199,218 research outputs found
Proto-oncogene c-jun expression is induced by AML1-ETO in a JNK dependent manner:possible role in the pathogenesis of acute myeloid leukemia
No full textOverexpression of proto-oncogene c-jun and constitutive activation of the Jun NH2-terminal kinase (JNK) signaling pathway have been implicated in the leukemic transformation process. However, c-jun expression has not been investigated in acute myeloid leukemia (AML) cells containing the most common chromosomal translocations. t(8;21) is one of the most common AML-associated translocation and results in the AML1-ETO fusion protein. Overexpression of AML1-ETO in NIH3T3 cells leads to increased phosphorylation of Ser63 in c-Jun, which is generally JNK dependent. The role of the JNK signaling pathway for the functional properties of AML1-ETO is, however, unknown.
In the present study we found high expression levels of c-jun mRNA in t(8;21), t(15;17) or inv(16) positive patient cells by microarray analysis. Within t(8;21) positive patient samples, there was a correlation between AML1-ETO and c-jun mRNA expression levels. In myeloid U937 cells, c-jun mRNA and c-Jun protein expression levels increased upon induction of AML1-ETO. AML1-ETO transactivated the human c-jun promoter through the proximal AP-1 site via activating the JNK signaling pathway. JNK targets c-Jun and ATF-2, which also bind to the proximal AP-1 site in U937 cells, were also phosphorylated upon AML1-ETO induction. Furthermore, AML1-ETO induction increased the DNA binding capacity of c-Jun and ATF-2 to the proximal AP-1 site of the c-jun promoter, which might result in their enhanced transactivation capacities.
Interference with JNK and c-Jun activation by using JIP-1 or a JNK inhibitor reduced the transactivation capacity of AML1-ETO on the c-jun promoter and the pro-apoptotic function of AML1-ETO in U937 cells. AML1-ETO seems to activate the JNK signaling pathway by inducing the expression of a cytoplasmic factor, possibly G-CSF, because supernatant of AML1-ETO expressing cells was sufficient to induce phosphorylation of JNK and c-Jun in wildtype U937 cells.
This data demonstrates a novel mechanism of how AML1-ETO might exert positive effects on target gene expression and identifies the proto-oncogene c-jun as a common target gene in AML patient cells.Überexpression des Proto-Onkogens c-jun und konstitutive Aktivierung des Jun NH2-terminalen Kinase (JNK)-Signaltransduktionsweges sind wichtig für die leukämische Transformation in der Chronischen Myeloischen Leukämie. Die Expression von c-jun bei Akuter Myeloischer Leukämie (AML) mit den häufigsten reziproken Translokationen ist jedoch unbekannt. Bei einer der häufigsten AML Translokation t(8;21) wurde in Fibroblastenzellen gezeigt, daß das AML1-ETO-Fusionsgen die Phosphorylierung des Serin 63 in c-Jun erhöht. Die Rolle des JNK-Signalweges, der c-Jun am Serin 63 phosphorylieren kann, für die Funktion von AML1-ETO wurde bisher jedoch nicht untersucht. Weiterhin kann aktiviertes c-Jun durch eine positive Rückkoppelungsschleife über den c-jun Promotor zur Erhöhung der c-Jun Expression führen.
