Drosophila hematopoietic cells as a model to study in vivo the activity of the human oncogene AML1-ETO

L'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

Green technologies and their application in Malaysian construction industry

Construction industry is very important to the global urbanization. At the same time, the construction industry itself has tremendous impact on the environment especially during the construction and operation stage.All economic sectors, including construction industry, currently face an inescapable challenge posed by the term of sustainable development.The construction industry also lags behind compared to other sectors in its response to the term of sustainable development. The construction activities can contribute in putting sustainable development into practice by enhancing and protecting the natural environment, minimising its impact on the consumption of energy and natural resources especially during the construction stage. The construction industry faces its most serious challenge over the next two to three decades in finding appropriate solutions to overcome many issues regarding the term of sustainable development.Nowadays, green technologies play a very important role to promotes a societal move toward sustainability.Green technologies are practical solutions to achieve economic development and human satisfaction in harmony with the environment.For the construction industry, the use of green technologies are also a crucial issues towards achieving sustainable construction.In Malaysia, Construction Industry Development Board has initialised the Green Technology programme since 1999 as an environmental development programme initiative with the establishment of Technical Committee of Good Environmental Practices. However, after more than 10 years, the level of application of these kind of technologies are still at the infancy level.This paper attempt to identify the current level of green technologies among the Malaysian construction practitioners which include the contractors, consultants and clients

Sustainability performance in Malaysian construction industry : A study on the local construction stakeholders

For this research, the concept of sustainability had been divided into two different perspectives which include the financial sustainability performance (economics aspect) and non financial sustainability performance (environment and social aspect). A survey method was employed due to the reason that it is the most appropriate research design to obtain personal and social facts, beliefs and attitude on a large scale. Since the data of analysis is done at the company level, the unit of analysis for this research is the construction stakeholder's organization. The result of this study shows that the performance of financial sustainability is better than non financial sustainability. This paper attempts to identify the current level of sustainable construction performance among the Malaysian construction stakeholders

Issues in adapting supply-chain management (SCM) in construction industry

Construction constitutes an important element in economic development. The economics of the industry primarily to reduce costs and time and thus improve revenues, therefore the component of inputs integration and flow of materials become major perquisite for the industry to remain competitive. Appropriately adoption of Supply-Chain Management (SCM) is a great opportunity for the industry to be more effective and efficient. However, obstacles for SCM in the industry are e.g. the poor level of logistical competence, the partly limited competition, the strong project focus as well as the attitudes and traditions in the construction industry.The industry can learn from the SCM principles and practices.To fulfill the theme of the conference, the discussion of this paper will look into the integration of the supply chain in order to boost efficiency and effectiveness across all supply chain in completing construction projects.Its conclude as SCM should be considered as essential method to the performance and competitiveness of the construction enterprise considering the variety of materials, products and components it requires on each project, the range of subcontracting companies it normally engages, and the variety of consultants it works with

An in vivo RNA interference screen identifies gene networks controlling Drosophila melanogaster blood cell homeostasis

<p>Abstract</p> <p>Background</p> <p>In metazoans, the hematopoietic system plays a key role both in normal development and in defense of the organism. In Drosophila, the cellular immune response involves three types of blood cells: plasmatocytes, crystal cells and lamellocytes. This last cell type is barely present in healthy larvae, but its production is strongly induced upon wasp parasitization or in mutant contexts affecting larval blood cell homeostasis. Notably, several zygotic mutations leading to melanotic mass (or "tumor") formation in larvae have been associated to the deregulated differentiation of lamellocytes. To gain further insights into the gene regulatory network and the mechanisms controlling larval blood cell homeostasis, we conducted a tissue-specific loss of function screen using hemocyte-specific Gal4 drivers and <it>UAS-dsRNA </it>transgenic lines.</p> <p>Results</p> <p>By targeting around 10% of the Drosophila genes, this <it>in vivo </it>RNA interference screen allowed us to recover 59 melanotic tumor suppressor genes. In line with previous studies, we show that melanotic tumor formation is associated with the precocious differentiation of stem-cell like blood progenitors in the larval hematopoietic organ (the lymph gland) and the spurious differentiation of lamellocytes. We also find that melanotic tumor formation can be elicited by defects either in the fat body, the embryo-derived hemocytes or the lymph gland. In addition, we provide a definitive confirmation that lymph gland is not the only source of lamellocytes as embryo-derived plasmatocytes can differentiate into lamellocytes either upon wasp infection or upon loss of function of the Friend of GATA cofactor U-shaped.</p> <p>Conclusions</p> <p>In this study, we identify 55 genes whose function had not been linked to blood cell development or function before in Drosophila. Moreover our analyses reveal an unanticipated plasticity of embryo-derived plasmatocytes, thereby shedding new light on blood cell lineage relationship, and pinpoint the Friend of GATA transcription cofactor U-shaped as a key regulator of the plasmatocyte to lamellocyte transformation.</p

Genetic, molecular and physiological basis of variation in Drosophila gut immunocompetence

Gut immunocompetence involves immune, stress and regenerative processes. To investigate the determinants underlying inter-individual variation in gut immunocompetence, we perform enteric infection of 140 Drosophila lines with the entomopathogenic bacterium Pseudomonas entomophila and observe extensive variation in survival. Using genome-wide association analysis, we identify several novel immune modulators. Transcriptional profiling further shows that the intestinal molecular state differs between resistant and susceptible lines, already before infection, with one transcriptional module involving genes linked to reactive oxygen species (ROS) metabolism contributing to this difference. This genetic and molecular variation is physiologically manifested in lower ROS activity, lower susceptibility to ROS-inducing agent, faster pathogen clearance and higher stem cell activity in resistant versus susceptible lines. This study provides novel insights into the determinants underlying population-level variability in gut immunocompetence, revealing how relatively minor, but systematic genetic and transcriptional variation can mediate overt physiological differences that determine enteric infection susceptibility

Supply chain management in the Malaysian construction industry

The construction industry plays an important role in establishing the required infrastructure for socioeconomic development while being a major contributor to ward overall economic growth.As the national economy grows, the construction industry needs to satisfy the expansion and changes in construction demand.To meet the challenges of global competition,the Malaysian construction industry will have to respond to changes in demands.Since the performance of the industry has great implication to the national economy, the construction industry should be promoted to a greater echelon.Therefore, Supply Chain Management (SCM) is a great opportunity for the construction industry primarily to reduce costs and time, thus improving industrial productivity.However, there are obstacles that include poor levels of logistical competence, partly limited competition, strong project focus as well as the attitudes and traditions surrounding the issue.In congruent with SCM principles and practices, the construction industry should consider integrating SCM into its portfolio to boost efficiency and effectiveness throughout the construction value chain. This research looks into the practice of SCM in the Malaysian construction industry.The motives behind this study were to identify dimens ions involved in SCM practices among three categories of construction players, namely contractors, developers, and suppliers. Besides that, this study also went deep into acknowledging the level of intensity of each practice in order to gain a thorough understanding on the related issues.Based on the study, SCM in general, is reasonably considered a common practice in the Malaysian construction industry.It was also found that the level of SCM adoption is good among the construction players.Conclusively, this research has been successful in meeting its objectives.Despite having good adoption level of SCM practices, SCM understanding is still considerably low in certain aspects.This leaves heavy responsibilities on the construction-related government agencies to further enhance the understanding of the construction players regarding SCM practices

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely