RESUMO
BACKGROUND: No biomarkers have been established to predict treatment efficacy in renal cell carcinoma (RCC). In an exploratory retrospective analysis of a Phase 2 study, we constructed composite biomarker scores (CBSs) to predict progression-free survival (PFS) and overall survival (OS) in patients with metastatic RCC randomised to receive lenvatinib-plus-everolimus. METHODS: Of 40 biomarkers tested, the 5 most strongly associated with PFS (HGF, MIG, IL-18BP, IL-18, ANG-2) or OS (TIMP-1, M-CSF, IL-18BP, ANG-2, VEGF) were used to make a 5-factor PFS-CBS or OS-CBS, respectively. A 2-factor CBS was generated with biomarkers common to PFS-CBS and OS-CBS. Patients were divided into groups accordingly (5-factor-CBS high: 3-5, CBS-low: 0-2; 2-factor-CBS high: 1-2, CBS-low: 0). RESULTS: PFS/OS with lenvatinib-plus-everolimus were significantly longer in the 5-factor CBS-high group versus the CBS-low group (P = 0.0022/P < 0.0001, respectively). In the CBS-high group, PFS/OS were significantly longer with lenvatinib-plus-everolimus versus everolimus (P < 0.001/P = 0.0079, respectively); PFS was also significantly longer with lenvatinib-plus-everolimus versus lenvatinib (P = 0.0046). The 5-factor-CBS had a predictive role in PFS and OS after multivariate analysis. Similar trends were observed with the 2-factor-CBS for PFS (i.e., lenvatinib-plus-everolimus versus everolimus). CONCLUSIONS: The 5-factor CBS may identify patients with metastatic RCC who would benefit from lenvatinib-plus-everolimus versus everolimus; additional validation is required. CLINICAL TRIAL REGISTRATION: The clinical trial registration number is NCT01136733.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/sangue , Carcinoma de Células Renais/sangue , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/sangue , Neoplasias Renais/tratamento farmacológico , Adulto , Idoso , Carcinoma de Células Renais/mortalidade , Everolimo/administração & dosagem , Feminino , Humanos , Neoplasias Renais/mortalidade , Masculino , Pessoa de Meia-Idade , Compostos de Fenilureia/administração & dosagem , Intervalo Livre de Progressão , Quinolinas/administração & dosagem , Resultado do TratamentoRESUMO
Target-protein degradation is an emerging field in drug discovery and development. In particular, the substrate-receptor proteins of the cullin-ubiquitin ligase system play a key role in selective protein degradation, which is an essential component of the anti-myeloma activity of immunomodulatory drugs (IMiDs), such as lenalidomide. Here, we demonstrate that a series of anticancer sulfonamides NSC 719239 (E7820), indisulam, and NSC 339004 (chloroquinoxaline sulfonamide, CQS) induce proteasomal degradation of the U2AF-related splicing factor coactivator of activating protein-1 and estrogen receptors (CAPERα) via CRL4DCAF15 mediated ubiquitination in human cancer cell lines. Both CRISPR-Cas9-based knockout of DCAF15 and a single amino acid substitution of CAPERα conferred resistance against sulfonamide-induced CAPERα degradation and cell-growth inhibition. Thus, these sulfonamides represent selective chemical probes for disrupting CAPERα function and designate DCAFs as promising drug targets for promoting selective protein degradation in cancer therapy.
