with neurofibromatosis type 1 (NF1). At its inception, there were no effective treatments for NF1 and few promising approaches on the horizon. Since 2008, participating laboratories have conducted 95 preclinical trials of 38 drugs or combinations through collaborations with 18 pharmaceutical companies. Importantly, these studies have identified 13 therapeutic targets, which have inspired 16 clinical trials. This review outlines the opportunities and challenges of building this type of consortium and highlights how it can accelerate clinical translation. We believe that this strategy of foundation-academic-industry partnering is generally applicable to many diseases and has the potential to markedly improve the success of therapeutic development. Cancer Res; 77(21); 5706-11. ©2017 AACR.
Assuntos
Modelos Animais de Doenças , Descoberta de Drogas/métodos , Neoplasias/tratamento farmacológico , Pesquisa Translacional Biomédica/métodos , Animais , Humanos , Camundongos , Terapia de Alvo Molecular/métodos , Neoplasias/complicações , Neoplasias/diagnóstico , Neurofibromatose 1/complicações , Neurofibromatose 1/diagnóstico , Neurofibromatose 1/tratamento farmacológicoRESUMO
Although agents that inhibit specific oncogenic kinases have been successful in a subset of cancers, there are currently few treatment options for malignancies that lack a targetable oncogenic driver. Nevertheless, during tumor evolution cancers engage a variety of protective pathways, which may provide alternative actionable dependencies. Here, we identify a promising combination therapy that kills NF1-mutant tumors by triggering catastrophic oxidative stress. Specifically, we show that mTOR and HDAC inhibitors kill aggressive nervous system malignancies and shrink tumors in vivo by converging on the TXNIP/thioredoxin antioxidant pathway, through cooperative effects on chromatin and transcription. Accordingly, TXNIP triggers cell death by inhibiting thioredoxin and activating apoptosis signal-regulating kinase 1 (ASK1). Moreover, this drug combination also kills NF1-mutant and KRAS-mutant non-small cell lung cancers. Together, these studies identify a promising therapeutic combination for several currently untreatable malignancies and reveal a protective nodal point of convergence between these important epigenetic and oncogenic enzymes.Significance: There are no effective therapies for NF1- or RAS-mutant cancers. We show that combined mTOR/HDAC inhibitors kill these RAS-driven tumors by causing catastrophic oxidative stress. This study identifies a promising therapeutic combination and demonstrates that selective enhancement of oxidative stress may be more broadly exploited for developing cancer therapies. Cancer Discov; 7(12); 1450-63. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 1355.
Assuntos
Proteínas de Transporte/genética , Inibidores de Histona Desacetilases/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Proteínas de Transporte/metabolismo , Humanos , Estresse Oxidativo , Transdução de SinaisRESUMO
Neurofibromin 1-mutant (NF1-mutant) cancers are driven by excessive Ras signaling; however, there are currently no effective therapies for these or other Ras-dependent tumors. While combined MEK and mTORC1 suppression causes regression of NF1-deficient malignancies in animal models, the potential toxicity of cotargeting these 2 major signaling pathways in humans may necessitate the identification of more refined, cancer-specific signaling nodes. Here, we have provided evidence that MAPK-interacting kinases (MNKs), which converge on the mTORC1 effector eIF4E, are therapeutic targets in NF1-deficient malignancies. Specifically, we evaluated primary human NF1-deficient peripheral nervous system tumors and found that MNKs are activated in the majority of tumors tested. Genetic and chemical suppression of MNKs in NF1-deficient murine tumor models and human cell lines potently cooperated with MEK inhibitors to kill these cancers through effects on eIF4E. We also demonstrated that MNK kinases are important and direct targets of cabozantinib. Accordingly, coadministration of cabozantinib and MEK inhibitors triggered dramatic regression in an aggressive genetically engineered tumor model. The cytotoxicity of this combination required the suppression of MNK-induced eIF4E phosphorylation and was not recapitulated by suppressing other cabozantinib targets. Collectively, these studies demonstrate that combined MNK and MEK suppression represents a promising therapeutic strategy for these incurable Ras-driven tumors and highlight the utility of developing selective MNK inhibitors for these and possibly other malignancies.