In der vorliegenden Arbeit konnten wir zeigen, daß AML Patientenzellen mit den häufigen Translokationen: t(8;21), t(15;17) oder inv(16) mehr c-jun mRNA besitzen im Vergleich zu Knochenmarkszellen gesunder Probanden. Weiterhin fanden wir eine hohe Korrelation zwischen der AML1-ETO und der c-jun mRNA bei t(8;21) positiven Patientenzellen. Induktion von AML1-ETO in der myeloischen U937 Zellinie erhöhte sowohl c-jun mRNA als auch c-Jun Proteinexpression. Damit konnten wir zeigen, daß AML1-ETO die Erhöhung der c-jun Expression bewirkt. Wir untersuchten den molekularen Mechanismus in U937 Zellen mittels transienter Transfektionen und fanden, daß AML1-ETO den c-jun Promotor durch die proximale AP-1 Seite transaktiviert. Diese Transaktivierung erfolgte indirekt über Aktivierung des JNK-Signaltransduktionsweges durch AML1-ETO. AML1-ETO-Induktion führte auch zur Phosphorylierung der JNK-Zielproteine c-Jun und ATF-2. Diese konnten im Gelretardierungsassay an die proximale AP-1 Seite des c-jun Promotors binden und wurden durch AML1-ETO-Induktion in ihrer Bindungsfähigkeit verstärkt. Deshalb nehmen wir an, daß die Transaktivierungskapazität des c-jun Promotors durch AML1-ETO über die Aktivierung des JNK-Signalweges läuft
Drosophila hematopoietic cells as a model to study in vivo the activity of the human oncogene AML1-ETO
No full textL'hématopoïèse est un processus complexe et dynamique qui conduit à la formation ainsi qu'au remplacement continu et régulé des cellules sanguines. Au cours de ce processus, une série de facteurs de transcription contrôle l'apparition, l'engagement et la différentiation des cellules souches dans un lignage déterminé. En particulier, chez les vertébrés, le facteur RUNX1/AML1 (pour Acute Myeloid Leukemia 1) est requis pour l'émergence des cellules souches hématopoïétiques ainsi que pour la différentiation des lignées myéloïdes et lymphoïdes. Chez l'homme, différentes altérations génétiques affectant AML1 sont liées au développement de pathologies du système hématopoïétique. Notamment, la translocation chromosomique t(8;21), codant la protéine de fusion AML1-ETO, est associée à 10-15 % des cas de leucémies myéloïde aiguës. Il a été décrit que AML1-ETO agit essentiellement en interférant avec la fonction de AML1 au cours de la différentiation hématopoïétique. Cependant, le mode d'action de cet oncogène reste mal compris et peu de facteurs modulant son activité sont connus. Récemment, de nombreux travaux ont mis en évidence que divers aspects du développement des cellules hématopoïétiques sont conservés de la Drosophile aux vertébrés. Notamment, les facteurs de transcription des familles RUNX et GATA, acteurs clefs de l'hématopoïèse chez les vertébrés, contrôlent aussi le développement des cellules sanguines chez la Drosophile. Tirant profit d'une part de la conservation phylogénétique des circuits géniques régulant l'hématopoïèse chez l'homme et la Drosophile et d'autre part des puissants outils d'analyses génétiques disponibles chez la Drosophile, nous avons cherché à utiliser la Drosophile comme système modèle pour étudier le mécanisme d'action de l'oncogène humain AML1-ETO et identifier des modulateurs de son activité. Nos résultats montrent que AML1-ETO exerce dans des cellules sanguines de la Drosophile dont la différentiation dépend de l'expression d'un facteur RUNX (Lozenge, LZ), des effets similaires à ceux observés dans des cellules leucémiques humaines portant la translocation t(8;21), à savoir : un blocage de la différenciation des cellules hématopoïétiques exprimant LZ et une augmentation de leur nombre. Grâce à la réalisation d'un crible génétique in vivo par interférence à l'ARN, nous avons identifié calpainB comme requis pour que AML1-ETO induise ces effets. De plus, nous avons pu montrer que l'inhibition des calpaines provoque la dégradation de AML1-ETO et diminue le potentiel clonogénique de cellules leucémiques humaines exprimant cette chimère. Ces travaux montrent que la Drosophile peut être utilisée comme modèle alternatif pour mieux comprendre la fonction de AML1-ETO et identifier de nouveaux facteurs régulant son activité.Hematopoiesis is a complex and dynamic process that leads to the formation and continuous blood cells replenishment. During this process, a series of transcription factors controls the appearance, commitment and differentiation of stem cells into specific lineages. In particular, in vertebrates, the factor RUNX1/AML1 (for Acute Myeloid Leukemia 1) is required for the emergence of hematopoietic stem cells and for the differentiation of both myeloid and lymphoid lineages. In