Radiogene Plasmamembran-Transporte in Tumorzellen

Transporte über die Plasmamembran durch Pumpen, Transporter und Ionenkanäle schaffen und nutzen chemische und elektrische Gradienten zur pH-Homöostase, Substratversorgung und Kataboliten-Entsorgung einer jeden Zelle. Zudem kontrollieren sie das Zellvolumen und sind deswegen übergeordnete Regulatoren von Zellproliferation, Zellmigration und Zelltod. Ionenkanäle erzeugen in erregbaren Zellen elektrische Signale. Sie steuern aber als integrale Module auch biochemische Signaltransduktionsketten, indem sie zum Beispiel in Proteinkomplexen mit Membranrezeptoren und „downstream“ Effektor-Proteinen physisch interagieren oder Ca2+-Signale und Ca2+-Effektorproteine regulieren. Tumorzellen zeichnen sich durch eine aberrante Expression von Ionenkanälen/Transportern aus, welche spezifische Funktionen in der Tumorbiologie ausüben, die sich häufig von ihren ursprünglichen Funktionen in nicht-transformierten Zellen unterschieden. Ein plakatives Beispiel dazu sind spannungsaktivierte Natrium-Kanäle, die in normalen erregbaren Zellen Aktionspotentiale aufbauen und in metastasierenden Karzinomzellen die Gewebeinvasion steuern. Ziel der vorliegenden Promotionsarbeit war, in Tumorzellen die Modulation von Ionenkanälen/Transportern in der Plasmamembran durch therapeutisch relevante Dosen von ionisierender Strahlung zu beschreiben. Hierzu wurden in Zelllinien unterschiedlicher humaner Tumorentitäten (chronische myeloische Leukämie (CML), T-Zell akute lymphatischer Leukämie (T-ALL), Lungen-Adenokarzinom, Kopf-Hals-Plattenepithelkarzinom und Glioblastom) nach Bestrahlung mit 0 Gy bzw. 2-10 Gy Photonen mit der Patch-Clamp-Methode elektrophysiologisch abgeleitet und in der Spannungsklemme Ganzzell- bzw. makroskopische Cell attached-Ströme sowie in der 0 pA-Stromklemme das Membranpotential gemessen. Dabei zeigte sich, dass innerhalb wenigen Stunden nach Bestrahlung Ca2+ -permeable nichtselektive Kationenkanäle (nicht näher definiert in CML-Zellen, TRPM2 in T-ALL-Zellen), K+-Kanäle (Kv3.4 und hERG1 in CML-Zellen, IKCa in T-ALL- und Glioblastomzellen, BKCa in Glioblastomzellen,) sowie Cl--Kanäle (Clc-3- ähnliche Kanäle in Glioblastomzellen) aktivieren. Die radiogene Indukton der Cl-Kanal-Aktivierung in den Glioblastomzellen benötigte die Aktivität der BKCa-Kanäle, wodurch die bereits bekannte Signaling-Funktion der BKCa-Kanäle bestätigt wurde. Die Membranpotential-Ableitungen in den Lungenadenokarzinom-Zellen zeigten eine strahleninduzierte transiente Hyperpolarisation, gefolgt von einer länger anhaltenden Depolarisation des Membranpotentials, die 3 h nach Bestrahlung maximal war. Wegnahme der extrazellulären Glukose revertierte die radiogene Depolarisation, der Glukose-Transport-Hemmer Phlorizin und der EGFR-Tyrosinkinase-Inhibitor Erlotinib hemmten sie. Dies lässt auf eine radiogene, EGFR-Tyrosinkinase vermittelte Aktivierung einer Phlorizin-sensitiven Na+-gekoppelten Glukose-Aufnahme über SGLT-Transporter schließen. Eine radiogene SGLT-Aktivierung wurde auch in den Kopf-Hals-Plattenepithelkarzinom-Zellen beobachtet. Begleitende Experimente des Labors Experimentelle Radioonkologie und der Sektion für Strahlenbiologie und Molekulare Umweltforschung, Klinik für Radioonkologie in Tübingen, demonstrierten, dass die radiogene Aktivierung der Ionenkanäle/Transporter zum klonogenen Überleben der Tumorzellen beitragen. Pharmakologische Hemmung oder Knockdown der Ionenkanäle/Transporter radiosensibilisiert die Tumorzellen und zeigt damit deren funktionelle Relevanz für die DNA-Schadensantwort. Als Mechanismen konnte dabei Ionenkanal-reguliertes radiogenes Ca2+-Signaling identifiziert werden, das in CML-, T-ALL- und Glioblastom-Zellen nachgeschaltet Isoformen von CaMKII aktiviert, wodurch über Inhibition von Cdc-25 und Cdc-2 der Zellzyklus in den bestrahlten Zellen an den Fortschritt der DNA-Reparatur angepasst wird. In den Glioblastomzellen trägt zudem die radiogene Aktivierung der BKCa- und Cl--Kanäle zur verstärkten Migration und Gehirninfiltration der Zellen bei, was möglicherweise auch zum Therapieversagen beitragen kann. Mithilfe erhöhter SGLT-Aktivität erhöhen bestrahlte Karzinomzellen ihre Glukoseaufnahme, um so den durch DNA-Reparatur erhöhten Energieverbrauch ausgleichen zu können

