RESUMEN
Intellectual disability (ID) is a neurodevelopmental disorder characterized by limitations in both intellectual and behavioral functioning. It can occur in non-syndromic and syndromic forms involving multiple organs. While the majority of genetic variants linked to ID are de novo, inherited variants are also detected in some forms. Here, we report a consanguineous Lebanese family presenting with an autosomal recessive syndromic ID characterized by neurodevelopmental delay, mild dysmorphic features, hearing impairment and endocrine dysfunction. Whole exome sequencing enabled the detection of the homozygous nonsense mutation in BOD1, p.R151X, in the proband. BOD1 is required for chromosomes biorientation during cell division. It also contributes to the regulation of cell survival and to the modulation of fatty acid metabolism. Another nonsense mutation in BOD1 was linked to ID in a consanguineous Iranian family. This is the second report of BOD1 mutations in humans and the first in a syndromic ID including gonadal dysfunction and high-frequency hearing impairment. Our findings confirm the involvement of BOD1 in cognitive functioning and expand the clinical spectrum of BOD1 deficiency.
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Proteínas de Ciclo Celular/genética , Predisposición Genética a la Enfermedad , Discapacidad Intelectual/genética , Adolescente , Niño , Cromosomas/genética , Codón sin Sentido/genética , Consanguinidad , Humanos , Discapacidad Intelectual/patología , Masculino , Linaje , Secuenciación del ExomaRESUMEN
OBJECTIVES: To study the effect of red blood cell (RBC) storage duration on long-term mortality in patients undergoing cardiac intervention. BACKGROUND: RBCs undergo numerous structural and functional changes during storage. Observational studies have assessed the association between RBC storage duration and patient outcomes with conflicting results. METHODS: Between January 2006 and December 2014, 82 408 patients underwent coronary angiography. Of these, 1856 patients received one to four RBC units within 30 days after this procedure. Patients were allocated according to length of RBC storage duration: short-term (≤11 days), intermediate (IM)-term (12-23 days) and long-term (≥24 days). The study endpoints were 30-day and long-term all-cause mortality. RESULTS: A total of 4168 RBC units were given to 1856 patients. The mean RBC storage duration was 8.5 ± 2.1, 17.7 ± 3.4 and 29.9 ± 3.4 days in the short-term, IM-term and long-term storage groups, respectively. There was no difference in baseline characteristics between the groups. The long-term storage group received significantly more units (2.4 ± 1.0 units) as compared to the short-term (2.0 ± 1.0 units; P < 0.001) and IM-term storage group (2.2 ± 1.0 units; P < 0.01). In the survival analysis, there was no significant difference in all-cause mortality between the groups (log-rank: 0.509 for 30-days mortality; 0.493 for 5-year mortality). Additional stratified analysis demonstrated no association between RBC storage duration and long-term mortality. CONCLUSION: This study did not find an association between RBC storage duration and 30-days or long-term mortality in patients undergoing cardiac intervention.
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Conservación de la Sangre/efectos adversos , Angiografía Coronaria/mortalidad , Transfusión de Eritrocitos/mortalidad , Eritrocitos , Anciano , Anciano de 80 o más Años , Dinamarca , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Estudios Retrospectivos , Factores de TiempoRESUMEN
AIM: to describe the procedural steps and to report the short term follow up of our initial experience with an axillarian bareback Dacron graft based technique that could potentially reduce the rate of vascular and ischemic complications during transcatheter aortic valve implantation in patients with contraindications to trans-femoral approach and with patent left internal mammary arterial graft to left anterior descending coronary artery (LIMA-LAD) or small caliber axillarian/subclavian arteries. METHODS AND RESULTS: Four patients were treated with TAVI implantation with a trans axillarian bareback approach. Three out of four had a patent LIMA-LAD graft. In three patients, femoral approach was not considered as an option for the presence of diffuse peripheral vascular disease, while in one for the small caliber of iliac-femoral arteries. All procedures were performed under general anaesthesia. No procedural complications occurred. CONCLUSIONS: In this initial experience, the axillarian bareback approach technique allowed a safe and successful TAVI implant in a subgroup of patients with a high risk of procedural complications due to the presence of a patent LIMA-LAD or vessels of small caliber. Considering the increasing number of patients referred for TAVI, in the next future the axillarian bareback approach could represent a safer alternative to direct cannulation in patients with severe aortic stenosis with no other access options.