humans, several genetic alterations affecting AML1 are linked to the development of different hemopathies. Notably, the chromosomal translocation t (8; 21), encoding the fusion protein AML1-ETO, is associated with 10-15% of cases of acute myeloid leukemia. It has been described that AML1-ETO acts essentially by interfering with AML1 function during hematopoietic differentiation. However, the mode of action of this oncogene remains poorly understood and few factors modulating its activity are known. Recently, numerous studies have shown that several aspects of hematopoietic development are conserved from Drosophila to vertebrates. Notably, transcription factors of RUNX and GATA families, which are key players in vertebrate's hematopoiesis, also control the development of blood cells in Drosophila. Taking advantage of the phylogenetic conservation of genetic circuitry regulating hematopoiesis between humans and Drosophila and of the powerful genetic tools available in Drosophila, we assessed whether Drosophila can provide a suitable model system to study the mechanism of action of the human oncogene AML1-ETO and to identify modulators of its activity. Our results show that AML1-ETO exerts in Drosophila blood cells expressing a RUNX factor (Lozenge, LZ) similar effects to those observed in human leukemic cells carrying the t(8;21), namely a differentiation blockage and an increased proliferation. In addition, by performing a large scale in vivo screen based on RNA interference, we identified calpainB as required for AML1-ETO-induced blood cell disorders in Drosophila. In addition, we showed that calpains inhibition resulted in AML1-ETO degradation and reduced the clonogenic potential of human leukemic cells expressing intrinsically this chimera. Our results establish that Drosophila can be used as an alternative model to better understand AML1-ETO function and to identify new factors regulating its activity
Standardized Work Framework Applied to ETO Context
No full textCustomer satisfaction is one of the main factor leading to customer loyalty and therefore continuous business relationship [1]. Customer satisfaction is correlated to the perceived quality of service, that is meant both as freedom from deficiencies and as ability to meet customer needs [2]. This dualism indicates that customers choose their business partners not only for their ability to standardize the provided products and services guaranteeing stable quality standards, but also for their awareness and flexibility in implementing customized solutions. The aim of this paper is to investigate how standardization, accomplished with Standardized Work (SW), is applicable to low-volume-high-mix context as Engineering-to-Order (ETO) ones and which benefits, if any, could be achieved. The study is developed by defining an application framework from literature first to high-volume-low-mix context, and further developed and refined with empirical research to fit ETO context. Empirical research has been supported and applied to FPZ Group
Proteomics of Acute Myeloid Leukemia
No full textAcute Myeloid Leukemia (AML) is characterized by specific cytogenetic aberrations that are strong determinants of prognostic outcome and therapeutic response. Because the pathological outcome of AML patients with cytogentic abnormalities differs considerably we hypothesized that their proteome may also differ specifically in their expression pattern, protein interaction pathways and posttranslational modifications. We performed this study using 42 AML patients diagnosed for various cytogenetic abnormalities based on two-dimensional gel electrophoresis and MALDI TOF Tandem MS (MS/MS) analysis. We could identify significant differences in the proteome and posttranslational modifications of peptides, later confirmed by other methods, between cytogenetic groups. The interactome analysis based on computational bioinformatics reveals a major regulating networks, MAPK8 and MYC for complex aberrant karyotype, TP53 for t(8;21), TP53- MYC- PRKAC for 11q23, JUN and MYC for Inv(16). We could show in our validation and characterisation experiments that survivin is a novel target of t(8;21) leukemia and AML1-ETO directly regulates its expression to induce the differentiation block that could be overcome by silencing its expression. Further, we analysed 42 MS spectra representative of hnRNPH1, Calreticulin and hnRNPA2/B1 in a peak explorer which reveals a cytogenetic specific posttranslational modification of β-O-linked N-acetyl glucosamine (O-GlcNAc) of hnRNPH1 in AML patients with 11q23 