Assuntos
Indóis/farmacologia , Proteínas Nucleares/metabolismo , Splicing de RNA , Proteínas de Ligação a RNA/metabolismo , Sulfonamidas/metabolismo , Antineoplásicos/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Proteínas Nucleares/química , Proteínas Nucleares/genética , Proteólise/efeitos dos fármacos , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Sulfonamidas/farmacologiaRESUMO
BACKGROUND: Lenvatinib plus pembrolizumab demonstrated clinically meaningful benefit in patients with previously treated advanced endometrial carcinoma in Study 111/KEYNOTE-146 (NCT02501096). In these exploratory analyses from this study, we evaluated the associations between clinical outcomes and gene expression signature scores and descriptively summarized response in biomarker subpopulations defined by tumor mutational burden (TMB) and DNA variants for individual genes of interest. METHODS: Patients with histologically confirmed metastatic endometrial carcinoma received oral lenvatinib 20 mg once daily plus intravenous pembrolizumab 200 mg every 3 weeks for 35 cycles. Archived formalin-fixed paraffin-embedded tissue was obtained from all patients. T-cell-inflamed gene expression profile (TcellinfGEP) and 11 other gene signatures were evaluated by RNA sequencing. TMB, hotspot mutations in PIK3CA (oncogene), and deleterious mutations in PTEN and TP53 (tumor suppressor genes) were evaluated by whole-exome sequencing (WES). RESULTS: 93 and 79 patients were included in the RNA-sequencing-evaluable and WES-evaluable populations, respectively. No statistically significant associations were observed between any of the RNA-sequencing signature scores and objective response rate or progression-free survival. Area under the receiver operating characteristic curve values for response ranged from 0.39 to 0.54; all 95% CIs included 0.50. Responses were seen regardless of TMB (≥175 or <175 mutations/exome) and mutation status. There were no correlations between TcellinfGEP and TMB, TcellinfGEP and microvessel density (MVD), or MVD and TMB. CONCLUSIONS: This analysis demonstrated efficacy for lenvatinib plus pembrolizumab regardless of biomarker status. Results from this study do not support clinical utility of the evaluated biomarkers. Further investigation of biomarkers for this regimen is warranted. TRIAL REGISTRATION NUMBER: NCT02501096.
Assuntos
Anticorpos Monoclonais Humanizados , Neoplasias do Endométrio , Compostos de Fenilureia , Quinolinas , Feminino , Humanos , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/genética , Biomarcadores Tumorais/genética , RNA/uso terapêuticoRESUMO
Endothelial Notch signaling is critical for tumor angiogenesis. Notch1 blockade can interfere with tumor vessel function but causes tissue hypoxia and gastrointestinal toxicity. Notch4 is primarily expressed in endothelial cells, where it may promote angiogenesis; however, effective therapeutic targeting of Notch4 has not been successful. We developed highly specific Notch4-blocking antibodies, 6-3-A6 and humanized E7011, allowing therapeutic targeting of Notch4 to be assessed in tumor models. Notch4 was expressed in tumor endothelial cells in multiple cancer models, and endothelial expression was associated with response to E7011/6-3-A6. Anti-Notch4 treatment significantly delayed tumor growth in mouse models of breast, skin, and lung cancers. Enhanced tumor inhibition occurred when anti-Notch4 treatment was used in combination with chemotherapeutics. Endothelial transcriptomic analysis of murine breast tumors treated with 6-3-A6 identified significant changes in pathways of vascular function but caused only modest change in canonical Notch signaling. Analysis of early and late treatment timepoints revealed significant differences in vessel area and perfusion in response to anti-Notch4 treatment. We conclude that targeting Notch4 improves tumor growth control through endothelial intrinsic mechanisms. SIGNIFICANCE: A first-in-class anti-Notch4 agent, E7011, demonstrates strong antitumor effects in murine tumor models including breast carcinoma. Endothelial Notch4 blockade reduces perfusion and vessel area.
