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To detect the epigenetic drift of time passing, we determined the genome-wide distributions of mono- and tri-methylated lysine 4 and acetylated and tri-methylated lysine 27 of histone H3 in the livers of healthy 3, 6 and 12 months old C57BL/6 mice. The comparison of different age profiles of histone H3 marks revealed global redistribution of histone H3 modifications with time, in particular in intergenic regions and near transcription start sites, as well as altered correlation between the profiles of different histone modifications. Moreover, feeding mice with caloric restriction diet, a treatment known to retard aging, reduced the extent of changes occurring during the first year of life in these genomic regions.
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Código de Histonas , Histonas , Acetilación , Animales , Histonas/metabolismo , Hígado/metabolismo , Lisina/metabolismo , Ratones , Ratones Endogámicos C57BLRESUMEN
Checkpoint inhibitors (CI) instigate anticancer immunity in many neoplastic diseases, albeit only in a fraction of patients. The clinical success of cyclophosphamide (C)-based haploidentical stem-cell transplants indicates that this drug may re-orchestrate the immune system. Using models of triple-negative breast cancer (TNBC) with different intratumoral immune contexture, we demonstrate that a combinatorial therapy of intermittent C, CI, and vinorelbine activates antigen-presenting cells (APC), and abrogates local and metastatic tumor growth by a T-cell-related effect. Single-cell transcriptome analysis of >50,000 intratumoral immune cells after therapy treatment showed a gene signature suggestive of a change resulting from exposure to a mitogen, ligand, or antigen for which it is specific, as well as APC-to-T-cell adhesion. This transcriptional program also increased intratumoral Tcf1+ stem-like CD8+ T cells and altered the balance between terminally and progenitor-exhausted T cells favoring the latter. Overall, our data support the clinical investigation of this therapy in TNBC. SIGNIFICANCE: A combinatorial therapy in mouse models of breast cancer increases checkpoint inhibition by activating antigen-presenting cells, enhancing intratumoral Tcf1+ stem-like CD8+ T cells, and increasing progenitor exhausted CD8+ T cells.
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Antineoplásicos/farmacología , Linfocitos T CD8-positivos/efectos de los fármacos , Ciclofosfamida/farmacología , Inhibidores de Puntos de Control Inmunológico/farmacología , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Vinorelbina/farmacología , Animales , Células Presentadoras de Antígenos/efectos de los fármacos , Células Presentadoras de Antígenos/inmunología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Linfocitos T CD8-positivos/inmunología , Adhesión Celular , Femenino , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Inmunidad Celular , Ratones , Ratones Endogámicos BALB C , Transcriptoma , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/inmunologíaRESUMEN
The rapid rise to fame of immuno-oncology (IO) drugs has generated unprecedented interest in the industry, patients and doctors, and has had a major impact in the treatment of most cancers. An interesting aspect in the clinical development of many IO agents is the increasing reliance on nonconventional trial design, including the so-called 'master protocols' that incorporate various adaptive features and often heavily rely on biomarkers to select patient populations most likely to benefit. These novel designs promise to maximize the clinical benefit that can be reaped from clinical research, but are not without costs. Their acceptance as solid evidence basis for use outside of the research context requires profound cultural changes by multiple stakeholders, including regulatory bodies, decision-makers, statisticians, researchers, doctors and, most importantly, patients. Here we review characteristics of recent and ongoing trials testing IO drugs with unconventional design, and we highlight trends and critical aspects.
