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1.
Phys Med Biol ; 69(12)2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38830363

RESUMEN

Objective.Effective early treatment-within 3-5 months of disease onset-significantly improves rheumatoid arthritis (RA) prognosis. Nevertheless, 1 in 3 patients experiences treatment failure which takes 3-6 months to detect with current monitoring techniques. The aim of this work is to develop a method for extracting quantitative features from data obtained with time-domain diffuse optical imaging (TD-DOI), and demonstrate their sensitivity to RA disease activity.Approach.80 virtual phantoms of the proximal interphalangeal joint-obtained from a realistic tissue distribution derived from magnetic resonance imaging-were created to simulate RA-induced alterations in 5 physiological parameters. TD-DOI images were generated using Monte Carlo simulations, and Poisson noise was added to each image. Subsequently, each image was convolved with an instrument response function (IRF) to mimic experimental measurements. Various spatiotemporal features were extracted from the images (i.e. statistical moments, temporal Fourier components), corrected for IRF effects, and correlated with the disease index (DI) of each phantom.Main results.Spatiotemporal Fourier components of TD-DOI images were highly correlated with DI despite the confounding effects of noise and the IRF. Moreover, lower temporal frequency components (⩽0.4 GHz) demonstrated greater sensitivity to small changes in disease activity than previously published spatial features extracted from the same images.Significance.Spatiotemporal components of TD-DOI images may be more sensitive to small changes in RA disease activity than previously reported DOI features. TD-DOI may enable earlier detection of RA treatment failure, which would reduce the time needed to identify treatment failure and improve patient prognosis.


Asunto(s)
Artritis Reumatoide , Imagen Óptica , Fantasmas de Imagen , Artritis Reumatoide/diagnóstico por imagen , Imagen Óptica/métodos , Humanos , Factores de Tiempo , Simulación por Computador , Procesamiento de Imagen Asistido por Computador/métodos , Método de Montecarlo
2.
Phys Med Biol ; 69(12)2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38830365

RESUMEN

Objective.Effective treatment within 3-5 months of disease onset significantly improves rheumatoid arthritis (RA) prognosis. Nevertheless, 30% of RA patients fail their first treatment, and it takes 3-6 months to identify failure with current monitoring techniques. Time-domain diffuse optical imaging (TD-DOI) may be more sensitive to RA disease activity and could be used to detect treatment failure. In this report, we present the development of a TD-DOI hand imaging system and validate its ability to measure simulated changes in RA disease activity using tissue-mimicking finger phantoms.Approach.A TD-DOI system was built, based on a single-pixel camera architecture, and used to image solid phantoms which mimicked a proximal interphalangeal finger joint. For reference,in silicoimages of virtual models of the solid phantoms were also generated using Monte Carlo simulations. Spatiotemporal Fourier components were extracted from both simulated and experimental images, and their ability to distinguish between phantoms representing different RA disease activity was quantified.Main results.Many spatiotemporal Fourier components extracted from TD-DOI images could clearly distinguish between phantoms representing different states of RA disease activity.Significance.A TD-DOI system was built and validated using finger-mimicking solid phantoms. The findings suggest that the system could be used to monitor RA disease activity. This single-pixel TD-DOI system could be used to acquire longitudinal measures of RA disease activity to detect early treatment failure.


Asunto(s)
Artritis Reumatoide , Dedos , Imagen Óptica , Fantasmas de Imagen , Artritis Reumatoide/diagnóstico por imagen , Imagen Óptica/instrumentación , Imagen Óptica/métodos , Dedos/diagnóstico por imagen , Humanos , Factores de Tiempo
3.
J Chem Phys ; 159(19)2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-37987519