Assuntos
Anticorpos Neutralizantes , Neovascularização Patológica , Receptor Notch4 , Animais , Receptor Notch4/metabolismo , Camundongos , Humanos , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Neovascularização Patológica/metabolismo , Feminino , Anticorpos Neutralizantes/farmacologia , Anticorpos Neutralizantes/uso terapêutico , Linhagem Celular Tumoral , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Proliferação de Células/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismoRESUMO
Eribulin is a microtubule dynamics inhibitor with tumor microenvironment modulation activity such as vascular remodeling activity. Here, we investigated antitumor and immunomodulatory activities of eribulin and its liposomal formulation (eribulin-LF) as monotherapies or in combination with anti-programmed death 1 (PD-1) Ab. The antitumor activity of eribulin or eribulin-LF as monotherapy or in combination with anti-PD-1 Ab was examined in a P-glycoprotein-knockout 4T1 model. Eribulin and eribulin-LF showed stronger antitumor activity in immunocompetent mice compared with immunodeficient mice, indicating that they have immunomodulatory activity that underlies its antitumor activity. Combination therapy of eribulin and eribulin-LF with anti-PD-1 Ab showed antitumor activity, and the combination activity of eribulin-LF with anti-PD-1 Ab was observed at a lower dose and longer interval of administration compared with that using eribulin. To examine the immunomodulatory activity of eribulin and eribulin-LF and its underlying mechanisms, we performed flow cytometry, IHC, and gene expression profiling. IHC and flow cytometry revealed that eribulin-LF increased microvessel density and intratumoral populations of cytotoxic T cells and natural killer cells rather than eribulin. Gene expression profiling demonstrated that eribulin-LF induces IFNγ signaling. Furthermore, IHC also showed that eribulin-LF increased infiltration of CD8-positive cells together with increased CD31-positive cells. Eribulin-LF also increased ICAM-1 expression, which is essential for lymphocyte adhesion to vascular endothelial cells. In conclusion, eribulin showed combination antitumor activity with anti-PD-1 Ab via immunomodulation due to its vascular remodeling activity, and the liposomal formulation showed improved antitumor activity over the standard formulation.
Assuntos
Lipossomos , Remodelação Vascular , Animais , Camundongos , Células Endoteliais , Linhagem Celular TumoralRESUMO
PURPOSE: Combination treatment using lenvatinib (a multikinase inhibitor) plus pembrolizumab (a programmed death-1 immune checkpoint inhibitor) has shown efficacy in the treatment of endometrial and renal cell cancers. This phase 1b study investigated the tolerability and safety of lenvatinib plus pembrolizumab in Japanese patients with metastatic selected solid tumors. METHODS: Patients received a starting dose of 20 mg oral lenvatinib per day plus 200 mg intravenous pembrolizumab every 3 weeks in 21-day cycles. Dose-limiting toxicities were evaluated during the first cycle. Tumor assessments were performed by investigators based on modified RECIST v1.1. Pharmacokinetic parameters and serum biomarkers were assessed. RESULTS: Among enrolled patients (N = 6), 3 had non-small cell lung cancer, and 3 had urothelial cancer. No patients experienced a dose-limiting toxicity. All patients experienced at least 1 treatment-related treatment-emergent adverse event. The objective response rate was 33.3% (95% confidence interval 4.3-77.7); both responses (1 complete, 1 partial) were observed in patients with urothelial cancer. Pharmacokinetics were consistent with previous studies. Serum angiopoietin-2 levels tended to decrease, and serum fibroblast growth factor-23 levels tended to increase from baseline to Cycle 2 Day 1. CONCLUSIONS: This study supports the tolerability of 20 mg lenvatinib/day plus 200 mg pembrolizumab every 3 weeks in Japanese patients, consistent with the results from a global study of lenvatinib plus pembrolizumab combination therapy in patients with selected solid tumors. Favorable antitumor activity was observed and there were no new safety signals identified. TRIAL REGISTRATION: Clinical Trials.gov number: NCT03006887.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células de Transição , Neoplasias Renais , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Estudos de Viabilidade , Japão , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma de Células de Transição/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversosRESUMO
STAT transcription factors are tyrosine phosphorylated upon cytokine stimulation and enter the nucleus to activate target genes. We show that Rac1 and a GTPase-activating protein, MgcRacGAP, bind directly to p-STAT5A and are required to promote its nuclear translocation. Using permeabilized cells, we find that nuclear translocation of purified p-STAT5A is dependent on the addition of GTP-bound Rac1, MgcRacGAP, importin alpha, and importin beta. p-STAT3 also enters the nucleus via this transport machinery, and mutant STATs lacking the MgcRacGAP binding site do not enter the nucleus even after phosphorylation. We conclude that GTP-bound Rac1 and MgcRacGAP function as a nuclear transport chaperone for activated STATs.