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Estenosis de la Válvula Aórtica/terapia , Axila , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Anciano , Anciano de 80 o más Años , Comorbilidad , Femenino , Humanos , Masculino , Resultado del TratamientoRESUMEN
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. One of its most devastating complications is the development of thromboembolism leading to fatal or disabling stroke. Oral anticoagulation (OAC, warfarin) is the standard treatment for stroke prevention in patients with AF with an increased stroke risk. However, there are several obstacles to long-term OAC therapy, including the risk of serious bleeding, several drug-drug interactions and the need for frequent blood testing. Although newer oral anticoagulants have been developed, these drugs also face issues of major bleeding and non-compliance. Therefore, alternative treatment options for stroke prevention in patients with AF with a high stroke risk are needed. Percutaneous left atrial appendage (LAA) occlusion is an evolving therapy, which should be taken into consideration in those patients with non-valvular AF with a high stroke risk and contraindications for OAC. This article aims to discuss the rationale for LAA closure, the available LAA occlusion devices and their clinical evidence until now. Moreover, we discuss the importance of proper patient selection, the role of various imaging techniques and the need for a more tailored postprocedural antithrombotic therapy.
RESUMEN
In this report, we describe a case of Tako-Tsubo cardiomyopathy (TTC)--also called 'apical ballooning' syndrome--in which transient left ventricular outflow tract (LVOT) obstruction and mitral regurgitation led to haemodynamic instability. Patients with hypotension should undergo urgent echocardiography to determine if LVOT obstruction is present. This complication has been described in 10-25% of all TTC patients. In patients with hypotension and moderate-to-severe LVOT obstruction, inotropic agents should not be used because they can worsen the degree of obstruction. Instead, it is suggested to use beta-blockers, which can improve haemodynamics by causing resolution of the obstruction. The fact that some patients do not survive their acute TTC event only underscores the importance of prompt recognition and targeted management of dynamic LVOT obstruction.
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Cardiomiopatía de Takotsubo/complicaciones , Obstrucción del Flujo Ventricular Externo/complicaciones , Anciano , Electrocardiografía , Femenino , Humanos , Hipotensión/etiología , Insuficiencia de la Válvula Mitral/complicaciones , Volumen Sistólico , Cardiomiopatía de Takotsubo/fisiopatología , Cardiomiopatía de Takotsubo/terapia , Obstrucción del Flujo Ventricular Externo/fisiopatologíaRESUMEN
Damage to DNA has emerged as a major culprit in cancer. Mammalian cells are continuously exposed to DNA damage, caused by exogenous toxins as well as endogenous activities such as DNA replication and cellular free radical generation. It is therefore essential that cells have DNA repair mechanisms in place to preserve its genomic integrity. Interestingly, cancer cells frequently harbour defects in DNA repair pathways, leading to genomic instability. This can foster tumorigenesis, but also provides a weakness in the tumour that can be exploited therapeutically. In this context, it has been shown that homologous recombination (HR)-deficient tumour cells--including those with defects in BRCA1/2--are highly sensitive to blockade of the base excision repair (BER) pathway via inhibition of the poly (ADP-ribose) polymerase (PARP) enzyme. This provides the basis for a novel 'synthetic lethal' approach to cancer therapy. Recent clinical trials have shown an enhancement of the cytotoxic effect of chemotherapy by adding a PARP inhibitor to the standard treatment. Still, clinical outcome may be even further improved if these drugs would be used as first-line therapy. In conclusion, it can be stated that an exciting new class of drugs has entered the arena of cancer therapy. However, additional clinical studies are needed before PARP inhibitors can definitely enter daily clinical practice.