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Inmunoterapia/métodos , Oncología Médica/métodos , Neoplasias/terapia , HumanosRESUMEN
PURPOSE: Trials that accrue participants on the basis of genetic biomarkers are a powerful means of testing targeted drugs, but they are often complicated by the rarity of the biomarker-positive population. Umbrella trials circumvent this by testing multiple hypotheses to maximize accrual. However, bigger trials have higher chances of conflicting treatment allocations because of the coexistence of multiple actionable alterations; allocation strategies greatly affect the efficiency of enrollment and should be carefully planned on the basis of relative mutation frequencies, leveraging information from large sequencing projects. METHODS: We developed software named Precision Trial Drawer (PTD) to estimate parameters that are useful for designing precision trials, most importantly, the number of patients needed to molecularly screen (NNMS) and the allocation rule that maximizes patient accrual on the basis of mutation frequency, systematically assigning patients with conflicting allocations to the drug associated with the rarer mutation. We used data from The Cancer Genome Atlas to show their potential in a 10-arm imaginary trial of multiple cancers on the basis of genetic alterations suggested by the past Molecular Analysis for Personalised Therapy (MAP) conference. We validated PTD predictions versus real data from the SHIVA (A Randomized Phase II Trial Comparing Therapy Based on Tumor Molecular Profiling Versus Conventional Therapy in Patients With Refractory Cancer) trial. RESULTS: In the MAP imaginary trial, PTD-optimized allocation reduces number of patients needed to molecularly screen by up to 71.8% (3.5 times) compared with nonoptimal trial designs. In the SHIVA trial, PTD correctly predicted the fraction of patients with actionable alterations (33.51% [95% CI, 29.4% to 37.6%] in imaginary v 32.92% [95% CI, 28.2% to 37.6%] expected) and allocation to specific treatment groups (RAS/MEK, PI3K/mTOR, or both). CONCLUSION: PTD correctly predicts crucial parameters for the design of multiarm genetic biomarker-driven trials. PTD is available as a package in the R programming language and as an open-access Web-based app. It represents a useful resource for the community of precision oncology trialists. The Web-based app is available at https://gmelloni.github.io/ptd/shinyapp.html.
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UNLABELLED: The identification of genes maintaining cancer growth is critical to our understanding of tumorigenesis. We report the first in vivo genetic screen of patient-derived tumors, using metastatic melanomas and targeting 236 chromatin genes by expression of specific shRNA libraries. Our screens revealed unprecedented numerosity of genes indispensable for tumor growth (â¼50% of tested genes) and unexpected functional heterogeneity among patients (<15% in common). Notably, these genes were not activated by somatic mutations in the same patients and are therefore distinguished from mutated cancer driver genes. We analyzed underlying molecular mechanisms of one of the identified genes, the Histone-lysine N-methyltransferase KMT2D, and showed that it promotes tumorigenesis by dysregulating a subset of transcriptional enhancers and target genes involved in cell migration. The assembly of enhancer genomic patterns by activated KMT2D was highly patient-specific, regardless of the identity of transcriptional targets, suggesting that KMT2D might be activated by distinct upstream signaling pathways. SIGNIFICANCE: Drug targeting of biologically relevant cancer-associated mutations is considered a critical strategy to control cancer growth. Our functional in vivo genetic screens of patient-derived tumors showed unprecedented numerosity and interpatient heterogeneity of genes that are essential for tumor growth, but not mutated, suggesting that multiple, patient-specific signaling pathways are activated in tumors. Cancer Discov; 6(6); 650-63. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 561.