Assuntos
Núcleo Celular/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Transporte Proteico , Fator de Transcrição STAT5/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Animais , Western Blotting , Linhagem Celular , Humanos , Imunoprecipitação , Camundongos , Fosforilação , Tirosina/metabolismo , alfa Carioferinas/metabolismo , beta Carioferinas/metabolismoRESUMO
Immune checkpoint blockade (ICB) therapy has substantially improved the outcomes of patients with many types of cancers, including renal cell carcinoma (RCC). Initially studied as monotherapy, immunotherapy-based combination regimens have improved the clinical benefit achieved by ICB monotherapy and have revolutionized RCC treatment. While biomarkers like PD-L1 and tumor mutational burden (TMB) are FDA approved as biomarkers for ICB monotherapy, there are no known biomarkers for combination immunotherapies. Here, we describe the clinical outcomes and genomic determinants of response from a phase Ib/II clinical trial on patients with advanced RCC evaluating the efficacy of lenvatinib, a multi-kinase inhibitor mainly targeting VEGFR and FGFR plus pembrolizumab, an anti-PD1 immunotherapy. Concurrent treatment with lenvatinib and pembrolizumab resulted in an objective response rate of 79% (19/24) and tumor shrinkage in 96% (23/24) of patients. While tumor mutational burden (TMB) did not predict for clinical benefit, germline HLA-I diversity strongly impacted treatment efficacy. Specifically, HLA-I evolutionary divergence (HED), which measures the breadth of a patient's immunopeptidome, was associated with both improved clinical benefit and durability of response. Our results identify lenvatinib plus pembrolizumab as a highly active treatment strategy in RCC and reveal HLA-I diversity as a critical determinant of efficacy for this combination. HED also predicted better survival in a separate cohort of patients with RCC following therapy with anti-PD-1-based combination therapy. IMPLICATIONS: These findings have substantial implications for RCC therapy and for understanding immunogenetic mechanisms of efficacy and warrants further investigation.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/patologia , Variação Genética , Antígenos HLA/genética , Neoplasias Renais/patologia , Idoso , Anticorpos Monoclonais Humanizados/administração & dosagem , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/genética , Feminino , Seguimentos , Humanos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Masculino , Pessoa de Meia-Idade , Compostos de Fenilureia/administração & dosagem , Prognóstico , Quinolinas/administração & dosagem , Taxa de SobrevidaRESUMO
PURPOSE: In REFLECT, lenvatinib demonstrated an effect on overall survival (OS) by confirmation of noninferiority to sorafenib in unresectable hepatocellular carcinoma. This analysis assessed correlations between serum or tissue biomarkers and efficacy outcomes from REFLECT. EXPERIMENTAL DESIGN: Serum biomarkers (VEGF, ANG2, FGF19, FGF21, and FGF23) were measured by ELISA. Gene expression in tumor tissues was measured by the nCounter PanCancer Pathways Panel. Pharmacodynamic changes in serum biomarker levels from baseline, and associations of clinical outcomes with baseline biomarker levels, were evaluated. RESULTS: Four hundred and seven patients were included in the serum analysis set (lenvatinib n = 279, sorafenib n = 128); 58 patients were included in the gene-expression analysis set (lenvatinib n = 34, sorafenib n = 24). Both treatments were associated with increases in VEGF; only lenvatinib was associated with increases in FGF19 and FGF23 at all time points. Lenvatinib-treated responders had greater increases in FGF19 and FGF23 versus nonresponders at cycle 4, day 1 (FGF19: 55.2% vs. 18.3%, P = 0.014; FGF23: 48.4% vs. 16.4%, P = 0.0022, respectively). Higher baseline VEGF, ANG2, and FGF21 correlated with shorter OS in both treatment groups. OS was longer for lenvatinib than sorafenib [median, 10.9 vs. 6.8 months, respectively; HR, 0.53; 95% confidence interval (CI), 0.33-0.85; P-interaction = 0.0397] with higher baseline FGF21. In tumor tissue biomarker analysis, VEGF/FGF-enriched groups showed improved OS with lenvatinib versus the intermediate VEGF/FGF group (HR, 0.39; 95% CI, 0.16-0.91; P = 0.0253). CONCLUSIONS: Higher baseline levels of VEGF, FGF21, and ANG2 may be prognostic for shorter OS. Higher baseline FGF21 may be predictive for longer OS with lenvatinib compared with sorafenib, but this needs confirmation.
Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/análise , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/mortalidade , Compostos de Fenilureia/uso terapêutico , Quinolinas/uso terapêutico , Sorafenibe/uso terapêutico , Biomarcadores Tumorais/farmacocinética , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/química , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/química , Valor Preditivo dos Testes , Taxa de SobrevidaRESUMO
Anti-vascular endothelial growth factor (VEGF) therapy shows antitumor activity against various types of solid cancers. Several resistance mechanisms against anti-VEGF therapy have been elucidated; however, little is known about the mechanisms by which the acquired resistance arises. Here, we developed new anti-VEGF therapy-resistant models driven by chronic expression of the mouse VEGFR2 extracellular domain fused with the human IgG4 fragment crystallizable (Fc) region (VEGFR2-Fc). In the VEGFR2-Fc-expressing resistant tumors, we demonstrated that the FGFR2 signaling pathway was activated, and pericytes expressing high levels of FGF2 were co-localized with endothelial cells. Lenvatinib, a multiple tyrosine kinase inhibitor including VEGFR and FGFR inhibition, showed marked antitumor activity against VEGFR2-Fc-expressing resistant tumors accompanied with a decrease in the area of tumor vessels and suppression of phospho-FGFR2 in tumors. Our findings reveal the key role that intercellular FGF2 signaling between pericytes and endothelial cells plays in maintaining the tumor vasculature in anti-VEGF therapy-resistant tumors.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Fator 2 de Crescimento de Fibroblastos/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Transdução de Sinais , Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Feminino , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Melanoma Experimental/irrigação sanguínea , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Camundongos , Modelos Biológicos , Pericitos/efeitos dos fármacos , Pericitos/metabolismo , Compostos de Fenilureia/farmacologia , Compostos de Fenilureia/uso terapêutico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Cell division is finely controlled by various molecules including small G proteins and kinases/phosphatases. Among these, Aurora B, RhoA, and the GAP MgcRacGAP have been implicated in cytokinesis, but their underlying mechanisms of action have remained unclear. Here, we show that MgcRacGAP colocalizes with Aurora B and RhoA, but not Rac1/Cdc42, at the midbody. We also report that Aurora B phosphorylates MgcRacGAP on serine residues and that this modification induces latent GAP activity toward RhoA in vitro. Expression of a kinase-defective mutant of Aurora B disrupts cytokinesis and inhibits phosphorylation of MgcRacGAP at Ser387, but not its localization to the midbody. Overexpression of a phosphorylation-deficient MgcRacGAP-S387A mutant, but not phosphorylation-mimic MgcRacGAP-S387D mutant, arrests cytokinesis at a late stage and induces polyploidy. Together, these findings indicate that during cytokinesis, MgcRacGAP, previously known as a GAP for Rac/Cdc42, is functionally converted to a RhoGAP through phosphorylation by Aurora B.