RESUMEN

Pheophytin a and chlorophyll a have been investigated by electrospray mass spectrometry in the positive and negative modes, in view of the importance of the knowledge of their properties in photosynthesis. Pheophytin and chlorophyll are both observed intensely in the protonated mode, and their main fragmentation route is the loss of their phytyl chain. Pheophytin is observed intact in the negative mode, while under collisions, it is primarily cleaved beyond the phytyl chain and loses the attaching propionate group. Chlorophyll is not detected in normal conditions in the negative mode, but addition of methanol solvent molecule is detected. Fragmentation of this adduct primarily forms a product (-30 amu) that dissociates into dephytyllated deprotonated chlorophyll. Semi-empirical molecular dynamics calculations show that the phytyl chain is unfolded from the chlorin cycle in pheophytin a and folded in chlorophyll a. Density functional theory calculations have been conducted to locate the charges on protonated and deprotonated pheophytin a and chlorophyll a and have found the major location sites that are notably more stable in energy by more than 0.5 eV than the others. The deprotonation site is found identical for pheophytin a and the chlorophyll a-methanol adduct. This is in line with experiment and calculation locating the addition of methanol on a double bond of deprotonated chlorophyll a.

4.
Oncogene ; 42(37): 2764-2775, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37573408

RESUMEN

Leukaemia is caused by the clonal evolution of a cell that accumulates mutations/genomic rearrangements, allowing unrestrained cell growth. However, recent identification of leukaemic mutations in the blood cells of healthy individuals revealed that additional events are required to expand the mutated clones for overt leukaemia. Here, we assessed the functional consequences of deleting the Fanconi anaemia A (Fanca) gene, which encodes a DNA damage response protein, in Spi1 transgenic mice that develop preleukaemic syndrome. FANCA loss increases SPI1-associated disease penetrance and leukaemic progression without increasing the global mutation load of leukaemic clones. However, a high frequency of leukaemic FANCA-depleted cells display heterozygous activating mutations in known oncogenes, such as Kit or Nras, also identified but at low frequency in FANCA-WT mice with preleukaemic syndrome, indicating that FANCA counteracts the emergence of oncogene mutated leukaemic cells. A unique transcriptional signature is associated with the leukaemic status of FANCA-depleted cells, leading to activation of MDM4, NOTCH and Wnt/ß-catenin pathways. We show that NOTCH signalling improves the proliferation capacity of FANCA-deficient leukaemic cells. Collectively, our observations indicate that loss of the FANC pathway, known to control genetic instability, fosters the expansion of leukaemic cells carrying oncogenic mutations rather than mutation formation. FANCA loss may contribute to this leukaemogenic progression by reprogramming transcriptomic landscape of the cells.


Asunto(s)
Proteína del Grupo de Complementación A de la Anemia de Fanconi , Leucemia , Animales , Ratones , Heterocigoto , Leucemia/genética , Mutación , Oncogenes/genética , Proteína del Grupo de Complementación A de la Anemia de Fanconi/genética
5.
Cancers (Basel) ; 16(1)2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38201462

RESUMEN

von Hippel-Lindau (VHL) disease, due to mutations of the tumor suppressor VHL gene, is a rare hereditary syndrome with a high risk of developing clear cell renal cell carcinoma (ccRCC). We asked whether the VHL-C162F mutation interferes with proliferation, migration, healing and forming colony ability by using wild-type VHL (WT VHL) and VHL-C162F reconstituted cells. We then analyzed the in vitro impact of the sunitinib treatment on VHL-C162F cells. We showed that VHL-C162F mutations have no impact on cell morphology, colony formation and migration ability but confer a significant higher healing ability than in WT VHL cells. RNA sequencing analysis revealed that VHL-C162F mutation upregulates genes involved in hypoxia and epithelial mesenchymal transition (EMT) pathways by comparison with VHL WT cells. We next showed a decrease in healing ability in VHL-C162F cells depleting on ZHX2, an oncogenic driver of ccRCC, highlighting the potential involvement of ZHX2 in aggressiveness of the VHL-C162F cells. Moreover, we found that sunitinib treatment inhibits ZHX2 expression and induces a reduced proliferation correlating with downregulation of P-ERK. Sunitinib treatment also conferred a more mesenchymal profile to VHL-C162F cells with significant downregulation of E-cadherin and upregulation of N-cadherin, Slug and AXL. Sunitinib therapy may therefore promote disease progression in VHL-C162F patients.