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Transformación Celular Neoplásica/genética , Estudios de Asociación Genética , Pruebas Genéticas , Neoplasias/diagnóstico , Neoplasias/genética , Fenotipo , Animales , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Biología Computacional/métodos , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Elementos de Facilitación Genéticos , Epigénesis Genética , Epigenómica/métodos , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Predisposición Genética a la Enfermedad , Xenoinjertos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Metástasis de la Neoplasia , Proteínas de Neoplasias/metabolismo , Unión Proteica , ARN Interferente Pequeño/genética , Reproducibilidad de los ResultadosRESUMEN
NGF has been implicated in forebrain neuroprotection from amyloidogenesis and Alzheimer's disease (AD). However, the underlying molecular mechanisms are still poorly understood. Here, we investigated the role of NGF signalling in the metabolism of amyloid precursor protein (APP) in forebrain neurons using primary cultures of septal neurons and acute septo-hippocampal brain slices. In this study, we show that NGF controls the basal level of APP phosphorylation at Thr668 (T668) by downregulating the activity of the Ser/Thr kinase JNK(p54) through the Tyr kinase signalling adaptor SH2-containing sequence C (ShcC). We also found that the specific NGF receptor, Tyr kinase A (TrkA), which is known to bind to APP, fails to interact with the fraction of APP molecules phosphorylated at T668 (APP(pT668) ). Accordingly, the amount of TrkA bound to APP is significantly reduced in the hippocampus of ShcC KO mice and of patients with AD in which elevated APP(pT668) levels are detected. NGF promotes TrkA binding to APP and APP trafficking to the Golgi, where APP-BACE interaction is hindered, finally resulting in reduced generation of sAPPß, CTFß and amyloid-beta (1-42). These results demonstrate that NGF signalling directly controls basal APP phosphorylation, subcellular localization and BACE cleavage, and pave the way for novel approaches specifically targeting ShcC signalling and/or the APP-TrkA interaction in AD therapy.
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Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Factor de Crecimiento Nervioso/farmacología , Fosfotreonina/metabolismo , Adulto , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Animales , Ácido Aspártico Endopeptidasas/metabolismo , Activación Enzimática/efectos de los fármacos , Eliminación de Gen , Aparato de Golgi/efectos de los fármacos , Aparato de Golgi/metabolismo , Hipocampo/patología , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Células PC12 , Fosforilación/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Ratas , Receptor trkA/metabolismo , Proteína Transformadora 3 que Contiene Dominios de Homología 2 de Src/metabolismoRESUMEN
Alliance Against Cancer (ACC) was established in Rome in 2002 as a consortium of six Italian comprehensive cancer centers (Founders). The aims of ACC were to promote a network among Italian oncologic institutions in order to develop specific, advanced projects in clinical and translational research. During the following years, many additional full and associate members joined ACC, that presently includes the National Institute of Health, 17 research-oriented hospitals, scientific and patient organizations. Furthermore, in the last three years ACC underwent a reorganization process that redesigned the structure, governance and major activities. The present goal of ACC is to achieve high standards of care across Italy, to implement and harmonize principles of modern personalized and precision medicine, by developing cost effective processes and to provide tailored information to cancer patients. We herein summarize some of the major initiatives that ACC is currently developing to reach its goal, including tumor genetic screening programs, establishment of clinical trial programs for cancer patients treated in Italian cancer centers, facilitate their access to innovative drugs under development, improve quality through an European accreditation process (European Organization of Cancer Institutes), and develop international partnerships. In conclusion, ACC is a growing organization, trying to respond to the need of networking in Italy and may contribute significantly to improve the way we face cancer in Europe.
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Investigación Biomédica , Instituciones Oncológicas/organización & administración , Neoplasias/patología , Neoplasias/terapia , Humanos , Italia , Medicina de PrecisiónRESUMEN
One of the major limitations of flow cytometry (FCM) is the absence of an intracellular view. Automated microscopy and image analysis, together with technological developments, led to new approaches in cytometry that bypass the above limitation, introducing high resolution, high content, and large statistical sampling. However, few attempts have been made, until now, to translate the wide repertoire of FCM assays into high-content image screening. This unit describes the implementation of an acquisition and analysis protocol for evaluation of the cell cycle by automated microscopy. The approach grants the possibility to perform simultaneous analysis of a high number of different parameters. A large part of this unit is devoted to the description of hardware features that can optimize the recorded information together with the acquisition and analysis procedures employed to produce good-quality data.
