27 research outputs found
Enhancer Reprogramming Confers Dependence on Glycolysis and IGF Signaling in KMT2D Mutant Melanoma.
Histone methyltransferase KMT2D harbors frequent loss-of-function somatic point mutations in several tumor types, including melanoma. Here, we identify KMT2D as a potent tumor suppressor in melanoma through an in vivo epigenome-focused pooled RNAi screen and confirm the finding by using a genetically engineered mouse model (GEMM) based on conditional and melanocyte-specific deletion of KMT2D. KMT2D-deficient tumors show substantial reprogramming of key metabolic pathways, including glycolysis. KMT2D deficiency aberrantly upregulates glycolysis enzymes, intermediate metabolites, and glucose consumption rates. Mechanistically, KMT2D loss causes genome-wide reduction of H3K4me1-marked active enhancer chromatin states. Enhancer loss and subsequent repression of IGFBP5 activates IGF1R-AKT to increase glycolysis in KMT2D-deficient cells. Pharmacological inhibition of glycolysis and insulin growth factor (IGF) signaling reduce proliferation and tumorigenesis preferentially in KMT2D-deficient cells. We conclude that KMT2D loss promotes tumorigenesis by facilitating an increased use of the glycolysis pathway for enhanced biomass needs via enhancer reprogramming, thus presenting an opportunity for therapeutic intervention through glycolysis or IGF pathway inhibitors
Monocytes induce STAT3 activation in human mesenchymal stem cells to promote osteoblast formation
A major therapeutic challenge is how to replace bone once it is lost. Bone loss is a characteristic of chronic inflammatory and degenerative diseases such as rheumatoid arthritis and osteoporosis. Cells and cytokines of the immune system are known to regulate bone turnover by controlling the differentiation and activity of osteoclasts, the bone resorbing cells. However, less is known about the regulation of osteoblasts (OB), the bone forming cells. This study aimed to investigate whether immune cells also regulate OB differentiation. Using in vitro cell cultures of human bone marrow-derived mesenchymal stem cells (MSC), it was shown that monocytes/macrophages potently induced MSC differentiation into OBs. This was evident by increased alkaline phosphatase (ALP) after 7 days and the formation of mineralised bone nodules at 21 days. This monocyte-induced osteogenic effect was mediated by cell contact with MSCs leading to the production of soluble factor(s) by the monocytes. As a consequence of these interactions we observed a rapid activation of STAT3 in the MSCs. Gene profiling of STAT3 constitutively active (STAT3C) infected MSCs using Illumina whole human genome arrays showed that Runx2 and ALP were up-regulated whilst DKK1 was down-regulated in response to STAT3 signalling. STAT3C also led to the up-regulation of the oncostatin M (OSM) and LIF receptors. In the co-cultures, OSM that was produced by monocytes activated STAT3 in MSCs, and neutralising antibodies to OSM reduced ALP by 50%. These data indicate that OSM, in conjunction with other mediators, can drive MSC differentiation into OB. This study establishes a role for monocyte/macrophages as critical regulators of osteogenic differentiation via OSM production and the induction of STAT3 signalling in MSCs. Inducing the local activation of STAT3 in bone cells may be a valuable tool to increase bone formation in osteoporosis and arthritis, and in localised bone remodelling during fracture repair
Regulating E-Cigarettes: Why Policies Diverge
This paper, part of a festschrift in honor of Professor Malcolm Feeley, explores the landscape of e-cigarette policy globally by looking at three jurisdictions that have taken starkly different approaches to regulating e-cigarettesβthe US, Japan, and China. Each of those countries has a robust tobacco industry, government agencies entrusted with protecting public health, an active and sophisticated scientific and medical community, and a regulatory structure for managing new pharmaceutical, tobacco, and consumer products. All three are signatories of the World Health Organizationβs Framework Convention on Tobacco Control, all are signatories of the Agreement on Trade-Related Aspects of Intellectual Property Rights, and all are members of the World Trade Organization. Which legal, economic, social and political differences between the three countries explain their diverse approaches to regulating e-cigarettes? Why have they embraced such dramatically different postures toward e-cigarettes? In seeking to answer those questions, the paper builds on Feeley\u27s legacy of comparative scholarship, policy analysis, and focus on law in action
Comparison Between Thromboelastography and Conventional Coagulation Test: Should We Abandon Conventional Coagulation Tests in Polytrauma Patients?