translocation, an acetylation of calreticulin in t(8;21) translocation and methylation of hnRNPA2/B1 in patients with translocations of t(8;21) and inv(16). This report may lead to a new thinking about the AML pathogenesis as differences at PTM level could be used to distinguish different subtypes of AML besides for testing the therapeutic significance. Further, we characterised the biological role of survivin identified specifically from t(8;21) patients. We could show that AML1-ETO induces the expression of survivin both in a cell line model and in primary human hematopoietic precursors. AML1-ETO activates the basal transcription of the survivin promoter and binds to the only AML1 core enhancer binding sequence, TGTGGT, in survivin promotor. Repression of AML1-ETO mediated induction of survivin expression by a specific short hairpin RNA restores C/EBPα protein and its basal transcriptional activity on its own promotor. This restoration differentiates AML1-ETO positive leukemic cells to terminal granulocytic differentiation and growth arrest. These observations indicate that the antiapoptotic survivin protein, which holds a great therapeutic promise, is a critical mediator of AML1-ETO induced defective granulopoiesis. Thus, proving that AML1-ETO induces inhibition of granulocytic differentiation by activating survivin expressio
Lean maturity assessment in ETO scenario
No full textThe obligatory path towards a lean manufacturing organization requires assessment and monitoring. However, a lean assessment framework is not yet available for the engineer to order (ETO) scenario. This work explored ten lean ETO maturity principles—identified from the literature—that take insight from three formally defined sets (Toyota Way, lean construction, and lean product development principles). A practical assessment model was proposed based on the evaluation of ten lean ETO objective criteria (four with mathematical formulation) and was validated on a real industrial case. A problem‐solving tool, including a new lean tool, called the Problem Focus Matrix (PFM), was also presented; this tool was aimed toward development of an integrated framework that would include the organization mission, management, and continuous improvement
The Hematopoietic Transcription Factors RUNX1 and ERG Prevent AML1-ETO Oncogene Overexpression and Onset of the Apoptosis Program in t(8;21) AMLs
No full textContains fulltext :
163345.pdf (Publisher’s version ) (Open Access)The t(8;21) acute myeloid leukemia (AML)-associated oncoprotein AML1-ETO disrupts normal hematopoietic differentiation. Here, we have investigated its effects on the transcriptome and epigenome in t(8,21) patient cells. AML1-ETO binding was found at promoter regions of active genes with high levels of histone acetylation but also at distal elements characterized by low acetylation levels and binding of the hematopoietic transcription factors LYL1 and LMO2. In contrast, ERG, FLI1, TAL1, and RUNX1 bind at all AML1-ETO-occupied regulatory regions, including those of the AML1-ETO gene itself, suggesting their involvement in regulating AML1-ETO expression levels. While expression of AML1-ETO in myeloid differentiated induced pluripotent stem cells (iPSCs) induces leukemic characteristics, overexpression increases cell death. We find that expression of wild-type transcription factors RUNX1 and ERG in AML is required to prevent this oncogene overexpression. Together our results show that the interplay of the epigenome and transcription factors prevents apoptosis in t(8;21) AML cells
Design Optimization: Tools and Methods for ETO Products
No full textThe design of Engineer-To-Order products needs tools and methods for reducing time and cost during the phase of the quotation preparation. Modularization is one of the more applied design methods for ETO systems; however, it is necessary to integrate traditional tools with practices of design optimization to improve the development of a proposal. Even if commercial design tools for modeling specific types of engineering systems are available, the application of design optimization is still based on the use of tools not integrated with each level of the design phases. Moreover, these tools often require software customization. The integration of geometrical modeling, simulations, analysis, and optimization concerns the interaction between different tools. This paper describes an approach to support the Multi-Object Optimization related to the design of complex ETO systems with a focus on the oil & gas context. In this context, Genetic Algorithms and Constraint Satisfaction Problems are introduced as tools to support the design optimization of steel structures. The approach includes the employment of different and integrated tools throughout the design phases. This paper also shows a collection of tools to support the different levels for the design of different ETO products during the preparation of an offer related to proposal submission