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Automatización , Ciclo Celular , Procesamiento de Imagen Asistido por Computador , Microscopía , Animales , Automatización/instrumentación , Automatización/métodos , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , Procesamiento de Imagen Asistido por Computador/métodos , Microscopía/instrumentación , Microscopía/métodosRESUMEN
Optical fluorescence microscopy offers a wide range of technological solutions to address many questions in biomedical research. Spatial resolution has been greatly improved by the use of confocal microscopes, providing a 3-D analysis of the intracellular space. Automation has contributed to make confocal analysis available for high-content image cytometry studies. However, the storage, browsing, and analysis of the amount of data generated can challenge the feasibility of such studies. Presented in this chapter is a multistep acquisition and analysis protocol that can bypass such difficulties by an analysis-driven data collection. Cell-cycle analysis of low-resolution data can be employed to select cell populations of interest that can then be imaged at extremely high resolution and subjected to high-content analysis.
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Ciclo Celular , Imagenología Tridimensional/instrumentación , Imagenología Tridimensional/métodos , Animales , Humanos , Microscopía Confocal/instrumentación , Microscopía Confocal/métodos , Microscopía Fluorescente/instrumentación , Microscopía Fluorescente/métodosRESUMEN
BACKGROUND: Bronchopleural fistula after lung resection still represents a challenging life-threatening complication for thoracic surgeons. Considering its extremely high mortality rate, an effective treatment is urgently required. Our project investigated the hypothesis of experimental bronchopleural fistula closure by bronchoscopic injection of autologous bone marrow-derived mesenchymal stem cells into the cavity of the fistula, evaluating its feasibility and safety in a large animal model. METHODS: An experimental bronchopleural fistula was created in 9 goats after right upper tracheal lobectomy. The animals were randomly assigned to two groups: one received autologous bone marrow-derived mesenchymal stem cell bronchoscopic transplantation; the other received standard bronchoscopic fibrin glue injection. RESULTS: All animals receiving bronchoscopic stem cell transplantation presented fistula closure by extraluminal fibroblast proliferation and collagenous matrix development; none (0%) died during the study period. All animals receiving standard treatment still presented bronchopleural fistula; 2 of them (40%) died. Findings were confirmed by pathology examination, computed tomography, and magnetic resonance imaging. CONCLUSIONS: Bronchoscopic transplantation of bone marrow-derived mesenchymal stem cells effectively closes experimental bronchopleural fistula by extraluminal fibroblast proliferation and collagenous matrix development. Stem cells may play a crucial role in the treatment of postresectional bronchopleural fistula after standard lung resection. Although these results provide a basis for the development of clinical therapeutic strategies, the exact mechanism by which they are obtained is not yet completely clear; further studies are required to understand exactly how stem cells work in this field.
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Fístula Bronquial/cirugía , Enfermedades Pleurales/cirugía , Fístula del Sistema Respiratorio/cirugía , Trasplante de Células Madre , Animales , Modelos Animales de Enfermedad , Femenino , Cabras , Inducción de RemisiónRESUMEN
Diabetes compromises the bone marrow (BM) microenvironment and reduces the number of circulating CD34(+) cells. Diabetic autonomic neuropathy (DAN) may impact the BM, because the sympathetic nervous system is prominently involved in BM stem cell trafficking. We hypothesize that neuropathy of the BM affects stem cell mobilization and vascular recovery after ischemia in patients with diabetes. We report that, in patients, cardiovascular DAN was associated with fewer circulating CD34(+) cells. Experimental diabetes (streptozotocin-induced and ob/ob mice) or chemical sympathectomy in mice resulted in BM autonomic neuropathy, impaired Lin(-)cKit(+)Sca1(+) (LKS) cell and endothelial progenitor cell (EPC; CD34(+)Flk1(+)) mobilization, and vascular recovery after ischemia. DAN increased the expression of the 66-kDa protein from the src homology and collagen homology domain (p66Shc) and reduced the expression of sirtuin 1 (Sirt1) in mice and humans. p66Shc knockout (KO) in diabetic mice prevented DAN in the BM, and rescued defective LKS cell and EPC mobilization. Hematopoietic Sirt1 KO mimicked the diabetic mobilization defect, whereas hematopoietic Sirt1 overexpression in diabetes rescued defective mobilization and vascular repair. Through p66Shc and Sirt1, diabetes and sympathectomy elevated the expression of various adhesion molecules, including CD62L. CD62L KO partially rescued the defective stem/progenitor cell mobilization. In conclusion, autonomic neuropathy in the BM impairs stem cell mobilization in diabetes with dysregulation of the life-span regulators p66Shc and Sirt1.