6.
Photoacoustics ; 28: 100404, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36185542

RESUMEN

Photoacoustic tomography (PAT) provides high resolution optical images of tissue at depths of up to several centimetres. This modality has been of interest to researchers for at least 30 years and is still the subject of intensive research. However, PAT researchers lack access to a comprehensive open-source graphical simulation and reconstruction software package. In this article, we introduce PATLAB, an open-source MATLAB-based graphical software package that can perform both PAT simulation and image reconstruction. PATLAB is simple to use yet is capable of complex PAT data processing tasks and offers advanced users a framework to build and test new methods.

7.
J Exp Med ; 219(8)2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35802137

RESUMEN

Ionizing radiations (IR) alter hematopoietic stem cell (HSC) function on the long term, but the mechanisms underlying these effects are still poorly understood. We recently showed that IR induces the derepression of L1Md, the mouse young subfamilies of LINE-1/L1 retroelements. L1 contributes to gene regulatory networks. However, how L1Md are derepressed and impact HSC gene expression are not known. Here, we show that IR triggers genome-wide H3K9me3 decrease that occurs mainly at L1Md. Loss of H3K9me3 at intronic L1Md harboring NF-κB binding sites motifs but not at promoters is associated with the repression of HSC-specific genes. This is correlated with reduced NFKB1 repressor expression. TNF-α treatment rescued all these effects and prevented IR-induced HSC loss of function in vivo. This TNF-α/NF-κB/H3K9me3/L1Md axis might be important to maintain HSCs while allowing expression of immune genes during myeloid regeneration or damage-induced bone marrow ablation.


Asunto(s)
Células Madre Hematopoyéticas , Histonas , Elementos de Nucleótido Esparcido Largo , FN-kappa B , Factor de Necrosis Tumoral alfa , Animales , Células Madre Hematopoyéticas/metabolismo , Histonas/metabolismo , Ratones , FN-kappa B/metabolismo , Radiación Ionizante , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo
8.
Nucleic Acids Res ; 50(14): 7938-7958, 2022 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-35871293

RESUMEN

Although originally described as transcriptional activator, SPI1/PU.1, a major player in haematopoiesis whose alterations are associated with haematological malignancies, has the ability to repress transcription. Here, we investigated the mechanisms underlying gene repression in the erythroid lineage, in which SPI1 exerts an oncogenic function by blocking differentiation. We show that SPI1 represses genes by binding active enhancers that are located in intergenic or gene body regions. HDAC1 acts as a cooperative mediator of SPI1-induced transcriptional repression by deacetylating SPI1-bound enhancers in a subset of genes, including those involved in erythroid differentiation. Enhancer deacetylation impacts on promoter acetylation, chromatin accessibility and RNA pol II occupancy. In addition to the activities of HDAC1, polycomb repressive complex 2 (PRC2) reinforces gene repression by depositing H3K27me3 at promoter sequences when SPI1 is located at enhancer sequences. Moreover, our study identified a synergistic relationship between PRC2 and HDAC1 complexes in mediating the transcriptional repression activity of SPI1, ultimately inducing synergistic adverse effects on leukaemic cell survival. Our results highlight the importance of the mechanism underlying transcriptional repression in leukemic cells, involving complex functional connections between SPI1 and the epigenetic regulators PRC2 and HDAC1.