Assuntos
MAP Quinase Quinase Quinases/antagonistas & inibidores , Mutação , Neoplasias de Bainha Neural/tratamento farmacológico , Neoplasias de Bainha Neural/genética , Neurofibromina 1/genética , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Anilidas/administração & dosagem , Animais , Linhagem Celular Tumoral , Genes da Neurofibromatose 1 , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Complexos Multiproteicos/metabolismo , Neoplasias de Bainha Neural/metabolismo , Proteínas de Transporte Nucleocitoplasmático/antagonistas & inibidores , Fosforilação , Inibidores de Proteínas Quinases/administração & dosagem , Piridinas/administração & dosagem , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
There is a lack of effective predictive biomarkers to precisely assign optimal therapy to cancer patients. While most efforts are directed at inferring drug response phenotype based on genotype, there is very focused and useful phenotypic information to be gained from directly perturbing the patient's living cancer cell with the drug(s) in question. To satisfy this unmet need, we developed the Dynamic BH3 Profiling technique to measure early changes in net pro-apoptotic signaling at the mitochondrion ("priming") induced by chemotherapeutic agents in cancer cells, not requiring prolonged ex vivo culture. We find in cell line and clinical experiments that early drug-induced death signaling measured by Dynamic BH3 Profiling predicts chemotherapy response across many cancer types and many agents, including combinations of chemotherapies. We propose that Dynamic BH3 Profiling can be used as a broadly applicable predictive biomarker to predict cytotoxic response of cancers to chemotherapeutics in vivo.
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Morte Celular , Neoplasias/tratamento farmacológico , Transdução de Sinais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Feminino , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Mitocôndrias/metabolismo , Neoplasias/patologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Medicina de PrecisãoRESUMO
UNLABELLED: NF1 encodes a RAS GTPase-activating protein. Accordingly, aberrant RAS activation underlies the pathogenesis of NF1-mutant cancers. Nevertheless, it is unclear which RAS pathway components represent optimal therapeutic targets. Here, we identify mTORC1 as the key PI3K effector in NF1-mutant nervous system malignancies and conversely show that mTORC2 and AKT are dispensable. However, we find that tumor regression requires sustained inhibition of both mTORC1 and MEK. Transcriptional profiling studies were therefore used to establish a signature of effective mTORC1-MEK inhibition in vivo. We unexpectedly found that the glucose transporter GLUT1 was potently suppressed, but only when both pathways were inhibited. Moreover, unlike VHL- and LKB1-mutant cancers, reduction of (18)F-FDG uptake required the suppression of both mTORC1 and MEK. Together, these studies identify optimal and suboptimal therapeutic targets in NF1-mutant malignancies and define a noninvasive means of measuring combined mTORC1-MEK inhibition in vivo, which can be readily incorporated into clinical trials. SIGNIFICANCE: This work demonstrates that mTORC1 and MEK are key therapeutic targets in NF1-mutant cancers and establishes a noninvasive biomarker of effective, combined target inhibition that can be evaluated in clinical trials.
