Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Clin Cancer Res ; 30(10): 2181-2192, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38437671

RESUMEN

PURPOSE: FGFR2 and FGFR3 show oncogenic activation in many cancer types, often through chromosomal fusion or extracellular domain mutation. FGFR2 and FGFR3 alterations are most prevalent in intrahepatic cholangiocarcinoma (ICC) and bladder cancers, respectively, and multiple selective reversible and covalent pan-FGFR tyrosine kinase inhibitors (TKI) have been approved in these contexts. However, resistance, often due to acquired secondary mutations in the FGFR2/3 kinase domain, limits efficacy. Resistance is typically polyclonal, involving a spectrum of different mutations that most frequently affect the molecular brake and gatekeeper residues (N550 and V565 in FGFR2). EXPERIMENTAL DESIGN: Here, we characterize the activity of the next-generation covalent FGFR inhibitor, KIN-3248, in preclinical models of FGFR2 fusion+ ICC harboring a series of secondary kinase domain mutations, in vitro and in vivo. We also test select FGFR3 alleles in bladder cancer models. RESULTS: KIN-3248 exhibits potent selectivity for FGFR1-3 and retains activity against various FGFR2 kinase domain mutations, in addition to being effective against FGFR3 V555M and N540K mutations. Notably, KIN-3248 activity extends to the FGFR2 V565F gatekeeper mutation, which causes profound resistance to currently approved FGFR inhibitors. Combination treatment with EGFR or MEK inhibitors potentiates KIN-3248 efficacy in vivo, including in models harboring FGFR2 kinase domain mutations. CONCLUSIONS: Thus, KIN-3248 is a novel FGFR1-4 inhibitor whose distinct activity profile against FGFR kinase domain mutations highlights its potential for the treatment of ICC and other FGFR-driven cancers.


Asunto(s)
Mutación , Inhibidores de Proteínas Quinasas , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos , Neoplasias de la Vejiga Urinaria , Ensayos Antitumor por Modelo de Xenoinjerto , Humanos , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/antagonistas & inhibidores , Animales , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Ratones , Línea Celular Tumoral , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Resistencia a Antineoplásicos/genética , Receptor Tipo 3 de Factor de Crecimiento de Fibroblastos/genética , Receptor Tipo 3 de Factor de Crecimiento de Fibroblastos/antagonistas & inhibidores , Colangiocarcinoma/tratamiento farmacológico , Colangiocarcinoma/genética , Colangiocarcinoma/patología , Proliferación Celular/efectos de los fármacos
2.
J Med Chem ; 67(3): 1734-1746, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38267212

RESUMEN

Fibroblast growth factor receptor (FGFR) alterations are present as oncogenic drivers and bypass mechanisms in many forms of cancer. These alterations can include fusions, amplifications, rearrangements, and mutations. Acquired drug resistance to current FGFR inhibitors often results in disease progression and unfavorable outcomes for patients. Genomic profiling of tumors refractory to current FGFR inhibitors in the clinic has revealed several acquired driver alterations that could be the target of next generation therapeutics. Herein, we describe how structure-based drug design (SBDD) was used to enable the discovery of the potent and kinome selective pan-FGFR inhibitor KIN-3248, which is active against many acquired resistance mutations. KIN-3248 is currently in phase I clinical development for the treatment of advanced tumors harboring FGFR2 and/or FGFR3 gene alterations.


Asunto(s)
Neoplasias , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos , Humanos , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Mutación , Progresión de la Enfermedad , Inhibidores de Proteínas Quinasas/efectos adversos , Receptor Tipo 3 de Factor de Crecimiento de Fibroblastos
3.
Blood ; 137(13): 1792-1803, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33024987

RESUMEN

Ivosidenib (AG-120) and enasidenib (AG-221) are targeted oral inhibitors of the mutant isocitrate dehydrogenase (mIDH) 1 and 2 enzymes, respectively. Given their effectiveness as single agents in mIDH1/2 relapsed or refractory acute myeloid leukemia (AML), this phase 1 study evaluated the safety and efficacy of ivosidenib or enasidenib combined with intensive chemotherapy in patients with newly diagnosed mIDH1/2 AML. Ivosidenib 500 mg once daily and enasidenib 100 mg once daily were well tolerated in this setting, with safety profiles generally consistent with those of induction and consolidation chemotherapy alone. The frequency of IDH differentiation syndrome was low, as expected given the concurrent administration of cytotoxic chemotherapy. In patients receiving ivosidenib, the frequency and grades of QT interval prolongation were similar to those observed with ivosidenib monotherapy. Increases in total bilirubin were more frequently observed in patients treated with enasidenib, consistent with this inhibitor's known potential to inhibit UGT1A1, but did not appear to have significant clinical consequences. In patients receiving ivosidenib (n = 60) or enasidenib (n = 91), end-of-induction complete remission (CR) rates were 55% and 47%, respectively, and CR/CR with incomplete neutrophil or platelet recovery (CR/CRi/CRp) rates were 72% and 63%, respectively. In patients with a best overall response of CR/CRi/CRp, 16/41 (39%) receiving ivosidenib had IDH1 mutation clearance and 15/64 (23%) receiving enasidenib had IDH2 mutation clearance by digital polymerase chain reaction; furthermore, 16/20 (80%) and 10/16 (63%), respectively, became negative for measurable residual disease by multiparameter flow cytometry. This trial was registered at www.clinicaltrials.gov as #NCT02632708.


Asunto(s)
Aminopiridinas/uso terapéutico , Antineoplásicos/uso terapéutico , Glicina/análogos & derivados , Leucemia Mieloide Aguda/tratamiento farmacológico , Piridinas/uso terapéutico , Triazinas/uso terapéutico , Adulto , Anciano , Aminopiridinas/efectos adversos , Antineoplásicos/efectos adversos , Femenino , Glicina/efectos adversos , Glicina/uso terapéutico , Humanos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/genética , Masculino , Persona de Mediana Edad , Mutación/efectos de los fármacos , Piridinas/efectos adversos , Resultado del Tratamiento , Triazinas/efectos adversos , Adulto Joven
4.
J Clin Oncol ; 39(1): 57-65, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33119479

RESUMEN

PURPOSE: Ivosidenib is an oral inhibitor of the mutant isocitrate dehydrogenase 1 (IDH1) enzyme, approved for treatment of IDH1-mutant (mIDH1) acute myeloid leukemia (AML). Preclinical work suggested that addition of azacitidine to ivosidenib enhances mIDH1 inhibition-related differentiation and apoptosis. PATIENTS AND METHODS: This was an open-label, multicenter, phase Ib trial comprising dose-finding and expansion stages to evaluate safety and efficacy of combining oral ivosidenib 500 mg once daily continuously with subcutaneous azacitidine 75 mg/m2 on days 1-7 in 28-day cycles in patients with newly diagnosed mIDH1 AML ineligible for intensive induction chemotherapy (ClinicalTrials.gov identifier: NCT02677922). RESULTS: Twenty-three patients received ivosidenib plus azacitidine (median age, 76 years; range, 61-88 years). Treatment-related grade ≥ 3 adverse events occurring in > 10% of patients were neutropenia (22%), anemia (13%), thrombocytopenia (13%), and electrocardiogram QT prolongation (13%). Adverse events of special interest included all-grade IDH differentiation syndrome (17%), all-grade electrocardiogram QT prolongation (26%), and grade ≥ 3 leukocytosis (9%). Median treatment duration was 15.1 months (range, 0.3-32.2 months); 10 patients remained on treatment as of February 19, 2019. The overall response rate was 78.3% (18/23 patients; 95% CI, 56.3% to 92.5%), and the complete remission rate was 60.9% (14/23 patients; 95% CI, 38.5% to 80.3%). With median follow-up of 16 months, median duration of response in responders had not been reached. The 12-month survival estimate was 82.0% (95% CI, 58.8% to 92.8%). mIDH1 clearance in bone marrow mononuclear cells by BEAMing (beads, emulsion, amplification, magnetics) digital polymerase chain reaction was seen in 10/14 patients (71.4%) achieving complete remission. CONCLUSION: Ivosidenib plus azacitidine was well tolerated, with an expected safety profile consistent with monotherapy with each agent. Responses were deep and durable, with most complete responders achieving mIDH1 mutation clearance.


Asunto(s)
Azacitidina/administración & dosificación , Inhibidores Enzimáticos/administración & dosificación , Glicina/análogos & derivados , Leucemia Mieloide Aguda/tratamiento farmacológico , Piridinas/administración & dosificación , Anciano , Anciano de 80 o más Años , Apoptosis/efectos de los fármacos , Quimioterapia Combinada , Femenino , Glicina/administración & dosificación , Humanos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/genética , Masculino , Persona de Mediana Edad
5.
Lancet Oncol ; 21(8): 1066-1076, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32653053