Asunto(s)
Histona Desacetilasa 1 , Leucemia Eritroblástica Aguda , Complejo Represivo Polycomb 2 , Proteínas Proto-Oncogénicas , Transactivadores , Acetilación , Animales , Cromatina/genética , Histona Desacetilasa 1/genética , Leucemia Eritroblástica Aguda/genética , Ratones , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética
10.
Infect Dis Now ; 52(1): 44-46, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34634483

RESUMEN

BACKGROUND: Few studies have focused on the effects of COVID-19 on African populations. During the first epidemic wave in Senegal (May 1 to July 31, 2020), COVID-19 cases were isolated in treatment centers of epidemics (TCEs). We described the demographics and outcomes of COVID-19 cases in TCEs. PATIENTS AND METHODS: All cases with laboratory-confirmed COVID-19 in Thiès medical region of Senegal were included. RESULTS: COVID-19 was confirmed in 600 cases. Median age of cases (men: 357, 59.5%; women: 243, 40.5%) was 34.0years. The incidence was 12 per 100,000 inhabitants per month. Overall, 46 (7.7%) cases had a severe or critical form of the disease, and nine of them died. Of 455 cases quarantined in non-hospital TCEs, 340 (74.7%) had no symptom and 115 (25.3%) had mild or moderate symptoms. CONCLUSION: In this African retrospective cohort, COVID-19 cases were young and mostly asymptomatic with a low case fatality rate.


Asunto(s)
COVID-19 , Epidemias , Adulto , Femenino , Humanos , Incidencia , Laboratorios , Masculino , Estudios Retrospectivos , SARS-CoV-2 , Senegal/epidemiología
11.
Sci Rep ; 11(1): 16215, 2021 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-34376744

RESUMEN

Genetic diversity of surface exposed and stage specific Plasmodium falciparum immunogenic proteins pose a major roadblock to developing an effective malaria vaccine with broad and long-lasting immunity. We conducted a prospective genetic analysis of candidate antigens (msp1, ama1, rh5, eba175, glurp, celtos, csp, lsa3, Pfsea, trap, conserved chrom3, hyp9, hyp10, phistb, surfin8.2, and surfin14.1) for malaria vaccine development on 2375 P. falciparum sequences from 16 African countries. We described signatures of balancing selection inferred from positive values of Tajima's D for all antigens across all populations except for glurp. This could be as a result of immune selection on these antigens as positive Tajima's D values mapped to regions with putative immune epitopes. A less diverse phistb antigen was characterised with a transmembrane domain, glycophosphatidyl anchors between the N and C- terminals, and surface epitopes that could be targets of immune recognition. This study demonstrates the value of population genetic and immunoinformatic analysis for identifying and characterising new putative vaccine candidates towards improving strain transcending immunity, and vaccine efficacy across all endemic populations.


Asunto(s)
Variación Antigénica , Antígenos de Protozoos/inmunología , Simulación por Computador , Vacunas contra la Malaria/inmunología , Malaria Falciparum/inmunología , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , África/epidemiología , Antígenos de Protozoos/genética , Epítopos/inmunología , Humanos , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Plasmodium falciparum/genética , Estudios Prospectivos , Proteínas Protozoarias/genética
12.
Cancers (Basel) ; 13(15)2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34359798

RESUMEN

Von Hippel-Lindau disease (VHL) is a rare hereditary syndrome due to mutations of the VHL tumor suppressor gene. Patients harboring the R167Q mutation of the VHL gene have a high risk of developing ccRCCs. We asked whether the R167Q mutation with critical aspects of pseudo-hypoxia interferes with tumor plasticity. For this purpose, we used wild-type VHL (WT-VHL) and VHL-R167Q reconstituted cells. We showed that WT-VHL and VHL-R167Q expression had a similar effect on cell morphology and colony formation. However, cells transfected with VHL-R167Q display an intermediate, HIF2-dependent, epithelial-mesenchymal phenotype. Using RNA sequencing, we showed that this mutation upregulates the expression of genes involved in the hypoxia pathway, indicating that such mutation is conferring an enhanced pseudo-hypoxic state. Importantly, this hypoxic state correlates with the induction of genes belonging to epithelial-mesenchymal transition (EMT) and stemness pathways, as revealed by GSEA TCGA analysis. Moreover, among these deregulated genes, we identified nine genes specifically associated with a poor patient survival in the TCGA KIRC dataset. Together, these observations support the hypothesis that a discrete VHL point mutation interferes with tumor plasticity and may impact cell behavior by exacerbating phenotypic switching. A better understanding of the role of this mutation might guide the search for more effective treatments to combat ccRCCs.