Web-based e-learning environment, Journal of Telecommunications and Information Technology, 2003, nr 4

Using a progressive information technologies for development of web-based courses and their administration brings a lot of practical and theoretical problems. We know web course problem is only small solution concerning construction of a large entire web-based e-learning environment. One of a practical problem is how to construct web-based electronic courses that have to meet international AICC standards. Implementation of such strict statements resulted in a lot of small or larger difficulties if we had used an elementary HTML editor. Using a special web course oriented editors can absolutely solve this problem. The second problem is construction of the web-based e-learning application that can administrate such web courses and takes into consideration AICC regulations. Development of such web applications is founded on the latest web technologies. This article introduces one approach to the modeling of the two most important components (web-based course, web-based application) of the web-based e-learning environment, convenient for Military Academy in Brno and Czech army. The article outlines the structure of web subject, e-learning environment and their implementation1. The LMS’s structure and its functionality, based on a snaps algebra, belong to important results of the article

POWER TRANSFORMER MONITORING AND AMR SYSTEM SUPPORT FOR COMBINED OPERATION OF DISTRIBUTED RES AND DEMAND SIDE MANAGEMENT

ABSTRAC

Targeting TRPM2 Channels Impairs Radiation-Induced Cell Cycle Arrest and Fosters Cell Death of T Cell Leukemia Cells in a Bcl-2-Dependent Manner

Messenger RNA data of lymphohematopoietic cancer lines suggest a correlation between expression of the cation channel TRPM2 and the antiapoptotic protein Bcl-2. The latter is overexpressed in various tumor entities and mediates therapy resistance. Here, we analyzed the crosstalk between Bcl-2 and TRPM2 channels in T cell leukemia cells during oxidative stress as conferred by ionizing radiation (IR). To this end, the effects of TRPM2 inhibition or knock-down on plasma membrane currents, Ca2+ signaling, mitochondrial superoxide anion formation, and cell cycle progression were compared between irradiated (0–10 Gy) Bcl-2-overexpressing and empty vector-transfected Jurkat cells. As a result, IR stimulated a TRPM2-mediated Ca2+-entry, which was higher in Bcl-2-overexpressing than in control cells and which contributed to IR-induced G2/M cell cycle arrest. TRPM2 inhibition induced a release from G2/M arrest resulting in cell death. Collectively, this data suggests a pivotal function of TRPM2 in the DNA damage response of T cell leukemia cells. Apoptosis-resistant Bcl-2-overexpressing cells even can afford higher TRPM2 activity without risking a hazardous Ca2+-overload-induced mitochondrial superoxide anion formation

Global phosphoproteome profiling reveals unanticipated networks responsive to cisplatin treatment of embryonic stem cells

Cellular responses to DNA-damaging agents involve the activation of various DNA damage signaling and transduction pathways. Using quantitative and high-resolution tandem mass spectrometry, we determined global changes in protein level and phosphorylation site profiles following treatment of SILAC (stable isotope labeling by amino acids in cell culture)-labeled murine embryonic stem cells with the anticancer drug cisplatin. Network and pathway analyses indicated that processes related to the DNA damage response and cytoskeleton organization were significantly affected. Although the ATM (ataxia telangiectasia mutated) and ATR (ATM and Rad3-related) consensus sequence (S/T-Q motif) was significantly overrepresented among hyperphosphorylated peptides, about half of the >2-fold-upregulated phosphorylation sites based on the consensus sequence were not direct substrates of ATM and ATR. Eleven protein kinases mainly belonging to the mitogen-activated protein kinase (MAPK) family were identified as being regulated in their kinase domain activation loop. The biological importance of three of these kinases (cyclin-dependent kinase 7 [CDK7], Plk1, and KPCD1) in the protection against cisplatin-induced cytotoxicity was demonstrated by small interfering RNA (siRNA)-mediated knockdown. Our results indicate that the cellular response to cisplatin involves a variety of kinases and phosphatases not only acting in the nucleus but also regulating cytoplasmic targets, resulting in extensive cytoskeletal rearrangements. Integration of transcriptomic and proteomic data revealed a poor correlation between changes in the relative levels of transcripts and their corresponding proteins, but a large overlap in affected pathways at the levels of mRNA, protein, and phosphoprotein. This study provides an integrated view of pathways activated by genotoxic stress and deciphers kinases that play a pivotal role in regulating cellular processes other than the DNA damage response

