RESUMO
Small-molecule kinase inhibitors represent a major group of cancer therapeutics, but tumor responses are often incomplete. To identify pathways that modulate kinase inhibitor response, we conducted a genome-wide knockout (KO) screen in glioblastoma cells treated with the pan-ErbB inhibitor neratinib. Loss of general control nonderepressible 2 (GCN2) kinase rendered cells resistant to neratinib, whereas depletion of the GADD34 phosphatase increased neratinib sensitivity. Loss of GCN2 conferred neratinib resistance by preventing binding and activation of GCN2 by neratinib. Several other Food and Drug Administration (FDA)-approved inhibitors, such erlotinib and sunitinib, also bound and activated GCN2. Our results highlight the utility of genome-wide functional screens to uncover novel mechanisms of drug action and document the role of the integrated stress response (ISR) in modulating the response to inhibitors of oncogenic kinases.
Assuntos
Trifosfato de Adenosina/metabolismo , Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Quinolinas/farmacologia , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Deleção de Genes , Glioblastoma/tratamento farmacológico , Humanos , Inibidores de Proteínas Quinases/químicaRESUMO
Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor-associated protein CD79B. CD79B-mutant PCNSLs showed enrichment of mammalian target of rapamycin (mTOR)-related gene sets and increased staining with PI3K/mTOR activation markers. Inhibition of the PI3K isoforms p110α/p110δ or mTOR synergized with ibrutinib to induce cell death in CD79B-mutant PCNSL cells.Significance: Ibrutinib has substantial activity in patients with relapsed or refractory B-cell lymphoma of the CNS. Response rates in PCNSL were considerably higher than reported for diffuse large B-cell lymphoma outside the CNS, suggesting a divergent molecular pathogenesis. Combined inhibition of BTK and PI3K/mTOR may augment the ibrutinib response in CD79B-mutant human PCNSLs. Cancer Discov; 7(9); 1018-29. ©2017 AACR.See related commentary by Lakshmanan and Byrd, p. 940This article is highlighted in the In This Issue feature, p. 920.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Linfoma de Células B/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Adenina/análogos & derivados , Adulto , Tirosina Quinase da Agamaglobulinemia , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Proteínas Adaptadoras de Sinalização CARD/genética , Neoplasias do Sistema Nervoso Central/sangue , Neoplasias do Sistema Nervoso Central/líquido cefalorraquidiano , Neoplasias do Sistema Nervoso Central/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Guanilato Ciclase/genética , Humanos , Linfoma de Células B/sangue , Linfoma de Células B/líquido cefalorraquidiano , Linfoma de Células B/metabolismo , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Mutação , Piperidinas , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirazóis/efeitos adversos , Pirazóis/farmacocinética , Pirimidinas/efeitos adversos , Pirimidinas/farmacocinética , Resultado do Tratamento , Adulto JovemRESUMO
IDH1 and IDH2 are homodimeric enzymes that catalyze the conversion of isocitrate to α-ketoglutarate (α-KG) and concomitantly produce reduced NADPH from NADP(+) Mutations in the genes encoding IDH1 and IDH2 have recently been found in a variety of human cancers, most commonly glioma, acute myeloid leukemia (AML), chondrosarcoma, and intrahepatic cholangiocarcinoma. The mutant protein loses its normal enzymatic activity and gains a new ability to produce the "oncometabolite" R(-)-2-hydroxyglutarate (R-2-HG). R-2-HG competitively inhibits α-KG-dependent enzymes which play crucial roles in gene regulation and tissue homeostasis. Expression of mutant IDH impairs cellular differentiation in various cell lineages and promotes tumor development in cooperation with other cancer genes. First-generation inhibitors of mutant IDH have entered clinical trials, and have shown encouraging results in patients with IDH-mutant AML. This article summarizes recent progress in our understanding of the role of mutant IDH in tumorigenesis.Clin Cancer Res; 22(8); 1837-42. ©2016 AACR.