14.
Sci Rep ; 11(1): 5227, 2021 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-33664349

RESUMEN

Mechanisms of tumor immune escape are quite diverse and require specific approaches for their exploration in syngeneic tumor models. In several human malignancies, galectin-9 (gal-9) is suspected to contribute to the immune escape. However, in contrast with what has been done for the infiltrating cells, the contribution of gal-9 produced by malignant cells has never been demonstrated in an animal model. Therefore, we derived isogenic clones-either positive or negative for gal-9-from the MB49 murine bladder carcinoma cell line. A progressive and consistent reduction of tumor growth was observed when gal-9-KO cells were subjected to serial transplantations into syngeneic mice. In contrast, tumor growth was unaffected during parallel serial transplantations into nude mice, thus linking tumor inhibition to the enhancement of the immune response against gal-9-KO tumors. This stronger immune response was at least in part explained by changing patterns of response to interferon-γ. One consistent change was a more abundant production of CXCL10, a major inflammatory factor whose production is often induced by interferon-γ. Overall, these observations demonstrate for the first time that serial transplantation into syngeneic mice can be a valuable experimental approach for the exploration of novel mechanisms of tumor immune escape.


Asunto(s)
Quimiocina CXCL10/genética , Galectinas/genética , Interferón gamma/genética , Escape del Tumor/genética , Neoplasias de la Vejiga Urinaria/genética , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Humanos , Interferón gamma/inmunología , Ratones , Ratones Desnudos , Trasplante Isogénico , Escape del Tumor/inmunología , Neoplasias de la Vejiga Urinaria/inmunología , Neoplasias de la Vejiga Urinaria/patología
15.
Med Trop Sante Int ; 1(1)2021 03 31.
Artículo en Francés | MEDLINE | ID: mdl-35685392

RESUMEN

The COVID-19 pandemic has an impact on health systems, whose modes of adaptation and response on the ground are still poorly documented and are evolving. The Dakar Integrated Support Center for Addictions (CEPIAD) has been implementing risk reduction since 2014, particularly with drug users. The COVID-19 pandemic and related public health measures were an obstacle to its attendance by patients, in particular due to movement restriction. In addition to the implementation of individual and collective preventive measures in the center, CEPIAD has experimented "take-home" for methadon that is generally provided daily through directly observed treatment. The center has also taken care of amnestied incarcerated cannabis users. Several aspects of this experience, perceived positively, could be relevant outside the pandemic context.


Asunto(s)
COVID-19 , COVID-19/epidemiología , Continuidad de la Atención al Paciente , Humanos , Metadona , Pandemias/prevención & control , Senegal
16.
Clin Cancer Res ; 26(13): 3307-3318, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32220889