Assuntos
Neoplasias/genética , Neoplasias/metabolismo , Neurofibromina 1/genética , Transdução de Sinais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biomarcadores/metabolismo , Classe Ia de Fosfatidilinositol 3-Quinase/metabolismo , Fluordesoxiglucose F18/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Terapia de Alvo Molecular , Complexos Multiproteicos/metabolismo , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Neoplasias de Tecido Nervoso/diagnóstico , Neoplasias de Tecido Nervoso/tratamento farmacológico , Neoplasias de Tecido Nervoso/genética , Neoplasias de Tecido Nervoso/metabolismo , Neoplasias de Bainha Neural/diagnóstico , Neoplasias de Bainha Neural/tratamento farmacológico , Neoplasias de Bainha Neural/genética , Neoplasias de Bainha Neural/metabolismo , Neurofibromina 1/metabolismo , Tomografia por Emissão de Pósitrons , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismoRESUMO
Although the majority of patients with EGFR-mutant lung cancer respond well to EGF receptor (EGFR) tyrosine kinase inhibitors (TKI), all patients eventually develop resistance. The mechanism of acquired resistance is still unknown for a considerable subset of cases. This study reveals the NF1 tumor suppressor gene as a new mediator of resistance to EGFR TKIs and provides a mechanistic rationale for developing combination therapies.
Assuntos
Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/tratamento farmacológico , Neurofibromina 1/genética , Inibidores de Proteínas Quinases/uso terapêutico , Antineoplásicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/genética , Mutação , Inibidores de Proteínas Quinases/farmacologiaRESUMO
The RAS pathway is one of the most commonly deregulated pathways in human cancer. Mutations in RAS genes occur in nearly 30% of all human tumors. However in some tumor types RAS mutations are conspicuously absent or rare, despite the fact that RAS and downstream effector pathways are hyperactivated. Recently, RAS GTPase Activating Proteins (RAS GAPs) have emerged as an expanding class of tumor suppressors that, when inactivated, provide an alternative mechanism of activating RAS. RAS GAPs normally turn off RAS by catalyzing the hydrolysis of RAS-GTP. As such, the loss of a RAS GAP would be expected to promote excessive RAS activation. Indeed, this is the case for the NF1 gene, which plays an established role in a familial tumor predisposition syndrome and a variety of sporadic cancers. However, there are 13 additional RAS GAP family members in the human genome. We are only now beginning to understand why there are so many RAS GAPs, how they differentially function, and what their potential role(s) in human cancer are. This review will focus on our current understanding of RAS GAPs in human disease and will highlight important outstanding questions.
Assuntos
Neoplasias/genética , Neoplasias/metabolismo , Proteínas Ativadoras de ras GTPase/fisiologia , Proteínas de Transporte/fisiologia , Resistencia a Medicamentos Antineoplásicos , Proteínas Ativadoras de GTPase/fisiologia , Genes da Neurofibromatose 1/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Humanos , Neurofibromina 1/fisiologia , Proteínas Supressoras de Tumor/fisiologia , Proteínas Ativadoras de ras GTPase/genéticaRESUMO
BRAF mutations play a well-established role in melanomagenesis; however, without additional genetic alterations, tumor development is restricted by oncogene-induced senescence (OIS). Here, we show that mutations in the NF1 tumor suppressor gene cooperate with BRAF mutations in melanomagenesis by preventing OIS. In a genetically engineered mouse model, Nf1 mutations suppress Braf-induced senescence, promote melanocyte hyperproliferation, and enhance melanoma development. Nf1 mutations function by deregulating both phosphoinositide 3-kinase and extracellular signal-regulated kinase pathways. As such, Nf1/Braf-mutant tumors are resistant to BRAF inhibitors but are sensitive to combined inhibition of mitogen-activated protein/extracellular signal-regulated kinase kinase and mTOR. Importantly, NF1 is mutated or suppressed in human melanomas that harbor concurrent BRAF mutations, NF1 ablation decreases the sensitivity of melanoma cell lines to BRAF inhibitors, and NF1 is lost in tumors from patients following treatment with these agents. Collectively, these studies provide mechanistic insight into how NF1 cooperates with BRAF mutations in melanoma and show that NF1/neurofibromin inactivation may have an impact on responses to targeted therapies.