Assuntos
Isocitrato Desidrogenase/genética , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Transdução de Sinais , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Transformação Celular Neoplásica , Humanos , Isocitrato Desidrogenase/antagonistas & inibidores , Isocitrato Desidrogenase/metabolismo , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Pesquisa Translacional BiomédicaRESUMO
In a wide range of neuroblastoma-derived lines oxovanadium compounds such as bis(maltolato)oxovanadium(IV) (BMOV) are cytotoxic. This is not explained by oxidative stress or inhibition of ion channels. Genotoxicity is unlikely given that a p53 response is absent and p53-mutant lines are also sensitive. Cytotoxicity is inhibited by N-acetyl cysteine and glutathione ester, indicating that BMOV action is sensitive to cytoplasmic redox and thiol status. Significantly, combining BMOV with glutathione synthesis inhibition greatly enhances BMOV-induced cell death. This combination treatment triggers high AKT pathway activation, highlighting the potential functional importance of PTP inhibition by BMOV. AKT activation itself, however, is not required for cytotoxicity. Oxovanadium compounds may thus represent novel leads as p53-independent therapeutics for neuroblastoma.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Butionina Sulfoximina/farmacologia , Neuroblastoma/tratamento farmacológico , Pironas/farmacologia , Vanadatos/farmacologia , Animais , Butionina Sulfoximina/administração & dosagem , Linhagem Celular Tumoral , Sinergismo Farmacológico , Fibroblastos/efeitos dos fármacos , Humanos , Camundongos , Neuroblastoma/metabolismo , Oxirredução , Pironas/administração & dosagem , Transdução de Sinais , Transfecção , Vanadatos/administração & dosagemRESUMO
The recent discovery of mutations in metabolic enzymes has rekindled interest in harnessing the altered metabolism of cancer cells for cancer therapy. One potential drug target is isocitrate dehydrogenase 1 (IDH1), which is mutated in multiple human cancers. Here, we examine the role of mutant IDH1 in fully transformed cells with endogenous IDH1 mutations. A selective R132H-IDH1 inhibitor (AGI-5198) identified through a high-throughput screen blocked, in a dose-dependent manner, the ability of the mutant enzyme (mIDH1) to produce R-2-hydroxyglutarate (R-2HG). Under conditions of near-complete R-2HG inhibition, the mIDH1 inhibitor induced demethylation of histone H3K9me3 and expression of genes associated with gliogenic differentiation. Blockade of mIDH1 impaired the growth of IDH1-mutant--but not IDH1-wild-type--glioma cells without appreciable changes in genome-wide DNA methylation. These data suggest that mIDH1 may promote glioma growth through mechanisms beyond its well-characterized epigenetic effects.
Assuntos
Benzenoacetamidas/farmacologia , Diferenciação Celular , Inibidores Enzimáticos/farmacologia , Glioma/enzimologia , Glioma/patologia , Imidazóis/farmacologia , Isocitrato Desidrogenase/antagonistas & inibidores , Isocitrato Desidrogenase/genética , Animais , Benzenoacetamidas/administração & dosagem , Benzenoacetamidas/toxicidade , Diferenciação Celular/efeitos dos fármacos , Transformação Celular Neoplásica , Inibidores Enzimáticos/toxicidade , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/tratamento farmacológico , Glioma/genética , Glutaratos/metabolismo , Histonas/metabolismo , Imidazóis/administração & dosagem , Imidazóis/toxicidade , Isocitrato Desidrogenase/química , Isocitrato Desidrogenase/metabolismo , Metilação , Camundongos , Camundongos SCID , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Multimerização Proteica , Interferência de RNA , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Retinoic acid (RA)-induced differentiation therapy is partially successful in neuroblastoma treatment. We found that a novel combination of vanadium-based PTP inhibitors with RA induced extensive differentiation in neuroblastoma cells. In contrast to RA alone, this led to either permanent differentiation or senescence after 14days of combined treatment followed by chemical removal. Senescence was dependent in part on synergistic AKT and ERK activation. p21 was also strongly induced, but in contrast to oncogene-induced senescence, p53 was not activated. Vanadium-based inhibitors thus serve strongly to enhance RA's ability to drive differentiation and a novel form of senescence in neuroblastoma cells.