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Médula Ósea/fisiopatología , Neuropatías Diabéticas/fisiopatología , Movilización de Célula Madre Hematopoyética , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Sirtuina 1/biosíntesis , Anciano , Animales , Células Cultivadas , Diabetes Mellitus Experimental/fisiopatología , Regulación hacia Abajo , Femenino , Humanos , Leucocitos Mononucleares/metabolismo , Masculino , Ratones , Persona de Mediana Edad , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
Reactive oxygen species (ROS), mainly originated from mitochondrial respiration, are critical inducers of oxidative damage and involved in tissue dysfunction. It is not clear, however, whether oxidative stress is the result of an active gene program or it is the by-product of physiological processes. Recent findings demonstrate that ROS are produced by mitochondria in a controlled way through specialized enzymes, including p66Shc, and take part in cellular process aimed to ensure adaptation and fitness. Therefore, genes generating specifically ROS are selected determinants of life span in response to different environmental conditions.
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Mitocondrias Hepáticas/efectos de los fármacos , Especies Reactivas de Oxígeno/agonistas , Proteínas Adaptadoras de la Señalización Shc/farmacología , Animales , Apoptosis/efectos de los fármacos , Regulación de la Temperatura Corporal/fisiología , Ciclosporina/farmacología , Técnicas Electroquímicas , Escherichia coli/genética , Escherichia coli/metabolismo , Etilmaleimida/farmacología , Humanos , Ratones , Mitocondrias Hepáticas/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/antagonistas & inhibidores , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , Oxidación-Reducción , Estrés Oxidativo , Isoformas de Proteínas/biosíntesis , Isoformas de Proteínas/genética , Isoformas de Proteínas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/genética , Transducción de Señal , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
Mitochondrial-mediated oxidative stress and apoptosis play a crucial role in neurodegenerative disease and aging. Both mitochondrial permeability transition (PT) and swelling of mitochondria have been involved in neurodegeneration. Indeed, knockout mice for cyclophilin-D (Cyc-D), a key regulatory component of the PT pore (PTP) that triggers mitochondrial swelling, resulted to be protected in preclinical models of multiple sclerosis (MS), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). However, how neuronal stress is transduced into mitochondrial oxidative stress and swelling is unclear. Recently, the aging determinant p66Shc that generates H2O2 reacting with cytochrome c and induces oxidation of PTP and mitochondrial swelling was found to be involved in MS and ALS. To investigate the role of p66Shc/PTP pathway in neurodegeneration, we performed experimental autoimmune encephalomyelitis (EAE) experiments in p66Shc knockout mice (p66Shc-/-), knock out mice for cyclophilin-D (Cyc-D-/-), and p66Shc Cyc-D double knock out (p66Shc/Cyc-D-/-) mice. Results confirm that deletion of p66Shc protects from EAE without affecting immune response, whereas it is not epistatic to the Cyc-D mutation. These findings demonstrate that p66Shc contributes to EAE induced neuronal damage most likely through the opening of PTP suggesting that p66Shc/PTP pathway transduces neurodegenerative stresses.
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Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Degeneración Nerviosa/metabolismo , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Animales , Apoptosis , Línea Celular , Peptidil-Prolil Isomerasa F , Ciclofilinas/deficiencia , Ciclofilinas/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/patología , Ensayo de Inmunoadsorción Enzimática , Eliminación de Gen , Humanos , Ratones , Ratones Noqueados , Poro de Transición de la Permeabilidad Mitocondrial , Degeneración Nerviosa/patología , Neuronas/metabolismo , Neuronas/patología , Ratas , Proteínas Adaptadoras de la Señalización Shc/deficiencia , Médula Espinal/metabolismo , Médula Espinal/patología , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
A panel of experts from Italian Comprehensive Cancer Centers defines the recommendations for external quality control programs aimed to accreditation to excellence of these institutes. After definition of the process as a systematic, periodic evaluation performed by an external agency to verify whether a health organization possesses certain prerequisites regarding structural, organizational and operational conditions that are thought to affect health care quality, the panel reviews models internationally available and makes final recommendations on aspects considered of main interest. This position paper has been produced within a special project of the Ministry of Health of the Italian Government aimed to accredit, according to OECI model, 11 Italian cancer centers in the period 2012-2014. The Project represents the effort undertaken by this network of Comprehensive Cancer Centers to find a common denominator for the experience of all Institutes in external quality control programs. Fourteen shared "statements" are put forth, designed to offer some indications on the main aspects of this subject, based on literature evidence or expert opinions. They deal with the need for "accountability" and involvement of the entire organization, the effectiveness of self-evaluation, the temporal continuity and the educational value of the experience, the use of indicators and measurement tools, additionally for intra- and inter-organization comparison, the system of evaluation models used, the provision for specific requisites for oncology, and the opportunity for mutual exchange of evaluation experiences.
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Acreditación , Benchmarking , Investigación Biomédica , Instituciones Oncológicas/normas , Calidad de la Atención de Salud , Investigación Biomédica/organización & administración , Investigación Biomédica/normas , Investigación Biomédica/tendencias , Competencia Clínica , Vías Clínicas , Agencias Gubernamentales , Personal de Salud , Humanos , Capacitación en Servicio , Internacionalidad , Italia , Revisión por Pares , Control de Calidad , Investigadores , Responsabilidad SocialRESUMEN
Although epigenetic drugs have been approved for use in selected malignancies, there is significant need for a better understanding of their mechanism of action. Here, we study the action of a clinically approved DNA-methyltransferase inhibitor - decitabine (DAC) - in acute myeloid leukemia (AML) cells. At low doses, DAC treatment induced apoptosis of NB4 Acute Promyelocytic Leukemia (APL) cells, which was associated with the activation of the extrinsic apoptotic pathway. Expression studies of the members of the Death Receptor family demonstrated that DAC induces the expression of TNF-related apoptosis-inducing ligand (TRAIL). Upregulation of TRAIL, upon DAC treatment, was associated with specific epigenetic modifications induced by DAC in the proximity of the TRAIL promoter, as demonstrated by DNA demethylation, increased DNaseI sensitivity and histone acetylation of a non-CpG island, CpG-rich region located 2kb upstream to the transcription start site. Luciferase assay experiments showed that this region behave as a DNA methylation sensitive transcriptional regulatory element. The CpG regulatory element was also found methylated in samples derived from APL patients. These findings have been confirmed in the non-APL, AML Kasumi cell line, suggesting that this regulatory mechanism may be extended to other AMLs. Our study suggests that DNA methylation is a regulatory mechanism relevant for silencing of the TRAIL apoptotic pathway in leukemic cells, and further elucidates the mechanism by which epigenetic drugs mediate their anti-leukemic effects.