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Daño del ADN/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Benzamidas/uso terapéutico , Bencimidazoles/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Ensayos Clínicos como Asunto , Reparación del ADN/efectos de los fármacos , Reparación del ADN/fisiología , Femenino , Genes BRCA1/fisiología , Genes BRCA2/fisiología , Mutación de Línea Germinal , Humanos , Neoplasias/genética , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Ftalazinas/uso terapéutico , Piperazinas/uso terapéuticoRESUMEN
BACKGROUND AND AIMS: Treatment with carbon monoxide (CO) inhalation has been shown to ameliorate postoperative ileus (POI) in rodents and swine. The aim of this study was to investigate whether CO liberated from water-soluble CO-releasing molecules (CO-RMs) can protect against POI in mice and to elucidate the mechanisms involved. METHODS: Ileus was induced by surgical manipulation of the small intestine (IM). Intestinal contractility-transit was evaluated by video-fluorescence imaging. Leucocyte infiltration (myeloperoxidase), inflammatory parameters (ELISA), oxidative stress (lipid peroxidation), and haem oxygenase (HO)/inducible nitric oxide synthase (iNOS) enzyme activity were measured in the intestinal mucosa and muscularis propria. RESULTS: Intestinal contractility and transit were markedly restored when manipulated mice were pre-treated with CO-RMs. Intestinal leucocyte infiltration, expression levels of interleukin 6 (IL6), monocyte chemoattractant protein-1 and intercellular adhesion molecule-1, as well as iNOS activity were reduced by treatment with CORM-3 (a transition metal carbonyl that releases CO very rapidly); whereas expression of IL10/HO-1 was further increased when compared to nontreated manipulated mice. Moreover, treatment with CORM-3 markedly reduced oxidative stress and extracellular signal-related kinase (ERK)1/2 activation in both mucosa (early response) and muscularis (biphasic response). The p38 mitogen-activated protein kinase inhibitor SB203580 abolished CORM-3-mediated HO-1 induction. The HO inhibitor chromium mesoporphyrin only partially reversed the protective effects of CORM-3 on inflammation/oxidative stress in the muscularis, but completely abrogated CORM-3-mediated inhibition of the early "oxidative burst" in the mucosa. CONCLUSIONS: Pre-treatment with CO-RMs markedly reduced IM-induced intestinal muscularis inflammation. These protective effects are, at least in part, mediated through induction of HO-1, in a p38-dependent manner, as well as reduction of ERK1/2 activation. In addition, CORM-induced HO-1 induction reduces the early "oxidative burst" in the mucosa following IM.
Asunto(s)
Monóxido de Carbono/administración & dosificación , Hemo-Oxigenasa 1/biosíntesis , Ileus/prevención & control , Intestino Delgado , Estrés Oxidativo/efectos de los fármacos , Complicaciones Posoperatorias/prevención & control , Administración por Inhalación , Animales , Carboxihemoglobina/metabolismo , Tránsito Gastrointestinal/fisiología , Hemo-Oxigenasa 1/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa de Tipo II/metabolismo , Distribución Aleatoria , Transducción de SeñalRESUMEN
NRAGE (also known as Maged1, Dlxin) is a member of the MAGE gene family that may play a role in the neuronal apoptosis that is regulated by the p75 neurotrophin receptor (p75NTR). To test this hypothesis in vivo, we generated NRAGE knockout mice and found that NRAGE deletion caused a defect in developmental apoptosis of sympathetic neurons of the superior cervical ganglia, similar to that observed in p75NTR knockout mice. Primary sympathetic neurons derived from NRAGE knockout mice were resistant to apoptosis induced by brain-derived neurotrophic factor (BDNF), a pro-apoptotic p75NTR ligand, and NRAGE-deficient sympathetic neurons show attenuated BDNF-dependent JNK activation. Hair follicle catagen is an apoptosis-like process that is dependent on p75NTR signaling; we show that NRAGE and p75NTR show regulated co-expression in the hair follicle and that identical defects in hair follicle catagen are present in NRAGE and p75NTR knockout mice. Interestingly, NRAGE knockout mice have severe defects in motoneuron apoptosis that are not observed in p75NTR knockout animals, raising the possibility that NRAGE may facilitate apoptosis induced by receptors other than p75NTR. Together, these studies demonstrate that NRAGE plays an important role in apoptotic-signaling in vivo.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Apoptosis , Proteínas de Neoplasias/metabolismo , Receptor de Factor de Crecimiento Nervioso/metabolismo , Animales , Fertilidad , Marcación de Gen , Folículo Piloso/crecimiento & desarrollo , Folículo Piloso/patología , Ratones , Ratones Noqueados , Neuronas Motoras/citología , Mutación/genética , Proteínas de Neoplasias/deficiencia , Sistema Nervioso Simpático/citología , Ganglio del Trigémino/anomalíasRESUMEN
This study introduces a novel, simplified method for the evaluation of murine intestinal transit and contractility using fluorescence and video imaging. Intestinal transit was measured by evaluating the intestinal distribution of non-absorbable fluorescein-labelled dextran (70 kDa, FD70) along the gastrointestinal (GI) tract. After excision of the GI tract, two full-field images--one in normal illumination mode and another in fluorescent mode--were taken with a charge coupled device (CCD) camera and subsequently matched for calculation of fluorescence distribution along the GI tract. Immediately after, intestinal contractility was evaluated in different regions of the intact intestine by spatiotemporal motility mapping (i.e. video imaging). In control mice, the small intestine showed vigorous oscillatory contractions and FD70 was primarily distributed within the terminal ileum/caecum at 90 min postgavage. As validation step, the effect of intestinal manipulation (IM, surgical procedure) and two pharmacological agents--known to alter GI motility--was tested. At 24 h postoperatively, spontaneous contractile activity of the small intestine was nearly abolished in IM mice, leaving the small intestine distended and resulting in a significantly delayed intestinal transit. In accordance, spontaneous mechanical activity of circular muscle strips in standard organ baths was significantly reduced in IM mice compared to control mice. Administration of atropine (1-3 mg kg(-1), i.p.) suppressed spontaneous contractile activity along the entire intestinal tract and induced a dose-related delay in intestinal transit. In contrast, metoclopramide (3-10 mg kg(-1), i.p.) markedly increased contractile activity--however only in the upper GI tract--and accelerated intestinal transit in a dose-dependent manner.
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Motilidad Gastrointestinal/fisiología , Tránsito Gastrointestinal/fisiología , Intestinos/fisiología , Administración Oral , Animales , Dextranos , Diagnóstico por Imagen/métodos , Fluoresceínas , Fluorescencia , Intestinos/química , Masculino , Ratones , Ratones Endogámicos C57BL , Técnicas de Cultivo de Órganos , Factores de TiempoRESUMEN
Celsr, also called Flamingo (Fmi) genes encode proteins of the cadherin superfamily. Celsr cadherins are seven-pass transmembrane proteins with nine cadherin repeats in the extracellular domain, and an anonymous intracellular C-terminus. The Drosophila Fmi gene regulates epithelial planar cell polarity and dendritic field deployment. The three Flamingo gene orthologs in man and rodents are named, respectively, CELSR1-3 and Celsr1-3. Celsr1 and 2 are expressed during early development, in the brain and epithelia. In this report, we characterized further Celsr genes in the mouse, and examined their developmental pattern of expression. Each Celsr is expressed prominently in the developing brain following a specific pattern, suggesting that they serve distinct functions.
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Encéfalo/embriología , Cadherinas/biosíntesis , Proteínas Fetales , Receptores de Superficie Celular/biosíntesis , Receptores Acoplados a Proteínas G , Animales , Encéfalo/metabolismo , Cadherinas/química , Cadherinas/genética , Cadherinas/metabolismo , Corteza Cerebral/metabolismo , Hibridación in Situ , Ratones , Modelos Genéticos , Estructura Terciaria de Proteína , Receptores de Superficie Celular/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo , Distribución TisularRESUMEN
BACKGROUND: Testicular germ cell tumors are the most common malignancy in young males, and the frequency of these tumors has risen dramatically over the last century. Because it is known that the MAGE genes are expressed in a wide variety of tumors but are expressed only in the mitotic spermatogonia (germ cells) and in the primary spermatocytes in the normal testis, the authors screened the expression of MAGE-A4 in a panel of testicular germ cell tumors. METHODS: Monoclonal antibody 57B raised against MAGE-A4 was tested immunohistochemically on 12 classical seminomas, 5 anaplastic seminomas, 10 various specimens of nonseminomatous germ cell tumors (NSGCTs), 2 combined tumors containing seminoma components, 1 Sertoli cell tumor, 2 Leydig cell tumors, and 15 carcinomas in situ (CIS). In addition, monoclonal antibody 57B was tested on embryonic gonad (age 8 weeks) and fetal gonads (ages 15 weeks, 17 weeks, and 28 weeks). RESULTS: Classical seminomas uniformly and specifically expressed MAGE-A4 compared with anaplastic seminomas and NSGCTs, which were negative for this antigen. Specific expression of MAGE-A4 also was seen in subpopulations of CIS cells, providing additional evidence for heterogeneity of the phenotype of these cells, in which it is believed that differentiation and proliferation generate seminomas and NSGCTs. Finally, MAGE-A4 was expressed in the fetal precursors of the stem germ cells from 17 weeks of gestation onward, in accordance the fact that CIS can arise from prespermatogonia in the fetus. CONCLUSIONS: MAGE-A4 can be considered a potential specific marker for normal premeiotic germ cells and germ cell tumors and can be used to characterize classical seminomas.
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Antígenos de Neoplasias/análisis , Biomarcadores de Tumor/análisis , Gónadas/metabolismo , Proteínas de Neoplasias , Neoplasias Testiculares/metabolismo , Testículo/metabolismo , Antígenos de Neoplasias/inmunología , Biomarcadores de Tumor/inmunología , Gónadas/embriología , Humanos , Inmunohistoquímica , Masculino , Pronóstico , Neoplasias Testiculares/diagnósticoRESUMEN
The first human members of the MAGE gene family that have been described are expressed in tumor cells but silent in normal adult tissues except in the male germ line. Hence, they encode strictly tumor-specific antigens that represent attractive targets for cancer immunotherapy. However, other members of the family were recently found to be expressed in normal cells, indicating that the family is larger and more disparate than initially expected. We therefore performed a database screening to identify all of the recorded members of both classes of human MAGE genes. This report provides an overview of the MAGE family and proposes a general nomenclature for all of the MAGE genes identified thus far. We found that the MAGE-D genes were particularly well conserved between man and mouse, suggesting that they exert important functions. In addition, the genomic structure of the MAGE-D genes indicates that one of them corresponds to the founder member of the family, and that all of the other MAGE genes are retrogenes derived from that common ancestral gene. Intriguingly, the COOH-terminal domain of MAGE-D3 was found to be identical to trophinin, a previously described protein believed to be involved in embryo implantation.
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Familia de Multigenes/genética , Proteínas de Neoplasias/genética , Secuencia de Aminoácidos , Animales , Cromosomas Humanos Par 15/genética , Cromosomas Humanos Par 3/genética , Bases de Datos Factuales , Femenino , Expresión Génica , Genes/genética , Humanos , Masculino , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Filogenia , ARN Mensajero/genética , ARN Mensajero/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Distribución Tisular , Cromosoma X/genéticaRESUMEN
The GAGE-1 gene was identified previously as a gene that codes for an antigenic peptide, YRPRPRRY, which was presented on a human melanoma by HLA-Cw6 molecules and recognized by a clone of CTLs derived from the patient bearing the tumor. By screening a cDNA library from this melanoma, we identified five additional, closely related genes named GAGE-2-6. We report here that further screening of this library led to the identification of two more genes, GAGE-7B and -8. GAGE-1, -2, and -8 code for peptide YRPRPRRY. Using another antitumor CTL clone isolated from the same melanoma patient, we identified antigenic peptide, YYWPRPRRY, which is encoded by GAGE-3, -4, -5, -6, and -7B and which is presented by HLA-A29 molecules. Genomic cloning of GAGE-7B showed that it is composed of five exons. Sequence alignment showed that an additional exon, which is present only in the mRNA of GAGE-1, has been disrupted in gene GAGE-7B by the insertion of a long interspersed repeated element retroposon. These GAGE genes are located in the p11.2-p11.4 region of chromosome X. They are not expressed in normal tissues, except in testis, but a large proportion of tumors of various histological origins express at least one of these genes. Treatment of normal and tumor cultured cells with a demethylating agent, azadeoxycytidine, resulted in the transcriptional activation of GAGE genes, suggesting that their expression in tumors results from a demethylation process.
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Antígenos de Neoplasias/genética , Melanoma/genética , Familia de Multigenes , Proteínas de Neoplasias/genética , Neoplasias/genética , Testículo/metabolismo , Secuencia de Aminoácidos , Animales , Antígenos de Neoplasias/biosíntesis , Antígenos de Neoplasias/química , Azacitidina/análogos & derivados , Azacitidina/farmacología , Secuencia de Bases , Células COS , Mapeo Cromosómico , Clonación Molecular , Decitabina , Exones , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Biblioteca de Genes , Humanos , Masculino , Datos de Secuencia Molecular , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/química , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Activación Transcripcional , Transfección , Células Tumorales Cultivadas , Cromosoma XRESUMEN
The human MAGE genes are expressed in a wide variety of tumors but not in normal cells, with the exception of the male germ cells, placenta, and, possibly, cells of the developing embryo. These genes encode tumor-specific antigens recognized by cytolytic T lymphocytes. The MAGE genes are located on the X chromosome, in three clusters denoted MAGE-A, B, and C, mapping at q28, p21.3, and q26, respectively. The function of these genes remains unknown. Because mice offer many advantages for the study of genes that may be involved in embryonic development, we looked for the murine equivalents of the 12 human MAGE-A genes. Using a MAGE-A probe, we isolated 8 new murine genes that are homologous to the MAGE genes. On average, the open reading frames (ORFs) of these 8 closely related genes display a slightly higher degree of nucleotide identity with the MAGE-A ORFs than with the MAGE-B or MAGE-C ORFs. Furthermore, like MAGE-A genes, they encode acidic proteins, whereas the MAGE-B genes encode basic proteins. Accordingly, these 8 murine genes were named Mage-a1 to 8 (approved symbols Magea1 to 8). Mage-a genes were mapped in two different loci on the mouse X chromosome. Mage-a4 and Mage-a7 are located in a region that is syntenic to either Xp21 or Xq28. The 6 other genes are arranged in a cluster located in a region syntenic to Xp22. Like their human counterparts, Mage-a genes were found to be transcribed in adult testis, but not in other tissues. Expression of some Mage-a genes was also detected in tumor cell lines. Two Mage-a genes were found to be expressed in blastocysts.
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Mapeo Cromosómico , Proteínas de Neoplasias/genética , Animales , Southern Blotting , Humanos , Endogamia , Masculino , Ratones , Datos de Secuencia Molecular , Familia de Multigenes , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Mapeo Restrictivo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/metabolismo , Testículo/metabolismo , Células Tumorales Cultivadas , Cromosoma XRESUMEN
It is now well established that human melanoma cells express antigens that are recognised by cytolytic T lymphocytes derived from the tumour-bearing patient. The molecular definition of these antigens is progressing at an accelerated pace. The currently characterised melanoma antigens can be classified into three categories: differentiation antigens, antigens encoded by genes that are specifically expressed in tumours, and antigens encoded by mutated genes. Several of these antigens are sufficiently tumour-specific to qualify them as candidate anti-cancer vaccines in melanoma patients.
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Antígenos de Neoplasias/genética , Genes , Melanoma/inmunología , Linfocitos T Citotóxicos/inmunología , Antígenos/genética , Antígenos de Diferenciación de Linfocitos T/genética , Humanos , Inmunoterapia , Melanoma/terapia , Mutación PuntualRESUMEN
Human gene MAGE-1 encodes tumor-specific antigens that are recognized on melanoma cells by autologous cytolytic T lymphocytes. This gene is expressed in a significant proportion of tumors of various histological types, but not in normal tissues except male germ-line cells. We reported previously that reporter genes driven by the MAGE-1 promoter are active not only in the tumor cell lines that express MAGE-1 but also in those that do not. This suggests that the critical factor causing the activation of MAGE-1 in certain tumors is not the presence of the appropriate transcription factors. The two major MAGE-1 promoter elements have an Ets binding site, which contains a CpG dinucleotide. We report here that these CpG are demethylated in the tumor cell lines that express MAGE-1, and are methylated in those that do not express the gene. Methylation of these CpG inhibits the binding of transcription factors, as seen by mobility shift assay. Treatment with the demethylating agent 5-aza-2'-deoxycytidine activated gene MAGE-1 not only in tumor cell lines but also in primary fibroblasts. Finally, the overall level of CpG methylation was evaluated in 20 different tumor cell lines. It was inversely correlated with the expression of MAGE-1. We conclude that the activation of MAGE-1 in cancer cells is due to the demethylation of the promoter. This appears to be a consequence of a genome-wide demethylation process that occurs in many cancers and is correlated with tumor progression.