RESUMEN

PURPOSE: Children with Down syndrome (constitutive trisomy 21) that develop acute lymphoblastic leukemia (DS-ALL) have a 3-fold increased likelihood of treatment-related mortality coupled with a higher cumulative incidence of relapse, compared with other children with B-cell acute lymphoblastic leukemia (B-ALL). This highlights the lack of suitable treatment for Down syndrome children with B-ALL. EXPERIMENTAL DESIGN: To facilitate the translation of new therapeutic agents into clinical trials, we built the first preclinical cohort of patient-derived xenograft (PDX) models of DS-ALL, comprehensively characterized at the genetic and transcriptomic levels, and have proven its suitability for preclinical studies by assessing the efficacy of drug combination between the MEK inhibitor trametinib and conventional chemotherapy agents. RESULTS: Whole-exome and RNA-sequencing experiments revealed a high incidence of somatic alterations leading to RAS/MAPK pathway activation in our cohort of DS-ALL, as well as in other pediatric B-ALL presenting somatic gain of the chromosome 21 (B-ALL+21). In murine and human B-cell precursors, activated KRASG12D functionally cooperates with trisomy 21 to deregulate transcriptional networks that promote increased proliferation and self renewal, as well as B-cell differentiation blockade. Moreover, we revealed that inhibition of RAS/MAPK pathway activation using the MEK1/2 inhibitor trametinib decreased leukemia burden in several PDX models of B-ALL+21, and enhanced survival of DS-ALL PDX in combination with conventional chemotherapy agents such as vincristine. CONCLUSIONS: Altogether, using novel and suitable PDX models, this study indicates that RAS/MAPK pathway inhibition represents a promising strategy to improve the outcome of Down syndrome children with B-cell precursor leukemia.


Asunto(s)
Síndrome de Down/complicaciones , Síndrome de Down/genética , Síndrome de Down/metabolismo , Leucemia de Células B/diagnóstico , Leucemia de Células B/etiología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Transducción de Señal , Proteínas ras/metabolismo , Animales , Biología Computacional/métodos , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Perfilación de la Expresión Génica , Humanos , Inmunofenotipificación , Leucemia de Células B/terapia , Ratones , Ratones Transgénicos , Oncogenes , Inhibidores de Proteínas Quinasas/farmacología , Piridonas/farmacología , Pirimidinonas/farmacología , Transducción de Señal/efectos de los fármacos
17.
Bull Soc Pathol Exot ; 112(3): 137-146, 2019.
Artículo en Francés | MEDLINE | ID: mdl-31825191

RESUMEN

Neuro-Behçet (NB) African studies are mainly North African, but Sub-Saharan Africa is not to be outdone. Our aim was to describe diagnostic and therapeutic features of NB in a Senegalese series collected in Dakar. This was a descriptive and retrospective study conducted at the Neurology department of Fann Teaching Hospital in Dakar, Senegal. All patients who met the NB's diagnostic criteria were included. Sixteen patients were collected, 14 males and 2 females with an average age of 40 years [18-71]. The main neurological signs were motor deficit (13 cases), headache (10 cases), and language disorders (4 cases). Extra-neurological signs were dermatological (14 cases), ocular (2 cases), and articular (2 cases) with aseptic unilateral gonarthritis. Fever was present in 9 patients. Neurological involvement was mostly isolated parenchymal (8 cases) or mixed (6 cases). The main clinical forms of NB were rhombencephalitis (8 cases) and retrobulbar optic neuritis (4 cases). Seven patients had a cerebral angio-Behçet with cerebral venous thrombosis (3 cases), ischemic stroke (2 cases), and intracerebral hematoma (2 cases). Under prednisone (16 cases) and azathioprine (3 cases), the short-term clinical outcome was mostly favorable (14 cases) with a modified Rankin scale at 2. NB is an under-diagnosed adult male disease in Sub-Saharan Africa and further studies are needed.