INTRODUCTION: TEG provides an in-vivo assessment of viscoelastic clot strength in whole blood compared with CCT, which may not reflect the influence of platelets. The aim of this study was to compare TEG vs. CCT in trauma patients stratified by mechanism of injury (MOI) and pre-existing coagulation status. METHODS: A retrospective, observational study of 230 polytrauma patients admitted to a University Hospital Level 1 Trauma Center, with TEG and CCT on admission stratified by MOI: multiple trauma (MT), isolated traumatic brain injury (TBI) or MT+TBI. Statistical analysis included correlation between TEG and CCT in all groups and a subgroup analysis of anticoagulated patients. Data were analyzed with ANOVA, Spearman and lineal regression when appropriate. Statistical significance was accepted at P\u3c0.05. RESULTS: TEG was normal in 28.7%, hypercoagulable in 68.3%, hypocoagulable in 7%. There was no difference in TEG status among the groups. The coagulation status was not affected by age, ISS or shock. The CCT were abnormal in 63.6% of patients with normal TEG. Normal or hypercoagulable-TEG was found in 21/23 patients on Coumadin who had elevated INR and in 10/11 patients on NOAC. An analysis of the 23 patients on Coumadin stratified by INR showed a normal or hypercoagulable-TEG in 21/23 patients. Only 2 patients had a hypocoagulable-TEG. Mortality was 5.2% (58.3% severe TBI). CONCLUSIONS: TEG is more useful than CCT in polytrauma patients, including patients on anticoagulants. TBI could increase the incidence of hypercoagulability in trauma. CCT are not useful from the standpoint of treatment
Traumatic Injuries to the Pregnant Patient: A Critical Literature Review
INTRODUCTION: Trauma during pregnancy is the leading non-obstetrical cause of maternal death and a significant public health burden. This study reviews the most common causes of trauma during pregnancy, morbidity, and mortality, and the impact upon perinatal outcomes associated with trauma, providing a management approach to pregnant trauma patients. MATERIALS AND METHODS: A systematic review of the current literature from January 2006 to July 2016 was performed. RESULTS: Fifty-one articles were identified, including a total of 95,949 patients. Motor vehicle crash was the most frequent cause of blunt trauma, followed by falls, assault both domestic and interpersonal violence, and penetrating injuries (gunshot and stab wounds). CONCLUSIONS: Trauma in pregnant women is associated with high rates of adverse maternal and neonatal outcomes. Knowledge of the mechanism of injury is important to identify the potential injuries and the complexity of the management of these patients. As in all traumatic events, prevention is of paramount importance
Assessing the altimetric measurement from CYGNSS data
The Cyclone Global Navigation Satellite System (CYGNSS) mission was designed to study hurricane intensification by measuring wind speeds in tropical cyclones. However, the delay-Doppler maps (DDM) that are produced can be used to estimate the sea surface height (SSH) at the specular reflection point on the ocean surface. Proof-of-concept studies that DDMs are suitable to solve for SSH have been recently reported (Clarizia et al., 2016; Mashburn et al., 2018), based on data acquired by the demonstration satellite experiment Tech Demo Sat -1 (TDS-1) carrying a GNSS-R receiver similar to the ones onboard CYGNSS. Although the precision of each 1-sec averaged SSH is considerably lower than that of the existing satellite altimeters, by virtue of the dense coverage and frequent revisit time exhibited by the constellation of 8 microsats, the error may be smoothed down considerably by optimal interpolation (Li et al., 2016). Hence the CYGNSS dataset presents a potential opportunity to sample the tropical oceans, and investigate the sensitivity of the SSH measurements to mesoscale eddies