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Antígenos de Neoplasias/biosíntesis , Antígenos de Neoplasias/genética , Genoma Humano , Melanoma/genética , Proteínas de Neoplasias , Neoplasias/genética , Transcripción Genética/efectos de los fármacos , Antineoplásicos/farmacología , Azacitidina/análogos & derivados , Azacitidina/farmacología , Secuencia de Bases , ADN/química , Metilasas de Modificación del ADN/antagonistas & inhibidores , Cartilla de ADN , Sondas de ADN , ADN de Neoplasias/química , Decitabina , Fosfatos de Dinucleósidos , Inhibidores Enzimáticos/farmacología , Humanos , Masculino , Melanoma/inmunología , Antígenos Específicos del Melanoma , Metilación , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , ARN Mensajero/biosíntesis , Linfocitos T Citotóxicos/inmunología , Células Tumorales CultivadasAsunto(s)
Antígenos de Neoplasias/genética , Regulación del Desarrollo de la Expresión Génica , Ratones/genética , Proteínas de Neoplasias , Espermátides/metabolismo , Espermatogénesis/genética , Animales , Antígenos de Neoplasias/biosíntesis , Diferenciación Celular , Humanos , Inmunoterapia/efectos adversos , Masculino , Melanoma/inmunología , Melanoma/terapia , Antígenos Específicos del Melanoma , Especificidad de la Especie , Espermátides/citología , Testículo/citologíaRESUMEN
Human melanoma MZ2-MEL expresses several distinct antigens that are recognized by autologous cytolytic T lymphocytes (CTL). Some of these antigens are encoded by genes MAGE-1, MAGE-3, and BAGE, which are expressed in a large fraction of tumors of various histological types but are silent in normal adult tissues with the exception of testis. We report here the identification of the gene coding for MZ2-F, another antigen recognized by autologous CTL on MZ2-MEL cells. This gene, which was named GAGE-1, is not related to any presently known gene. It belongs to a family of genes that are expressed in a variety of tumors but not in normal tissues, except for the testis. Antigenic peptide YRPRPRRY, which is encoded by GAGE-1, is recognized by anti-MZ2-F CTL on class I molecule HLA-Cw6. The two genes of the GAGE family that code for this peptide, namely GAGE-1 and GAGE-2, are expressed in a significant proportion of melanomas (24%), sarcomas (25%), non-small cell lung cancers (19%), head and neck tumors (19%), and bladder tumors (12%). About 50% of melanoma patients carry on their tumor at least one of the presently defined antigens encoded by the MAGE, BAGE, and GAGE genes.
Asunto(s)
Antígenos de Neoplasias/genética , Melanoma/inmunología , Familia de Multigenes , Proteínas de Neoplasias , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Animales , Antígenos de Neoplasias/biosíntesis , Antígenos de Neoplasias/inmunología , Secuencia de Bases , Línea Celular Transformada , Chlorocebus aethiops , ADN Complementario/genética , ADN de Neoplasias/genética , Epítopos/química , Epítopos/inmunología , Feto/metabolismo , Regulación Neoplásica de la Expresión Génica , Antígenos HLA-C/inmunología , Células HeLa , Humanos , Melanoma/genética , Antígenos Específicos del Melanoma , Datos de Secuencia Molecular , Neoplasias/inmunología , Especificidad de Órganos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Alineación de Secuencia , Homología de Secuencia , Transfección , Células Tumorales CultivadasRESUMEN
The human MAGE1 gene directs the expression of an antigen recognized on a melanoma by autologous cytolytic T lymphocytes. MAGE1 belongs to a family of genes that are expressed in a number of tumors of various histological types but not in normal tissues except testis. The MAGE genes are arranged in two groups that are located within two different regions of the human X chromosome (Xq26-qter and Xp21.3). By hybridizing mouse genomic libraries with a MAGE1 probe, we identified three homologous genes. Two of these mouse genes, Smage1 and Smage2, are more than 99% identical to each other and encode the same protein of 330 aa. The 5' noncoding region of Smage2 provides the potential for regulating the expression of the gene through several different promoters located in front of alternative first exons. The third gene, Smage3, has the structure of a processed transcript. It codes for a protein with only 11 aa substitutions with respect to the Smage1/2 product. Somatic cell hybrids and interspecific backcross analysis showed that Smage3 is autosomal and that Smage1 and Smage2 are located between the Dmd and the Ar loci on the mouse X chromosome. Since this region is syntenic to the human Xp21.1-p22.1 region, we conclude that Smage1 and Smage2 are homologous to the MAGE-Xp rather than to the MAGE-Xq genes. Smage1/2 transcripts were detected in several tumor and embryonal cell lines but not in normal mouse tissues with the exception of testis. Expression of Smage3 was found in embryos from Day 11 to Day 15.