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Apoptosis/efectos de los fármacos , Azacitidina/análogos & derivados , Inhibidores de Histona Desacetilasas/farmacología , Leucemia Mieloide Aguda/fisiopatología , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Azacitidina/farmacología , Línea Celular Tumoral , Metilación de ADN/efectos de los fármacos , Decitabina , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Regiones Promotoras Genéticas , Transducción de Señal/efectos de los fármacos , Ligando Inductor de Apoptosis Relacionado con TNF/genéticaRESUMEN
Reactive oxygen species (ROS) are regarded as hazardous by-products of mitochondrial respiration. In addition to the respiratory chain, specific ROS-generating systems have evolved. In particular, p66Shc is a mitochondrial redox protein that oxidizes cytochrome c to generate H2O2. Consistently, the deletion of p66Shc in cells and tissue results in reduced levels of ROS and oxidative stress. Taking advantage of the p66Shc knock out (p66KO) mouse model of decreased ROS production, we assessed the role of endogenously-produced ROS in tumorigenesis. Spontaneous tumor incidence was investigated and found unaltered in two different strains, 129Sv and C57Bl/6J, p66KO mice. In addition, papilloma formation upon exposure to ultraviolet radiation (UV) or 7,12-Dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol- 13-acetate (DMBA/TPA) was found to be slightly lower in the absence of p66Shc. The role of p66Shc in tumorigenesis was also investigated in the absence of the tumor suppressor gene p53 (p53KO) by generating p53-p66Shc double knock out (DKO) mice. Notably, DKO mice displayed a significantly increased lifespan compared to p53KO mice. In addition, 2-deoxy-2-(18F)fluoro-D-glucose Positron Emission Tomography ([18F]FDG PET) analysis allowed to determine that disease onset occurred later in life in DKO mice compared to p53KO and that a low percentage of these mice did not develop tumors. Overall, these results indicate that although tumor incidence is not decreased in p66KO mice, p66Shc contributes to tumor initiation, in particular upon activation by carcinogens as well as when p53- mediated tumor suppression mechanisms defect.
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Apoptosis , Transformación Celular Neoplásica , Estrés Oxidativo , Proteínas Adaptadoras de la Señalización Shc/fisiología , Proteína p53 Supresora de Tumor/fisiología , 9,10-Dimetil-1,2-benzantraceno/toxicidad , Animales , Carcinógenos/toxicidad , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Acetato de Tetradecanoilforbol/toxicidad , Rayos UltravioletaRESUMEN
Although intrinsic apoptosis defects are causal to the extended survival of chronic lymphocytic leukemia (CLL) B cells, several lines of evidence support a contribution of the peripheral lymphoid organs and BM microenvironment to the extended lifespan of leukemic B cells. Lymphocyte trafficking is controlled by homing signals provided by stromal cell-derived chemokines and egress signals provided by sphingosine-1-phosphate (S1P). In the present study, we show that expression of S1P1, the S1P receptor responsible for lymphocyte egress, is selectively reduced in CLL B cells with unmutated IGHV. Expression of S1P2, which controls B-cell homeostasis, is also impaired in CLL B cells but independently of the IGHV mutational status. We provide evidence herein that p66Shc, a Shc adaptor family member the deficiency of which is implicated in the apoptosis defects of CLL B cells, controls S1P1 expression through its pro-oxidant activity. p66Shc also controls the expression of the homing receptor CCR7, which opposes S1P1 by promoting lymphocyte retention in peripheral lymphoid organs. The results of the present study provide insights into the regulation of S1P1 expression in B cells and suggest that defective egress caused by impaired S1P1 expression contributes to the extended survival of CLL B cells by prolonging their residency in the prosurvival niche of peripheral lymphoid organs.