Les études africaines sur le neuro-Behçet (NB) sont majoritairement maghrébines, mais l'Afrique noire n'est pas en reste. L'objectif de l'étude était de décrire les particularités diagnostiques et thérapeutiques du NB dans une série sénégalaise colligée à Dakar. Il s'agit d'une étude rétrospective à visée descriptive menée à la clinique de neurologie du centre hospitalier universitaire de Fann de Dakar, au Sénégal. Tous les patients répondant aux critères diagnostiques de NB ont été inclus. Seize patients ont été colligés, 14 hommes et deux femmes avec un âge moyen de 40 ans [18­71]. Les principaux signes neurologiques étaient un déficit moteur (13 cas), des céphalées (10 cas) et un trouble du langage (4 cas). Les signes extraneurologiques étaient dermatologiques (14 cas), oculaires (2 cas) et articulaires (2 cas) à type de gonarthrite unilatérale aseptique. Une fièvre était présente chez neuf patients. L'atteinte neurologique était majoritairement parenchymateuse isolée (8 cas) ou mixte (6 cas). Les principales formes cliniques de NB étaient la rhombencéphalite (8 cas) et la névrite optique rétrobulbaire (4 cas). Sept patients avaient un angio-Behçet cérébral à type de thromboses veineuses cérébrales (3 cas), d'infarctus cérébraux (2 cas) et d'hématomes intracérébraux (2 cas). Sous prednisone (16 cas) et azathioprine (3 cas), l'évolution clinique à court terme était majoritairement favorable (14 cas) avec un score de Rankin modifié de 2 au moment de l'exeat. Le NB est une maladie de l'homme adulte sous-diagnostiquée en Afrique noire. Des études ultérieures multicentriques nationales et sous-régionales sont souhaitables.


Asunto(s)
Síndrome de Behçet/complicaciones , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/terapia , Trombosis Intracraneal/diagnóstico , Trombosis Intracraneal/etiología , Trombosis Intracraneal/terapia , Adolescente , Adulto , África del Sur del Sahara/epidemiología , Anciano , Síndrome de Behçet/epidemiología , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/etiología , Hemorragia Cerebral/terapia , Estudios de Cohortes , Femenino , Hospitales de Enseñanza , Humanos , Trombosis Intracraneal/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Senegal/epidemiología , Adulto Joven
18.
Cancer Discov ; 9(12): 1736-1753, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31662298

RESUMEN

Fusion oncogenes are prevalent in several pediatric cancers, yet little is known about the specific associations between age and phenotype. We observed that fusion oncogenes, such as ETO2-GLIS2, are associated with acute megakaryoblastic or other myeloid leukemia subtypes in an age-dependent manner. Analysis of a novel inducible transgenic mouse model showed that ETO2-GLIS2 expression in fetal hematopoietic stem cells induced rapid megakaryoblastic leukemia whereas expression in adult bone marrow hematopoietic stem cells resulted in a shift toward myeloid transformation with a strikingly delayed in vivo leukemogenic potential. Chromatin accessibility and single-cell transcriptome analyses indicate ontogeny-dependent intrinsic and ETO2-GLIS2-induced differences in the activities of key transcription factors, including ERG, SPI1, GATA1, and CEBPA. Importantly, switching off the fusion oncogene restored terminal differentiation of the leukemic blasts. Together, these data show that aggressiveness and phenotypes in pediatric acute myeloid leukemia result from an ontogeny-related differential susceptibility to transformation by fusion oncogenes. SIGNIFICANCE: This work demonstrates that the clinical phenotype of pediatric acute myeloid leukemia is determined by ontogeny-dependent susceptibility for transformation by oncogenic fusion genes. The phenotype is maintained by potentially reversible alteration of key transcription factors, indicating that targeting of the fusions may overcome the differentiation blockage and revert the leukemic state.See related commentary by Cruz Hernandez and Vyas, p. 1653.This article is highlighted in the In This Issue feature, p. 1631.


Asunto(s)
Leucemia Mieloide Aguda/patología , Proteínas de Fusión Oncogénica/genética , Adolescente , Factores de Edad , Animales , Niño , Preescolar , Femenino , Humanos , Lactante , Leucemia Mieloide Aguda/genética , Ratones , Trasplante de Neoplasias , Factores de Transcripción , Células Tumorales Cultivadas
19.
Blood ; 134(21): 1821-1831, 2019 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-31527074

