44 research outputs found
Inhibitors of GLUT/SLC2A Enhance the Action of BCNU and Temozolomide against High-Grade Gliomas
Glucose transport across glioblastoma membranes plays a crucial role in maintaining the enhanced glycolysis typical of high-grade gliomas and glioblastoma. We tested the ability of two inhibitors of the glucose transporters GLUT/SLC2A superfamily, indinavir (IDV) and ritonavir (RTV), and of one inhibitor of the Na/glucose antiporter type 2 (SGLT2/SLC5A2) superfamily, phlorizin (PHZ), in decreasing glucose consumption and cell proliferation of human and murine glioblastoma cells. We found in vitro that RTV, active on at least three different GLUT/SLC2A transporters, was more effective than IDV, a specific inhibitor of GLUT4/SLC2A4, both in decreasing glucose consumption and lactate production and in inhibiting growth of U87MG and Hu197 human glioblastoma cell lines and primary cultures of human glioblastoma. PHZ was inactive on the same cells. Similar results were obtained when cells were grown in adherence or as 3D multicellular tumor spheroids. RTV treatment but not IDV treatment induced AMP-activated protein kinase (AMPKα) phosphorylation that paralleled the decrease in glycolytic activity and cell growth. IDV, but not RTV, induced an increase in GLUT1/SLC2A1 whose activity could compensate for the inhibition of GLUT4/SLC2A4 by IDV. RTV and IDV pass poorly the blood brain barrier and are unlikely to reach sufficient liquoral concentrations in vivo to inhibit glioblastoma growth as single agents. Isobologram analysis of the association of RTV or IDV and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) or 4-methyl-5-oxo-2,3,4,6,8-pentazabicyclo[4.3.0]nona-2,7,9-triene-9-carboxamide (TMZ) indicated synergy only with RTV on inhibition of glioblastoma cells. Finally, we tested in vivo the combination of RTV and BCNU on established GL261 tumors. This drug combination increased the overall survival and allowed a five-fold reduction in the dose of BCNU
Symmetry of the Fermi surface and evolution of the electronic structure across the paramagnetic-helimagnetic transition in MnSi/Si(111)
MnSi has been extensively studied for five decades, nonetheless detailed
information on the Fermi surface (FS) symmetry is still lacking. This missed
information prevented from a comprehensive understanding the nature of the
magnetic interaction in this material. Here, by performing angle-resolved
photoemission spectroscopy on high-quality MnSi films epitaxially grown on
Si(111), we unveil the FS symmetry and the evolution of the electronic
structure across the paramagnetic-helimagnetic transition at T 40 K,
along with the appearance of sharp quasiparticle emission below T. The
shape of the resulting FS is found to fulfill robust nesting effects. These
effects can be at the origin of strong magnetic fluctuations not accounted for
by state-of-art quasiparticle self-consistent GW approximation. From this
perspective, the unforeseen quasiparticle damping detected in the paramagnetic
phase and relaxing only below T, along with the persistence of the d-bands
splitting well above T, at odds with a simple Stoner model for itinerant
magnetism, open the search for exotic magnetic interactions favored by FS
nesting and affecting the quasiparticles lifetime
explorative study on the use of omalizumab in patients suffering from interstitial cystitis bladder pain syndrome
The aim of this study was to evaluate the efficacy of omalizumab in the treatment of Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS), evaluated by visual analogue score for pain and urgency- frequency, O'Leary-Sant IC symptom and problem index questionnaire, Pain Urgency Frequency questionnaire and Patient Global Assessment questionnaire. Four female patients with a diagnosis of IC/BPS were included in the study, with an age between 20 and 39 years. In the first patient the subjective final evaluation was of a marked improvement. The second patient had a moderate improvement of the subjective final evaluation. The third patient considered her overall clinical situation to have slightly improved after treatment. One 32-year-old patient, with multiple allergies, discontinued treatment after 3 months and could not complete the study due to side effects. Omalizumab was subcutaneously administered to patients with IC/PBS; it induced both a subjective and objective improvement of symptoms in 2 patients enrolled in the study
Parma consensus statement on metabolic disruptors
A multidisciplinary group of experts gathered in Parma Italy for a workshop hosted by the University of Parma, May 16–18, 2014 to address concerns about the potential relationship between environmental metabolic disrupting chemicals, obesity and related metabolic disorders. The objectives of the workshop were to: 1. Review findings related to the role of environmental chemicals, referred to as “metabolic disruptors”, in obesity and metabolic syndrome with special attention to recent discoveries from animal model and epidemiology studies; 2. Identify conclusions that could be drawn with confidence from existing animal and human data; 3. Develop predictions based on current data; and 4. Identify critical knowledge gaps and areas of uncertainty. The consensus statements
are intended to aid in expanding understanding of the role of metabolic disruptors in the obesity and metabolic disease epidemics, to move the field forward by assessing the current state of the science and to identify research needs on the role of environmental chemical exposures in these diseases. We propose broadening the definition of obesogens to that of metabolic disruptors, to encompass chemicals that play a role in altered susceptibility to obesity, diabetes and related metabolic disorders including metabolic syndrome
Genetic Inactivation of <i>Notch1</i> Synergizes with Loss of <i>Trp53</i> to Induce Tumor Formation in the Adult Mouse Forebrain
Simultaneous genetic inactivation of the key Notch signaling mediator RBP-Jk and p53 leads to the formation of forebrain tumors in mice, suggesting a tumor suppressor role of the Notch pathway in this context. However, the contribution of individual Notch receptors to the tumor-suppressive activity of Notch signaling in the brain remains elusive. Here, we show that simultaneous Notch1 and Notch2 deletion, similar to complete ablation of canonical Notch signaling by Rbpj inactivation, cooperates with Trp53 deletion to promote tumor growth in the adult forebrain. We also demonstrate that inactivation of Notch1 and Trp53 in cells with active Notch signaling is sufficient to induce brain tumor or hyperplasia formation. Analysis of tumor location suggests a multifocal origin and shows that ventral forebrain regions and olfactory bulbs are the most affected sites. Hence, Notch1 cooperates with p53 to repress malignant transformation in the adult mouse forebrain