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Leucemia Linfocítica Crónica de Células B/diagnóstico , Leucemia Linfocítica Crónica de Células B/genética , Receptores de Lisoesfingolípidos/genética , Proteínas Adaptadoras de la Señalización Shc/fisiología , Adulto , Animales , Femenino , Regulación de la Expresión Génica/genética , Regulación Leucémica de la Expresión Génica , Humanos , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/mortalidad , Masculino , Ratones , Ratones Noqueados , Oxidantes/metabolismo , Pronóstico , Receptores de Lisoesfingolípidos/fisiología , Proteínas Adaptadoras de la Señalización Shc/genética , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Células Tumorales CultivadasRESUMEN
Longevity of a p66Shc knockout strain (ShcP) was previously attributed to increased stress resistance and altered mitochondria. Microarrays of ShcP tissues indicated alterations in insulin signaling. Consistent with this observation, ShcP mice were more insulin sensitive and glucose tolerant at organismal and tissue levels, as was a novel p66Shc knockout (ShcL). Increasing and decreasing Shc expression in cell lines decreased and increased insulin sensitivity, respectively - consistent with p66Shc's function as a repressor of insulin signaling. However, differences between the two p66Shc knockout strains were also observed. ShcL mice were fatter and susceptible to fatty diets, and their fat was more insulin sensitive than controls. On the other hand, ShcP mice were leaner and resisted fatty diets, and their adipose was less insulin sensitive than controls. ShcL and ShcP strains are both highly inbred on the C57Bl/6 background, so we investigated gene expression at the Shc locus, which encodes three isoforms, p66, p52, and p46. Isoform p66 is absent in both strains; thus, the remaining difference to which to attribute the 'lean' phenotype is expression of the other two isoforms. ShcL mice have a precise deletion of p66Shc and normal expression of p52 and p46Shc isoforms in all tissues; thus, a simple deletion of p66Shc results in a 'fat' phenotype. However, ShcP mice in addition to p66Shc deletion have a fourfold increase in p46Shc expression in white fat. Thus, p46Shc overexpression in fat, rather than p66Shc deletion, is the likely cause of decreased adiposity and reduced insulin sensitivity in the fat of ShcP mice, which has implications for the longevity of the strain.
Asunto(s)
Adiposidad/genética , Insulina/metabolismo , Isoformas de Proteínas/genética , Proteínas Adaptadoras de la Señalización Shc/genética , Transducción de Señal/fisiología , Animales , Células Cultivadas , Grasas de la Dieta/metabolismo , Femenino , Sitios Genéticos/fisiología , Glucosa/metabolismo , Resistencia a la Insulina/genética , Longevidad/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Análisis de Secuencia por Matrices de Oligonucleótidos , Estrés Oxidativo/genética , Isoformas de Proteínas/metabolismo , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Delgadez/genética , Delgadez/metabolismoRESUMEN
In patients with ST-segment elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI), abrupt reperfusion can induce myocardial injury and apoptotic cell death. Reperfusion-induced myocardial damage, however, cannot be easily evaluated in clinical practice because of the lack of specific biomarkers. Cytochrome c, a mitochondrial protein, is released on reperfusion into the cytosol, where it triggers the apoptotic process. It can reach the external fluid and circulating blood when cell rupture occurs. We measured the cytochrome c circulating levels in patients with STEMI undergoing pPCI, and correlated them with the clinical signs of myocardial necrosis and reperfusion. The plasma creatine kinase-MB mass and serum cytochrome c (enzyme-linked immunosorbent assay method) were serially measured in 55 patients with STEMI undergoing pPCI. The angiographic and electrocardiographic signs of myocardial reperfusion were also assessed. Cytochrome c transiently increased in all patients with STEMI, with a curve that paralleled that of creatine kinase-MB. A significant relation was found between the peak values of the 2 biomarkers (R = 0.35, p = 0.01) and between the areas under the 2 curves (R = 0.33, p = 0.02). The creatine kinase-MB peak value correlated significantly with the clinical features of infarct extension. In contrast, the cytochrome c peak value correlated inversely with the myocardial blush grade. Patients with clinical signs of myocardial reperfusion injury had a significantly greater cytochrome c peak value than patients without reperfusion injury (median 1.65 ng/ml, interquartile range 1.20 to 2.20, vs 1.1 ng/ml, interquartile range 0.65 to 1.55; p = 0.04). In conclusion, serum cytochrome c is detectable in the early phase of STEMI treated with pPCI and is associated with clinical signs of impaired myocardial reperfusion.