RESUMEN

B-cell prolymphocytic leukemia (B-PLL) is a rare hematological disorder whose underlying oncogenic mechanisms are poorly understood. Our cytogenetic and molecular assessments of 34 patients with B-PLL revealed several disease-specific features and potential therapeutic targets. The karyotype was complex (≥3 abnormalities) in 73% of the patients and highly complex (≥5 abnormalities) in 45%. The most frequent chromosomal aberrations were translocations involving MYC [t(MYC)] (62%), deletion (del)17p (38%), trisomy (tri)18 (30%), del13q (29%), tri3 (24%), tri12 (24%), and del8p (23%). Twenty-six (76%) of the 34 patients exhibited an MYC aberration, resulting from mutually exclusive translocations or gains. Whole-exome sequencing revealed frequent mutations in TP53, MYD88, BCOR, MYC, SF3B1, SETD2, CHD2, CXCR4, and BCLAF1. The majority of B-PLL used the IGHV3 or IGHV4 subgroups (89%) and displayed significantly mutated IGHV genes (79%). We identified 3 distinct cytogenetic risk groups: low risk (no MYC aberration), intermediate risk (MYC aberration but no del17p), and high risk (MYC aberration and del17p) (P = .0006). In vitro drug response profiling revealed that the combination of a B-cell receptor or BCL2 inhibitor with OTX015 (a bromodomain and extra-terminal motif inhibitor targeting MYC) was associated with significantly lower viability of B-PLL cells harboring a t(MYC). We concluded that cytogenetic analysis is a useful diagnostic and prognostic tool in B-PLL. Targeting MYC may be a useful treatment option in this disease.


Asunto(s)
Leucemia Prolinfocítica Tipo Células B/genética , Proteínas Proto-Oncogénicas c-myc/genética , Proteína p53 Supresora de Tumor/genética , Anciano , Anciano de 80 o más Años , Aberraciones Cromosómicas , Análisis Citogenético , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico
20.
Nat Commun ; 10(1): 1935, 2019 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-31028249

RESUMEN

Despite their location at the cell surface, several receptor tyrosine kinases (RTK) are also found in the nucleus, as either intracellular domains or full length proteins. However, their potential nuclear functions remain poorly understood. Here we find that a fraction of full length Colony Stimulating Factor-1 Receptor (CSF-1R), an RTK involved in monocyte/macrophage generation, migrates to the nucleus upon CSF-1 stimulation in human primary monocytes. Chromatin-immunoprecipitation identifies the preferential recruitment of CSF-1R to intergenic regions, where it co-localizes with H3K4me1 and interacts with the transcription factor EGR1. When monocytes are differentiated into macrophages with CSF-1, CSF-1R is redirected to transcription starting sites, colocalizes with H3K4me3, and interacts with ELK and YY1 transcription factors. CSF-1R expression and chromatin recruitment is modulated by small molecule CSF-1R inhibitors and altered in monocytes from chronic myelomonocytic leukemia patients. Unraveling this dynamic non-canonical CSF-1R function suggests new avenues to explore the poorly understood functions of this receptor and its ligands.


Asunto(s)
Regulación de la Expresión Génica , Leucemia Mielomonocítica Crónica/genética , Factor Estimulante de Colonias de Macrófagos/farmacología , Macrófagos/efectos de los fármacos , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Sistemas CRISPR-Cas , Membrana Celular/química , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Cromatina/química , Cromatina/efectos de los fármacos , Cromatina/metabolismo , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Colorantes Fluorescentes/química , Edición Génica , Células HEK293 , Histonas/genética , Histonas/metabolismo , Humanos , Leucemia Mielomonocítica Crónica/metabolismo , Leucemia Mielomonocítica Crónica/patología , Factor Estimulante de Colonias de Macrófagos/metabolismo , Macrófagos/citología , Macrófagos/metabolismo , Maleimidas/química , Cultivo Primario de Células , Unión Proteica , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/antagonistas & inhibidores , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Transducción de Señal , Células THP-1 , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/metabolismo , Proteína Elk-1 con Dominio ets/genética , Proteína Elk-1 con Dominio ets/metabolismo
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