RESUMEN

BACKGROUND: Margetuximab, a novel, investigational, Fc-engineered, anti-HER2 monoclonal antibody, is designed to more effectively potentiate innate immunity than trastuzumab. We aimed to evaluate the safety, tolerability, and antitumour activity of margetuximab plus pembrolizumab (an anti-PD-1 monoclonal antibody) in previously treated patients with HER2-positive gastro-oesophageal adenocarcinoma. METHODS: CP-MGAH22-05 was a single-arm, open-label, phase 1b-2 dose-escalation and cohort expansion study done at 11 academic centres in the USA and Canada and 15 centres in southeast Asia (Korea, Taiwan, and Singapore) that enrolled men and women aged 18 years or older with histologically proven, unresectable, locally advanced or metastatic, HER2-positive, PD-L1-unselected gastro-oesophageal adenocarcinoma, with an Eastern Cooperative Oncology Group performance status of 0 or 1, who had progressed after at least one previous line of therapy with trastuzumab plus chemotherapy in the locally advanced unresectable or metastatic setting. In the dose-escalation phase, nine patients were treated: three received margetuximab 10 mg/kg intravenously plus pembrolizumab 200 mg intravenously every 3 weeks and six received the recommended phase 2 dose of margetuximab 15 mg/kg plus pembrolizumab 200 mg intravenously every 3 weeks. An additional 86 patients were enrolled in the phase 2 cohort expansion and received the recommended phase 2 dose. The primary endpoints were safety and tolerability, assessed in the safety population (patients who received at least one dose of either margetuximab or pembrolizumab) and the objective response rate as assessed by the investigator according to both Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, in the response-evaluable population (patients with measurable disease at baseline and who received the recommended phase 2 dose of margetuximab and pembrolizumab). This trial is registered with ClinicalTrials.gov, NCT02689284. Recruitment for the trial has completed and follow-up is ongoing. FINDINGS: Between Feb 11, 2016, and Oct 2, 2018, 95 patients were enrolled. Median follow-up was 19·9 months (IQR 10·7-23·1). The combination therapy showed acceptable safety and tolerability; there were no dose-limiting toxicities in the dose-escalation phase. The most common grade 3-4 treatment-related adverse events were anaemia (four [4%]) and infusion-related reactions (three [3%]). Serious treatment-related adverse events were reported in nine (9%) patients. No treatment-related deaths were reported. Objective responses were observed in 17 (18·48%; 95% CI 11·15-27·93) of 92 evaluable patients. INTERPRETATION: These findings serve as proof of concept of synergistic antitumour activity with the combination of an Fc-optimised anti-HER2 agent (margetuximab) along with anti-PD-1 checkpoint blockade (pembrolizumab). FUNDING: MacroGenics.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Esofágicas/tratamiento farmacológico , Receptor ErbB-2/antagonistas & inhibidores , Neoplasias Gástricas/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Antineoplásicos Inmunológicos/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad
6.
Front Oncol ; 9: 212, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31019892

RESUMEN

Background: HER2 antagonists have marked activity and are approved for the treatment of HER2 overexpressing breast and gastric cancers. Recent studies have shown that ERBB2 (HER2) gene amplification and overexpression may also be actionable in other tumor types. Inter- and intratumoral heterogeneity in HER2 status, however, poses a significant challenge in identifying patients that may benefit from HER2-targeted therapies. ERBB2 amplification as identified by circulating cell-free DNA (cfDNA), which circumvents tissue heterogeneity issues, is emerging as a robust biomarker predictive of response to anti-HER2 agents. Here, the prevalence and genomic landscape of ERBB2 alterations detectable by next-generation sequencing (NGS) of cfDNA was evaluated in a large cohort of Asian patients with advanced solid tumors. Methods: Results were queried for consecutive patients (n = 469) tested by a comprehensive 70/73-gene cfDNA NGS assay (Guardant360®) between November 2015 and June 2018. Patients with ERBB2 gene alterations including copy number amplifications (CNAs), single nucleotide variants (SNVs), and insertion-deletions (indels) were identified. Results: ERBB2 alterations were detected in 52 patients (11.1%); ERBB2 SNVs, CNAs, and indels were found in 27 (5.8%), 27 (5.8%), and 10 (2.1%) patients, respectively. ERBB2 amplification was most frequently identified in gastric (21.4%; 6/28), colorectal (11.1%; 5/45), lung (3.9%; 9/231), and breast (3.2%; 1/31) cancer patients. ERBB2 amplification was often mutually exclusive with other oncogenic alterations in gastric (83.3%; 5/6) and colorectal (60%; 3/5) cancer patients. ERBB2 copy number gains were also highest in gastric and colorectal cancers (median 4.8 and 6.6, respectively). We further report two cases of advanced gastric cancer patients, one treatment naïve, and the other having failed four lines of therapy, whose ERBB2 CNAs were identified by cfDNA and derived clinical benefit from HER2-based therapies. Conclusion: Our data indicate that ERBB2 amplification is a common event in solid tumors among Asian cancer patients. High ERBB2 incidence and copy number gains were observed in gastric and colorectal cancer patients, often in the absence of other oncogenic mutations, underscoring its likely role as the driver alteration in those settings. Finally, we show the potential of comprehensive cfDNA testing in identifying patients who are most likely to benefit from HER2-targeted therapies.