Assuntos
Carcinogênese/genética , Genes da Neurofibromatose 1 , Melanoma/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Animais , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Genótipo , Humanos , Indóis/farmacologia , Melanócitos/patologia , Melanócitos/fisiologia , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Camundongos Nus , Neurofibromina 1/deficiência , Neurofibromina 1/genética , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Transdução de Sinais , Sulfonamidas/farmacologia , Vemurafenib , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here, we show, in multiple complementary models, that resistance to WZ4002 develops through aberrant activation of extracellular signal-regulated kinase (ERK) signaling caused by either an amplification of mitogen-activated protein kinase 1 (MAPK1) or by downregulation of negative regulators of ERK signaling. Inhibition of MAP-ERK kinase (MEK) or ERK restores sensitivity to WZ4002 and prevents the emergence of drug resistance. We further identify MAPK1 amplification in an erlotinib-resistant EGFR-mutant non-small cell lung carcinoma patient. In addition, the WZ4002-resistant MAPK1-amplified cells also show an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials.
Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Acrilamidas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Proliferação de Células , Receptores ErbB/genética , Cloridrato de Erlotinib , Gefitinibe , Humanos , Neoplasias Pulmonares/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Terapia de Alvo Molecular , Mutação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/biossíntese , Receptor ErbB-2/genéticaRESUMO
Ras-driven tumors are often refractory to conventional therapies. Here we identify a promising targeted therapeutic strategy for two Ras-driven cancers: Nf1-deficient malignancies and Kras/p53 mutant lung cancer. We show that agents that enhance proteotoxic stress, including the HSP90 inhibitor IPI-504, induce tumor regression in aggressive mouse models, but only when combined with rapamycin. These agents synergize by promoting irresolvable ER stress, resulting in catastrophic ER and mitochondrial damage. This process is fueled by oxidative stress, which is caused by IPI-504-dependent production of reactive oxygen species, and the rapamycin-dependent suppression of glutathione, an important endogenous antioxidant. Notably, the mechanism by which these agents cooperate reveals a therapeutic paradigm that can be expanded to develop additional combinations.
Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzoquinonas/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Lactamas Macrocíclicas/farmacologia , Neoplasias de Bainha Neural/tratamento farmacológico , Sirolimo/farmacologia , Proteínas ras/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Imunofluorescência , Glutationa/antagonistas & inibidores , Glutationa/biossíntese , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Marcação In Situ das Extremidades Cortadas , Camundongos , Mitocôndrias/efeitos dos fármacos , Terapia de Alvo Molecular , Neoplasias de Bainha Neural/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Interferência de RNA , RNA Interferente Pequeno , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo , eIF-2 Quinase/antagonistas & inibidores , eIF-2 Quinase/genéticaRESUMO
Neurofibromatosis type 1 (NF1) is a common disorder that arises secondary to mutations in the tumor suppressor gene NF1. Glomus tumors are small, benign but painful tumors that originate from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. We report 11 individuals with NF1 who harbored 20 glomus tumors of the fingers and 1 in the toe; 5 individuals had multiple glomus tumors. We hypothesized that biallelic inactivation of NF1 underlies the pathogenesis of these tumors. In 12 NF1-associated glomus tumors, we used cell culture and laser capture microdissection to isolate DNA. We also analyzed two sporadic (not NF1-associated) glomus tumors. Genetic analysis showed germ line and somatic NF1 mutations in seven tumors. RAS mitogen-activated protein kinase hyperactivation was observed in cultured NF1(-/-) glomus cells, reflecting a lack of inhibition of the pathway by functional neurofibromin, the protein product of NF1. No abnormalities in NF1 or RAS mitogen-activated protein kinase activation were found in sporadic glomus tumors. By comparative genomic hybridization, we observed amplification of the 3'-end of CRTAC1 and a deletion of the 5'-end of WASF1 in two NF1-associated glomus tumors. For the first time, we show that loss of neurofibromin function is crucial in the pathogenesis of glomus tumors in NF1. Glomus tumors of the fingers or toes should be considered as part of the tumor spectrum of NF1.