Assuntos
Divisão Celular/genética , Células Eucarióticas/enzimologia , Proteínas Ativadoras de GTPase/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Aurora Quinase B , Aurora Quinases , Proteínas Contráteis/genética , Proteínas Contráteis/metabolismo , Proteínas Ativadoras de GTPase/genética , Regulação Enzimológica da Expressão Gênica/genética , Células HeLa , Humanos , Imuno-Histoquímica , Mitose/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Transporte Proteico/genética , Serina/genética , Serina/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
An analysis of secreted proteins by the signal sequence trap method using a cDNA library of the rat pituitary anlage at embryonic days (E) 13.5 revealed the abundant expression of delta-like protein 1 (Dlk1) in the pituitary gland. Dlk1, an epidermal growth factor-like repeat protein in preadipocytes, functions in maintaining the preadipose state. Expression of Dlk1 mRNA in the pituitary at E13.5 and in the adult pituitary was confirmed by in situ hybridization. The expression pattern of Dlk1 during pituitary development was also studied by immunohistochemistry. Dlk1 protein first appeared in Rathke's pouch and the infundibulum at E11.5; as development proceeded, expression became restricted to the pars distalis and pars tuberalis (PT). Dlk1 was expressed in most ACTH cells during the embryonic stages, but its expression was limited to only a few ACTH cells in the adult pituitary. It was also expressed in a small population of TSH, GTH, and PRL cells throughout development, whereas it was present in the cytoplasm of most GH cells at all developmental stages. Similarly, Dlk1 was localized in the cytoplasm of PT cells during development. These findings provide new insights into the mechanism of Dlk1 regarding its regulation of pituitary hormone-secreting cells during development.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana/metabolismo , Hipófise/embriologia , Hipófise/metabolismo , Animais , Embrião de Mamíferos/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular/análise , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/análise , Proteínas de Membrana/genética , RNA Mensageiro/metabolismo , RatosRESUMO
We identified CENP-50 as a novel kinetochore component. We found that CENP-50 is a constitutive component of the centromere that colocalizes with CENP-A and CENP-H throughout the cell cycle in vertebrate cells. To determine the precise role of CENP-50, we examined its role in centromere function by generating a loss-of-function mutant in the chicken DT40 cell line. The CENP-50 knockout was not lethal; however, the growth rate of cells with this mutation was slower than that of wild-type cells. We observed that the time for CENP-50-deficient cells to complete mitosis was longer than that for wild-type cells. Centromeric localization of CENP-50 was abolished in both CENP-H- and CENP-I-deficient cells. Coimmunoprecipitation experiments revealed that CENP-50 interacted with the CENP-H/CENP-I complex in chicken DT40 cells. We also observed severe mitotic defects in CENP-50-deficient cells with apparent premature sister chromatid separation when the mitotic checkpoint was activated, indicating that CENP-50 is required for recovery from spindle damage.
Assuntos
Centrômero/química , Centrômero/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Fuso Acromático/metabolismo , Fuso Acromático/patologia , Sequência de Aminoácidos , Animais , Proteínas de Ciclo Celular , Linhagem Celular , Centrômero/efeitos dos fármacos , Galinhas , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Segregação de Cromossomos/efeitos dos fármacos , Histonas , Humanos , Cinetocoros/química , Cinetocoros/efeitos dos fármacos , Cinetocoros/metabolismo , Mitose/efeitos dos fármacos , Dados de Sequência Molecular , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Mutação/genética , Nocodazol/farmacologia , Proteínas Nucleares , Ligação Proteica , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Fuso Acromático/efeitos dos fármacosRESUMO
Unresectable hepatocellular carcinoma (uHCC) is one of the most lethal and prevalent cancers worldwide, and current systemic therapeutic options for uHCC are limited. Lenvatinib, a multiple receptor tyrosine kinase inhibitor targeting vascular endothelial growth factor receptors (VEGFRs) and fibroblast growth factor receptors (FGFRs), recently demonstrated a treatment effect on overall survival by statistical confirmation of noninferiority to sorafenib in a phase 3 study of uHCC. Here, we investigated mechanisms underlying the antitumor activity of lenvatinib in preclinical HCC models. In vitro proliferation assay of nine human HCC cell lines showed that lenvatinib selectively inhibited proliferation of FGF signal-activated HCC cells including FGF19-expressing Hep3B2.1-7. Lenvatinib suppressed phosphorylation of FRS2, a substrate of FGFR1-4, in these cells in a concentration-dependent manner. Lenvatinib inhibited in vivo tumor growth in Hep3B2.1-7 and SNU-398 xenografts and decreased phosphorylation of FRS2 and Erk1/2 within the tumor tissues. Lenvatinib also exerted antitumor activity and potently reduced tumor microvessel density in PLC/PRF/5 xenograft model and two HCC patient-derived xenograft models. These results suggest that lenvatinib has antitumor activity consistently across diverse HCC models, and that targeting of tumor FGF signaling pathways and anti-angiogenic activity underlies its antitumor activity against HCC tumors.