7.
JCO Precis Oncol ; 2: 1-13, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35135111

RESUMEN

PURPOSE: Liquid biopsies represent an attractive alternative to tissue biopsies, particularly rebiopsies, in determining patient eligibility for targeted therapies. Clinical utility of urine genotyping, however, has not been explored extensively. We evaluated epidermal growth factor receptor (EGFR) T790M detection in matched urine, plasma, and tissue and the clinical outcomes of patients with advanced non-small-cell lung cancer treated with rociletinib. METHODS: Tissue (n = 540), plasma (n = 482), and urine (n = 213) were collected from evaluable patients enrolled in TIGER-X, a phase I/II study. Genotyping was performed by therascreen EGFR testing in tissue, BEAMing in plasma, and a quantitative short footprint assay (Trovera) in urine, which was used to further examine discordant samples. RESULTS: Positive percent agreement with tissue T790M results was similar for urine (82%; 142 of 173) and plasma (81%; 313 of 387) genotyping. Urine and plasma together identified more patients who were T790M positive (92%) than tissue alone (83%) among matched samples (n = 177). The ability to identify mutations in plasma was strongly associated with M stage (P < .001); rate of T790M detection for patients with M1a/M0 disease increased from 54% for plasma alone to 85% when urine and plasma were both examined. Objective response rates of patients who were T790M positive were comparable between tumor (34%), plasma (32%), and urine (37%). CONCLUSION: Clinical response to rociletinib was comparable irrespective of whether T790M status was identified by liquid or tissue biopsy. Combined, urine and plasma identified a higher percentage of patients who were T790M positive than tumor genotyping alone and improved detection of T790M, particularly in the absence of distant metastases. These findings support the noninvasive analysis of urine and plasma before tumor rebiopsy when assessing T790M status.

8.
J Thorac Dis ; 9(Suppl 13): S1323-S1331, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29184671

RESUMEN

Precision medicine approaches in oncology are reliant on the accurate genomic characterization of tumors. While tissue remains the mainstay specimen for molecular testing, tumor biopsies are riddled with challenges and limitations due to their invasive and site-specific nature. Tumor inaccessibility and intratumoral heterogeneity, in particular, represent significant obstacles to the identification of actionable genetic alterations and hence effective mono- and combination therapy strategies. Proof-of-concept studies indicate that circulating tumor DNA (ctDNA) released from multiple tumor regions and anatomical locations is more reflective of intra- and intertumoral heterogeneity. Non-invasive liquid biopsy approaches that allow for the analysis of ctDNA are thus being increasingly implemented in routine patient care for the detection and monitoring of cancer-associated mutations. Indeed, the use of plasma testing to screen for epidermal growth factor receptor (EGFR) T790M mutant positive non-small cell lung cancer (NSCLC) patients eligible for treatment with third-generation EGFR inhibitors was recently approved by the U.S. Food and Drug Administration and is incorporated into the most recent version of the National Comprehensive Cancer Center guidelines as an alternative to tissue biopsy. Urine represents another liquid biopsy specimen that is distinguished by its ease of collection, option for home collection, and lack of temporal and volumetric collection restrictions. Importantly, there is an accumulating body of evidence supporting the clinical validity of urinary EGFR mutant testing for the identification and stratification of patients likely to benefit from EGFR-directed therapies and as a means to assess patient response, the presence of residual disease, and emergence of resistant tumor cell populations.

9.
Clin Cancer Res ; 23(12): 2981-2990, 2017 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-28011461

RESUMEN

Purpose: While multikinase inhibitors with RET activity are active in RET-rearranged thyroid and lung cancers, objective response rates are relatively low and toxicity can be substantial. The development of novel RET inhibitors with improved potency and/or reduced toxicity is thus an unmet need. RXDX-105 is a small molecule kinase inhibitor that potently inhibits RET. The purpose of the preclinical and clinical studies was to evaluate the potential of RXDX-105 as an effective therapy for cancers driven by RET alterations.Experimental design: The RET-inhibitory activity of RXDX-105 was assessed by biochemical and cellular assays, followed by in vivo tumor growth inhibition studies in cell line- and patient-derived xenograft models. Antitumor activity in patients was assessed by imaging and Response Evaluation Criteria in Solid Tumors (RECIST).Results: Biochemically, RXDX-105 inhibited wild-type RET, CCDC6-RET, NCOA4-RET, PRKAR1A-RET, and RET M918T with low to subnanomolar activity while sparing VEGFR2/KDR and VEGFR1/FLT. RXDX-105 treatment resulted in dose-dependent inhibition of proliferation of CCDC6-RET-rearranged and RET C634W-mutant cell lines and inhibition of downstream signaling pathways. Significant tumor growth inhibition in CCDC6-RET, NCOA4-RET, and KIF5B-RET-containing xenografts was observed, with the concomitant inhibition of p-ERK, p-AKT, and p-PLCγ. Additionally, a patient with advanced RET-rearranged lung cancer had a rapid and sustained response to RXDX-105 in both intracranial and extracranial disease.Conclusions: These data support the inclusion of patients bearing RET alterations in ongoing and future molecularly enriched clinical trials to explore RXDX-105 efficacy across a variety of tumor types. Clin Cancer Res; 23(12); 2981-90. ©2016 AACR.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Proteínas Proto-Oncogénicas c-ret/antagonistas & inhibidores , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Reordenamiento Génico/efectos de los fármacos , Humanos , Ratones , Mutación , Proteínas de Neoplasias/antagonistas & inhibidores , Neoplasias/genética , Neoplasias/patología , Inhibidores de Proteínas Quinasas/efectos adversos , Proteínas Proto-Oncogénicas c-ret/genética , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
10.
Nat Commun ; 7: 13597, 2016 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-27886180