AML1/ETO accelerates cell migration and impairs cell-to-cell adhesion and homing of hematopoietic stem/progenitor cells
No full textThe AML1/ETO fusion protein found in acute myeloid leukemias functions as a transcriptional regulator by recruiting co-repressor complexes to its DNA binding site. In order to extend the understanding of its role in preleukemia, we expressed AML1/ETO in a murine immortalized pluripotent hematopoietic stem/progenitor cell line, EML C1, and found that genes involved in functions such as cell-to-cell adhesion and cell motility were among the most significantly regulated as determined by RNA sequencing. In functional assays, AML1/ETO-expressing cells showed a decrease in adhesion to stromal cells, an increase of cell migration rate in vitro, and displayed an impairment in homing and engraftment in vivo upon transplantation into recipient mice. Our results suggest that AML1/ETO expression determines a more mobile and less adherent phenotype in preleukemic cells, therefore altering the interaction with the hematopoietic niche, potentially leading to the migration across the bone marrow barrier and to disease progression
Pontin is a critical regulator for AML1-ETO-induced leukemia.
No full textInternational audienceThe oncogenic fusion protein AML1-ETO, also known as RUNX1-RUNX1T1 is generated by the t(8;21)(q22;q22) translocation, one of the most frequent chromosomal rearrangements in acute myeloid leukemia (AML). Identifying the genes that cooperate with or are required for the oncogenic activity of this chimeric transcription factor remains a major challenge. Our previous studies showed that Drosophila provides a genuine model to study how AML1-ETO promotes leukemia. Here, using an in vivo RNA interference screen for suppressors of AML1-ETO activity, we identified pontin/RUVBL1 as a gene required for AML1-ETO-induced lethality and blood cell proliferation in Drosophila. We further show that PONTIN inhibition strongly impaired the growth of human t(8;21)(+) or AML1-ETO-expressing leukemic blood cells. Interestingly, AML1-ETO promoted the transcription of PONTIN. Moreover, transcriptome analysis in Kasumi-1 cells revealed a strong correlation between PONTIN and AML1-ETO gene signatures and demonstrated that PONTIN chiefly regulated the expression of genes implicated in cell cycle progression. Concordantly, PONTIN depletion inhibited leukemic self-renewal and caused cell cycle arrest. All together our data suggest that the upregulation of PONTIN by AML1-ETO participate in the oncogenic growth of t(8;21) cells
Enhancing irrigation water management based on ETo prediction using machine learning to mitigate climate change
No full textThis study addressed the increasing challenges of climate change by exploring the use of machine learning (ML) algorithms to predict the reference evapotranspiration (ETo). Accurate ETo prediction is crucial for optimizing irrigation water management. This research aimed to assess the reliability and accuracy of ML algorithms in predicting ETo values. Three ETo calculation methods were employed: Penman-Monteith (PM), Hargreaves (HA), and Blaney-Criddle (BC). The study analyzed ETo and other climate variables using the modified Mann-Kendall test (m-MK) and Theil Sen’s slope estimator methods to identify trends. Multiple ML algorithms, including Support Vector Regression (SVR), Random Forest (RF), XGboost, K-Nearest Neighbor (KNN), Decision Trees (DT), Linear Regression (LR), and Multiple Linear Regression (MLR) were utilized for ETo prediction. The ML algorithms exhibited excellent performance, with coefficients of determination (R2) values ranging from 0.97 to 0.99 for PM, 0.99 for HA, and from 0.91 to 0.92 for BC. The models demonstrated a high value of the Kling-Gupta efficiency (KGE) with low Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) values. Strong correlations between the predicted and calculated daily ETo were observed with R2 values of 0.99, 0.99, and 0.92 for PM, HA, and BC methods, respectively. In conclusion, this study affirmed the accuracy and reliability of ML algorithms to match that of standard ETo prediction equations
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