Assuntos
Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Fatores de Crescimento de Fibroblastos/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neovascularização Patológica/metabolismo , Compostos de Fenilureia/farmacologia , Quinolinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0158888.].
RESUMO
The catalytic activities of covalent and ATP-dependent chromatin remodeling are central to regulating the conformational state of chromatin and the resultant transcriptional output. The enzymes that catalyze these activities are often contained within multiprotein complexes in nature. Two such multiprotein complexes, the polycomb repressive complex 2 (PRC2) methyltransferase and the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeler have been reported to act in opposition to each other during development and homeostasis. An imbalance in their activities induced by mutations/deletions in complex members (e.g. SMARCB1) has been suggested to be a pathogenic mechanism in certain human cancers. Here we show that preclinical models of synovial sarcoma-a cancer characterized by functional SMARCB1 loss via its displacement from the SWI/SNF complex through the pathognomonic SS18-SSX fusion protein-display sensitivity to pharmacologic inhibition of EZH2, the catalytic subunit of PRC2. Treatment with tazemetostat, a clinical-stage, selective and orally bioavailable small-molecule inhibitor of EZH2 enzymatic activity reverses a subset of synovial sarcoma gene expression and results in concentration-dependent cell growth inhibition and cell death specifically in SS18-SSX fusion-positive cells in vitro. Treatment of mice bearing either a cell line or two patient-derived xenograft models of synovial sarcoma leads to dose-dependent tumor growth inhibition with correlative inhibition of trimethylation levels of the EZH2-specific substrate, lysine 27 on histone H3. These data demonstrate a dependency of SS18-SSX-positive, SMARCB1-deficient synovial sarcomas on EZH2 enzymatic activity and suggests the potential utility of EZH2-targeted drugs in these genetically defined cancers.
Assuntos
Antineoplásicos/farmacologia , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Sarcoma Sinovial/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Proteína SMARCB1/genética , Proteína SMARCB1/metabolismo , Sarcoma Sinovial/genética , Sarcoma Sinovial/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The FGFR signaling pathway has a crucial role in proliferation, survival, and migration of cancer cells, tumor angiogenesis, and drug resistance. FGFR genetic abnormalities, such as gene fusion, mutation, and amplification, have been implicated in several types of cancer. Therefore, FGFRs are considered potential targets for cancer therapy. E7090 is an orally available and selective inhibitor of the tyrosine kinase activities of FGFR1, -2, and -3. In kinetic analyses of the interaction between E7090 and FGFR1 tyrosine kinase, E7090 associated more rapidly with FGFR1 than did the type II FGFR1 inhibitor ponatinib, and E7090 dissociated more slowly from FGFR1, with a relatively longer residence time, than did the type I FGFR1 inhibitor AZD4547, suggesting that its kinetics are more similar to the type V inhibitors, such as lenvatinib. E7090 showed selective antiproliferative activity against cancer cell lines harboring FGFR genetic abnormalities and decreased tumor size in a mouse xenograft model using cell lines with dysregulated FGFR Furthermore, E7090 administration significantly prolonged the survival of mice with metastasized tumors in the lung. Our results suggest that E7090 is a promising candidate as a therapeutic agent for the treatment of tumors harboring FGFR genetic abnormalities. It is currently being investigated in a phase I clinical trial. Mol Cancer Ther; 15(11); 2630-9. ©2016 AACR.
Assuntos
Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Inativação Gênica , Humanos , Camundongos , Mortalidade , Mutação , Metástase Neoplásica , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Fosforilação , Inibidores de Proteínas Quinases/química , Interferência de RNA , Receptores de Fatores de Crescimento de Fibroblastos/genética , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Inhibitors of the protein methyltransferase Enhancer of Zeste Homolog 2 (EZH2) may have significant therapeutic potential for the treatment of B cell lymphomas and other cancer indications. The ability of the scientific community to explore fully the spectrum of EZH2-associated pathobiology has been hampered by the lack of in vivo-active tool compounds for this enzyme. Here we report the discovery and characterization of EPZ011989, a potent, selective, orally bioavailable inhibitor of EZH2 with useful pharmacokinetic properties. EPZ011989 demonstrates significant tumor growth inhibition in a mouse xenograft model of human B cell lymphoma. Hence, this compound represents a powerful tool for the expanded exploration of EZH2 activity in biology.
RESUMO
Inhibition of tumor angiogenesis by blockading the vascular endothelial growth factor (VEGF) signaling pathway is a promising therapeutic strategy for thyroid cancer. Lenvatinib mesilate (lenvatinib) is a potent inhibitor of VEGF receptors (VEGFR1-3) and other prooncogenic and prooncogenic receptor tyrosine kinases, including fibroblast growth factor receptors (FGFR1-4), platelet derived growth factor receptor α (PDGFRα), KIT, and RET. We examined the antitumor activity of lenvatinib against human thyroid cancer xenograft models in nude mice. Orally administered lenvatinib showed significant antitumor activity in 5 differentiated thyroid cancer (DTC), 5 anaplastic thyroid cancer (ATC), and 1 medullary thyroid cancer (MTC) xenograft models. Lenvatinib also showed antiangiogenesis activity against 5 DTC and 5 ATC xenografts, while lenvatinib showed in vitro antiproliferative activity against only 2 of 11 thyroid cancer cell lines: that is, RO82-W-1 and TT cells. Western blot analysis showed that cultured RO82-W-1 cells overexpressed FGFR1 and that lenvatinib inhibited the phosphorylation of FGFR1 and its downstream effector FRS2. Lenvatinib also inhibited the phosphorylation of RET with the activated mutation C634W in TT cells. These data demonstrate that lenvatinib provides antitumor activity mainly via angiogenesis inhibition but also inhibits FGFR and RET signaling pathway in preclinical human thyroid cancer models.
RESUMO
Many clinical cases of acquired resistance to the BRAF inhibitor vemurafenib have recently been reported. One of the causes of this acquired resistance is the BRAF downstream kinase point mutation MEK1-C121S. This mutation confers resistance to not only vemurafenib, but also to the allosteric MEK inhibitor selumetinib (AZD6244). Here, we investigated the pharmacologic activities and effectiveness of the novel MEK inhibitor E6201 against BRAF (v-raf murine sarcoma viral oncogene homolog B1)-V600E mutant melanoma harboring the MEK1-C121S mutation. A cell-free assay confirmed that E6201 is an ATP-competitive MEK inhibitor, meaning it has a different binding mode with MEK compared with allosteric MEK inhibitors. E6201 is more effective against BRAF-V600E mutant melanoma compared with BRAF wild-type melanoma based on MEK inhibition. We found that the acquired MEK1-C121S mutation in BRAF-V600E mutant melanoma conferred resistance to both vemurafenib and selumetinib but not E6201. The effectiveness of E6201 in this preclinical study is a result of its binding with MEK1 far from the C121S point mutation so the mutation is unable to influence the MAPK pathway inhibitory activity. These results support further clinical investigation of E6201.