RESUMEN

Rather than targeting tumour cells directly, elements of the tumour microenvironment can be modulated to sensitize tumours to the effects of therapy. Here we report a unique mechanism by which ectopic microRNA-103 can manipulate tumour-associated endothelial cells to enhance tumour cell death. Using gain-and-loss of function approaches, we show that miR-103 exacerbates DNA damage and inhibits angiogenesis in vitro and in vivo. Local, systemic or vascular-targeted delivery of miR-103 in tumour-bearing mice decreased angiogenesis and tumour growth. Mechanistically, miR-103 regulation of its target gene TREX1 in endothelial cells governs the secretion of pro-inflammatory cytokines into the tumour microenvironment. Our data suggest that this inflammatory milieu may potentiate tumour cell death by supporting immune activation and inducing tumour expression of Fas and TRAIL receptors. Our findings reveal miR-mediated crosstalk between vasculature and tumour cells that can be exploited to improve the efficacy of chemotherapy and radiation.


Asunto(s)
Exodesoxirribonucleasas/genética , MicroARNs/metabolismo , Neoplasias/genética , Neovascularización Patológica/genética , Fosfoproteínas/genética , Microambiente Tumoral/genética , Animales , Línea Celular Tumoral , Regulación hacia Abajo , Exodesoxirribonucleasas/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/administración & dosificación , MicroARNs/genética , Neoplasias/inmunología , Neoplasias/patología , Neoplasias/terapia , Neovascularización Patológica/patología , Neovascularización Patológica/radioterapia , Fosfoproteínas/metabolismo , ARN Interferente Pequeño/metabolismo , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Microambiente Tumoral/efectos de la radiación , Ensayos Antitumor por Modelo de Xenoinjerto , Receptor fas/metabolismo
11.
Nat Commun ; 6: 8154, 2015 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-26333361

RESUMEN

Although oncology therapy regimens commonly include radiation and genotoxic drugs, tumour cells typically develop resistance to these interventions. Here we report that treatment of tumours with ionizing radiation or genotoxic drugs drives p21-activated kinase 1 (PAK1)-mediated phosphorylation of CRAF on Serine 338 (pS338) triggering a kinase-independent mechanism of DNA repair and therapeutic resistance. CRAF pS338 recruits CHK2, a cell cycle checkpoint kinase involved in DNA repair, and promotes CHK2 phosphorylation/activation to enhance the tumour cell DNA damage response. Accordingly, a phospho-mimetic mutant of CRAF (S338D) is sufficient to induce the CRAF/CHK2 association enhancing tumour radioresistance, while an allosteric CRAF inhibitor sensitizes tumour cells to ionizing radiation or genotoxic drugs. Our findings establish a role for CRAF in the DNA damage response that is independent from its canonical function as a kinase.


Asunto(s)
Quinasa de Punto de Control 2/efectos de la radiación , Daño del ADN/efectos de la radiación , Proteínas Proto-Oncogénicas c-raf/efectos de la radiación , Tolerancia a Radiación/genética , Radiación Ionizante , Quinasas p21 Activadas/efectos de la radiación , Animales , Línea Celular Tumoral , Quinasa de Punto de Control 2/metabolismo , Daño del ADN/genética , Técnica del Anticuerpo Fluorescente , Células HCT116 , Humanos , Immunoblotting , Inmunoprecipitación , Ratones , Mutación , Trasplante de Neoplasias , Fosforilación/efectos de la radiación , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-raf/genética , Serina/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasas p21 Activadas/genética
12.
Cancer Res ; 75(21): 4466-73, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26297735

RESUMEN

Integrin αvß3 has been implicated as a driver of aggressive and metastatic disease, and is upregulated during glioblastoma progression. Here, we demonstrate that integrin αvß3 allows glioblastoma cells to counteract senescence through a novel tissue-specific effector mechanism involving recruitment and activation of the cytoskeletal regulatory kinase PAK4. Mechanistically, targeting either αvß3 or PAK4 led to emergence of a p21-dependent, p53-independent cell senescence phenotype. Notably, glioblastoma cells did not exhibit a similar requirement for either other integrins or additional PAK family members. Moreover, αvß3/PAK4 dependence was not found to be critical in epithelial cancers. Taken together, our findings established that glioblastomas are selectively addicted to this pathway as a strategy to evade oncogene-induced senescence, with implications that inhibiting the αvß3-PAK4 signaling axis may offer novel therapeutic opportunities to target this aggressive cancer.