Analiza energetske efikasnosti sušenja semenskog kukuruza u Institutu za kukuruz “Zemun Polje“ u Zemunu

In this paper actual parameter analysis of corn seed energy eficiency drying process was performed in Maize research institute „Zemun polje“ in Zemun. Energy consumption data and performances of old – natural gas based system and new – corncob combustion based system were compared and analyzed. This paper deals with basic improvement measures, biomass usage and corncob usage validation in this type of industrial systems.U ovom radu je analizirana i ispitana energetska efikasnost sušenja semenskog kukuruza u doradnom centru Instituta za kukuruz “Zemun Polje“ u Zemunu. Podaci o radu starog sistema sušenja koji je kao energent koristio prirodni gas, analizirani su i upoređeni sa energetskim parametrima novog sistema, koji kao energent koristi usitnjeni oklasak dobijen u procesu krunjenja semenskog kukuruza. Rad se takođe bavi i razmatranjem ekoloških aspekata korišćenja oklaska kao goriva i tehnoekonomskom opravdanošću primene primene ovakvog sistema sušenja

Deciphering the RNA landscape by RNAome sequencing

Current RNA expression profiling methods rely on enrichment steps for specific RNA classes, thereby not detecting all RNA species in an unperturbed manner. We report strand-specific RNAome sequencing that determines expression of small and large RNAs from rRNA-depleted total RNA in a single sequence run. Since current analysis pipelines cannot reliably analyze small and large RNAs simultaneously, we developed TRAP, Total Rna Analysis Pipeline, a robust interface that is also compatible with existing RNA sequencing protocols. RNAome sequencing quantitatively preserved all RNA classes, allowing cross-class comparisons that facilitates the identification of relationships between different RNA classes. We demonstrate the strength of RNAome sequencing in mouse embryonic stem cells treated with cisplatin. MicroRNA and mRNA expression in RNAome sequencing significantly correlated between replicates and was in concordance with both existing RNA sequencing methods and gene expression arrays generated from the same samples. Moreover, RNAome sequencing also detected additional RNA classes such as enhancer RNAs, anti-sense RNAs, novel RNA species and numerous differentially expressed RNAs undetectable by other methods. At the level of complete RNA classes, RNAome sequencing also identified a specific global repression of the microRNA and microRNA isoform classes after cisplatin treatment whereas all other classes such as mRNAs were unchanged. These characteristics of RNAome sequencing will significantly improve expression analysis as well as studies on RNA biology not covered by existing methods

The withdrawal of cortical cancellous iliac crest grafts by windowing technique - A retrospective comparative examination

In den Jahren zwischen 1981 und 2003 wurden 223 Patienten in der Klinik und Poliklinik der Mund-Kiefer-Gesichtschirurgie an der Universität in Würzburg mit autologem Beckenkammtransplantat im Bereich des Unterkiefers versorgt. Die häufigste Ursache für eine partielle Mandibuloektomie war ein Karzinom (89,96%). Drei verschiedene Techniken wurden für die Gewinnung des Beckenkammtransplantates angewendet. Bei 52 Patienten wurde mit der Transplantatentnahme die Crista iliaca entfernt. Bei 63 Patienten wurde nach der Entnahme die Crista iliaca reponiert und bei 37 Patienten wurde die Fenstertechnik verwendet. 71 Patienten hatten keinen Eintrag über die verwendete Technik. Lediglich 21 Patienten hatten postoperative Beschwerden. Davon wurde bei 8 Patienten die Crista iliaca wieder reponiert, bei 6 Personen wurde die Fenstertechnik verwendet und bei vieren wurde die Crista iliaca mit entfernt.Between 1981 and 2003 223 patients got a mandible reconstruction with iliac crest graft at the University of Wuerzburg. The most common cause for mandible resection was a carcinoma (82,96%). Three different techniques were used for the extraction of iliac crest bone. In 52 patients the crista iliaca was removed during the extraction of the iliac crest bone. Among 63 patients the crista iliaca was set back after the withdrawal of the bone and in 37 patients they used the windowing technique. 71 patients didn’t have an entry about the used technique. Only 21 patients have had postoperative problems. In 8 patients the crista iliaca was set back after the withdrawal of the bone, in 6 they used the windowing technique and among 4 persons the crista iliaca was removed