Asunto(s)
Neoplasias Encefálicas/genética , Senescencia Celular/genética , Glioblastoma/genética , Integrina alfaVbeta3/genética , Quinasas p21 Activadas/genética , Animales , Neoplasias Encefálicas/patología , Proliferación Celular/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Femenino , Glioblastoma/patología , Humanos , Integrina alfaVbeta3/metabolismo , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Interferencia de ARN , ARN Interferente Pequeño , Transducción de Señal/genética , Esferoides Celulares , Trasplante Heterólogo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Vitronectina/metabolismo , Quinasas p21 Activadas/metabolismo
13.
Dev Cell ; 30(3): 295-308, 2014 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-25117682

RESUMEN

Although integrin αvß3 is linked to cancer progression, its role in epithelial development is unclear. Here, we show that αvß3 plays a critical role in adult mammary stem cells (MaSCs) during pregnancy. Whereas αvß3 is a luminal progenitor marker in the virgin gland, we noted increased αvß3 expression in MaSCs at midpregnancy. Accordingly, mice lacking αvß3 or expressing a signaling-deficient receptor showed defective mammary gland morphogenesis during pregnancy. This was associated with decreased MaSC expansion, clonogenicity, and expression of Slug, a master regulator of MaSCs. Surprisingly, αvß3-deficient mice displayed normal development of the virgin gland with no effect on luminal progenitors. Transforming growth factor ß2 (TGF-ß2) induced αvß3 expression, enhancing Slug nuclear accumulation and MaSC clonogenicity. In human breast cancer cells, αvß3 was necessary and sufficient for Slug activation, tumorsphere formation, and tumor initiation. Thus, pregnancy-associated MaSCs require a TGF-ß2/αvß3/Slug pathway, which may contribute to breast cancer progression and stemness.


Asunto(s)
Transformación Celular Neoplásica/metabolismo , Integrina alfaVbeta3/metabolismo , Glándulas Mamarias Animales/citología , Células Madre/citología , Factores de Transcripción/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Diferenciación Celular , Células Epiteliales/citología , Femenino , Humanos , Integrina alfaVbeta3/deficiencia , Ratones , Embarazo , Factores de Transcripción de la Familia Snail , Factor de Crecimiento Transformador beta2/metabolismo
14.
Proc Natl Acad Sci U S A ; 111(21): 7783-8, 2014 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-24817692

RESUMEN

Epigenetic regulation of gene expression by DNA methylation plays a central role in the maintenance of cellular homeostasis. Here we present evidence implicating the DNA methylation program in the regulation of hypoxia-inducible factor (HIF) oxygen-sensing machinery and hypoxic cell metabolism. We show that DNA methyltransferase 3a (DNMT3a) methylates and silences the HIF-2α gene (EPAS1) in differentiated cells. Epigenetic silencing of EPAS1 prevents activation of the HIF-2α gene program associated with hypoxic cell growth, thereby limiting the proliferative capacity of adult cells under low oxygen tension. Naturally occurring defects in DNMT3a, observed in primary tumors and malignant cells, cause the unscheduled activation of EPAS1 in early dysplastic foci. This enables incipient cancer cells to exploit the HIF-2α pathway in the hypoxic tumor microenvironment necessary for the formation of cellular masses larger than the oxygen diffusion limit. Reintroduction of DNMT3a in DNMT3a-defective cells restores EPAS1 epigenetic silencing, prevents hypoxic cell growth, and suppresses tumorigenesis. These data support a tumor-suppressive role for DNMT3a as an epigenetic regulator of the HIF-2α oxygen-sensing pathway and the cellular response to hypoxia.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Carcinogénesis/genética , Hipoxia de la Célula/fisiología , ADN (Citosina-5-)-Metiltransferasas/fisiología , Metilación de ADN/fisiología , Epigénesis Genética/fisiología , Animales , Carcinogénesis/metabolismo , Línea Celular Tumoral , ADN (Citosina-5-)-Metiltransferasas/genética , Metilación de ADN/genética , ADN Metiltransferasa 3A , Epigénesis Genética/genética , Femenino , Humanos , Ratones , Ratones Desnudos
15.
Nat Cell Biol ; 16(5): 457-68, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24747441

RESUMEN

Tumour cells, with stem-like properties, are highly aggressive and often show drug resistance. Here, we reveal that integrin α(v)ß3 serves as a marker of breast, lung and pancreatic carcinomas with stem-like properties that are highly resistant to receptor tyrosine kinase inhibitors such as erlotinib. This was observed in vitro and in mice bearing patient-derived tumour xenografts or in clinical specimens from lung cancer patients who had progressed on erlotinib. Mechanistically, α(v)ß3, in the unliganded state, recruits KRAS and RalB to the tumour cell plasma membrane, leading to the activation of TBK1 and NF-κB. In fact, α(v)ß3 expression and the resulting KRAS-RalB-NF-κB pathway were both necessary and sufficient for tumour initiation, anchorage independence, self-renewal and erlotinib resistance. Pharmacological targeting of this pathway with bortezomib reversed both tumour stemness and erlotinib resistance. These findings not only identify α(v)ß3 as a marker/driver of carcinoma stemness but also reveal a therapeutic strategy to sensitize such tumours to RTK inhibition.


Asunto(s)
Resistencia a Antineoplásicos , Receptores ErbB/antagonistas & inhibidores , Integrina beta3/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Células Madre Neoplásicas/efectos de los fármacos , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas/metabolismo , Proteínas de Unión al GTP ral/metabolismo , Proteínas ras/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos Clínicos Fase II como Asunto , Resistencia a Antineoplásicos/genética , Receptores ErbB/genética , Receptores ErbB/metabolismo , Clorhidrato de Erlotinib , Femenino , Humanos , Integrina alfaVbeta3/metabolismo , Integrina beta3/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos NOD , Ratones Desnudos , Ratones SCID , Terapia Molecular Dirigida , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Fenotipo , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-rel/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-rel/metabolismo , Proteínas Proto-Oncogénicas p21(ras) , Quinazolinas/uso terapéutico , Interferencia de ARN , Ensayos Clínicos Controlados Aleatorios como Asunto , Transducción de Señal/efectos de los fármacos , Esferoides Celulares , Factores de Tiempo , Transfección , Carga Tumoral/efectos de los fármacos , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto , Proteínas de Unión al GTP ral/genética , Proteínas ras/genética
16.
Nature ; 486(7401): 126-9, 2012 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-22678294

RESUMEN

Protein synthesis involves the translation of ribonucleic acid information into proteins, the building blocks of life. The initial step of protein synthesis is the binding of the eukaryotic translation initiation factor 4E (eIF4E) to the 7-methylguanosine (m(7)-GpppG) 5' cap of messenger RNAs. Low oxygen tension (hypoxia) represses cap-mediated translation by sequestering eIF4E through mammalian target of rapamycin (mTOR)-dependent mechanisms. Although the internal ribosome entry site is an alternative translation initiation mechanism, this pathway alone cannot account for the translational capacity of hypoxic cells. This raises a fundamental question in biology as to how proteins are synthesized in periods of oxygen scarcity and eIF4E inhibition. Here we describe an oxygen-regulated translation initiation complex that mediates selective cap-dependent protein synthesis. We show that hypoxia stimulates the formation of a complex that includes the oxygen-regulated hypoxia-inducible factor 2α (HIF-2α), the RNA-binding protein RBM4 and the cap-binding eIF4E2, an eIF4E homologue. Photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) analysis identified an RNA hypoxia response element (rHRE) that recruits this complex to a wide array of mRNAs, including that encoding the epidermal growth factor receptor. Once assembled at the rHRE, the HIF-2α-RBM4-eIF4E2 complex captures the 5' cap and targets mRNAs to polysomes for active translation, thereby evading hypoxia-induced repression of protein synthesis. These findings demonstrate that cells have evolved a program by which oxygen tension switches the basic translation initiation machinery.


Asunto(s)
Oxígeno/metabolismo , Iniciación de la Cadena Peptídica Traduccional , Regiones no Traducidas 3'/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Hipoxia de la Célula/fisiología , Línea Celular , Línea Celular Tumoral , Receptores ErbB/biosíntesis , Receptores ErbB/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Humanos , Factor 1 Inducible por Hipoxia/metabolismo , Oxígeno/farmacología , Iniciación de la Cadena Peptídica Traduccional/efectos de los fármacos , Polirribosomas/genética , Polirribosomas/metabolismo , Proteínas de Unión a Caperuzas de ARN/metabolismo , Caperuzas de ARN/genética , Caperuzas de ARN/metabolismo , Proteínas de Unión al ARN/metabolismo
17.
Nat Med ; 17(12): 1641-5, 2011 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-22081024

RESUMEN

RAF kinases regulate cell proliferation and survival and can be dysregulated in tumors. The role of RAF in cell proliferation has been linked to its ability to activate mitogen-activated protein kinase kinase 1 (MEK) and mitogen-activated protein kinase 1 (ERK). Here we identify a MEK-independent role for RAF in tumor growth. Specifically, in mitotic cells, CRAF becomes phosphorylated on Ser338 and localizes to the mitotic spindle of proliferating tumor cells in vitro as well as in murine tumor models and in biopsies from individuals with cancer. Treatment of tumors with allosteric inhibitors, but not ATP-competitive RAF inhibitors, prevents CRAF phosphorylation on Ser338 and localization to the mitotic spindle and causes cell-cycle arrest at prometaphase. Furthermore, we identify phospho-Ser338 CRAF as a potential biomarker for tumor progression and a surrogate marker for allosteric RAF blockade. Mechanistically, CRAF, but not BRAF, associates with Aurora kinase A (Aurora-A) and Polo-like kinase 1 (Plk1) at the centrosomes and spindle poles during G2/M. Indeed, allosteric or genetic inhibition of phospho-Ser338 CRAF impairs Plk1 activation and accumulation at the kinetochores, causing prometaphase arrest, whereas a phospho-mimetic Ser338D CRAF mutant potentiates Plk1 activation, mitosis and tumor progression in mice. These findings show a previously undefined role for RAF in tumor progression beyond the RAF-MEK-ERK paradigm, opening new avenues for targeting RAF in cancer.


Asunto(s)
MAP Quinasa Quinasa 1/metabolismo , Mitosis , Neoplasias/patología , Proteínas Proto-Oncogénicas c-raf/metabolismo , Animales , Aurora Quinasa A , Aurora Quinasas , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Proliferación Celular , Centrosoma/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Cinetocoros/metabolismo , MAP Quinasa Quinasa 1/genética , Ratones , Ratones Desnudos , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-raf/genética , Transducción de Señal , Huso Acromático/metabolismo , Quinasa Tipo Polo 1
19.
Cancer Res ; 70(2): 730-40, 2010 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-20068146

RESUMEN

Inappropriate expression of Ets-1 is observed in a variety of human cancers, and its forced expression in cultured cells results in transformation, autonomous proliferation, and tumor formation. The basis by which Ets-1 confers autonomous growth, one of the primary hallmarks of cancer cells and a critical component of persistent proliferation, has yet to be fully explained. Using a variety of cancer cell lines, we show that inhibition of Ets-1 blocks tumor formation and cell proliferation in vivo and autonomous growth in culture. A screen of multiple diffusible growth factors revealed that inhibition of Ets-1 results in the specific downregulation of transforming growth factor alpha (TGFalpha), the proximal promoter region of which contains multiple ETS family DNA binding sites that can be directly bound and regulated by Ets-1. Notably, rescuing TGFalpha expression in Ets-1-silenced cells was sufficient to restore tumor cell proliferation in vivo and autonomous growth in culture. These results reveal a previously unrecognized mechanism by which Ets-1 oncogenic activity can be explained in human cancer through its ability to regulate the important cellular mitogen TGFalpha.


Asunto(s)
Neoplasias/metabolismo , Neoplasias/patología , Proteína Proto-Oncogénica c-ets-1/antagonistas & inhibidores , Factor de Crecimiento Transformador alfa/metabolismo , Procesos de Crecimiento Celular/fisiología , Línea Celular Tumoral , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Glioma/genética , Glioma/metabolismo , Glioma/patología , Humanos , Neoplasias Renales/genética , Neoplasias Renales/metabolismo , Neoplasias Renales/patología , Masculino , Neoplasias/genética , Regiones Promotoras Genéticas , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Unión Proteica , Proteína Proto-Oncogénica c-ets-1/genética , Proteína Proto-Oncogénica c-ets-1/metabolismo , Transfección , Factor de Crecimiento Transformador alfa/biosíntesis
20.
Proc Natl Acad Sci U S A ; 106(50): 21306-11, 2009 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19955413

RESUMEN

Cancer development is a multistep process, driven by a series of genetic and environmental alterations, that endows cells with a set of hallmark traits required for tumorigenesis. It is broadly accepted that growth signal autonomy, the first hallmark of malignancies, can be acquired through multiple genetic mutations that activate an array of complex, cancer-specific growth circuits [Hanahan D, Weinberg RA (2000) The hallmarks of cancer. Cell 100:57-70; Vogelstein B, Kinzler KW (2004) Cancer genes and the pathways they control. Nat Med 10:789-799]. The superfluous nature of these pathways is thought to severely limit therapeutic approaches targeting tumor proliferation, and it has been suggested that this strategy be abandoned in favor of inhibiting more systemic hallmarks, including angiogenesis (Ellis LM, Hicklin DJ (2008) VEGF-targeted therapy: Mechanisms of anti-tumor activity. Nat Rev Cancer 8:579-591; Stommel JM, et al. (2007) Coactivation of receptor tyrosine kinases affects the response of tumor cells to targeted therapies. Science 318:287-290; Kerbel R, Folkman J (2002) Clinical translation of angiogenesis inhibitors. Nat Rev Cancer 2:727-739; Kaiser J (2008) Cancer genetics: A detailed genetic portrait of the deadliest human cancers. Science 321:1280-1281]. Here, we report the unexpected observation that genetically diverse cancers converge at a common and obligatory growth axis instigated by HIF-2alpha, an element of the oxygen-sensing machinery. Inhibition of HIF-2alpha prevents the in vivo growth and tumorigenesis of highly aggressive glioblastoma, colorectal, and non-small-cell lung carcinomas and the in vitro autonomous proliferation of several others, regardless of their mutational status and tissue of origin. The concomitant deactivation of select receptor tyrosine kinases, including the EGFR and IGF1R, as well as downstream ERK/Akt signaling, suggests that HIF-2alpha exerts its proliferative effects by endorsing these major pathways. Consistently, silencing these receptors phenocopies the loss of HIF-2alpha oncogenic activity, abrogating the serum-independent growth of human cancer cells in culture. Based on these data, we propose an alternative to the predominant view that cancers exploit independent autonomous growth pathways and reveal HIF-2alpha as a potentially universal culprit in promoting the persistent proliferation of neoplastic cells.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Carcinoma de Pulmón de Células no Pequeñas/etiología , Glioma/etiología , Neoplasias/etiología , Oncogenes , Transducción de Señal , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/antagonistas & inhibidores , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral , Receptores ErbB/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Glioma/metabolismo , Humanos , Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Interferente Pequeño/farmacología , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptor IGF Tipo 1/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...