Die transkriptionelle und epigenetische Regulation des humanen L1CAM Gens im Endometriumkarzinom

Das Endometriumkarzinom (EK) ist in den Industrieländern die häufi gste diagnostizierte invasive Tumorerkrankung des weiblichen Urogenitaltrakts. Bei der Klassifi zierung wird zwischen dem meist mit einem positiven Verlauf assoziierten Typ-I EK und dem aggressiven Typ-II EK unterschieden. Ergebnisse der letzten Jahre zeigen, dass dem Zelladhäsionsmolekül L1CAM, welches von gesundem Endometrium nicht exprimiert wird, eine entscheidende Rolle in der Tumorprogression zukommt. L1CAM wird dabei hauptsächlich bei hochgradigen Typ-II EKs, die als seröse und klarzellige Adenokarzinome eingestuft werden, detektiert. Es konnte bereits gezeigt werden, dass die Überexpression des L1CAM-Gens die Motilität der Tumorzellen sowie das Tumorwachstums fördert. Dabei ist ein charakteristisches Merkmal, dass die L1CAM-Genexpression oft mit der invasiven Front eines Tumors assoziiert ist. Es wird beschrieben, dass Zellen in der invasiven Front eine Epitheliale-Mesenchymale-Transition (EMT) durchlaufen und anschließend in das umgebende Gewebe invadieren. Dieser Prozess wird durch die L1CAM-Überexpression unterstützt. Derzeit ist immer noch unklar, wie es zu dieser atypischen L1CAM-Expression an der invasiven Tumorfront kommt. Die zentrale Frage der vorliegenden Arbeit war daher, welchen Regulationsmechanismen das L1CAM-Gen im endometrialen Tumorgewebe unterliegt. Um dies zu klären, wurde die transkriptionelle Regulation von L1CAM auf unterschiedlichen Ebenen untersucht. Dabei konnte gezeigt werden, dass die TGF-β1 induzierte EMT in EK-Zellen zu einer Aktivierung von L1CAM führt die durch den EMT assoziierten Transkriptionsfaktor Slug vermittelt wird. Die durchgeführten DNA-Bindungsanalysen bestätigen eine direkte Interaktion des Transkriptionsfaktors Slug mit den zwei alternativen Promotoren des L1CAMGens. Des Weiteren sind Slug und L1CAM auf mRNA-Ebene in EK-Zelllinien positiv miteinander korreliert. Neben dem EMT-Aktivator Slug konnte mit dem Repressor REST ein weiterer Regulator von L1CAM identifi ziert werden. Der Einfl uss von REST auf die L1CAM-Expression war zuvor bereits in neuronalen Zellen beschrieben worden. Der direkte Mechanismus, über den REST in die L1CAM-Expression eingreift, bleibt zu klären. Über der Ebene der transkriptionellen Regulation hinaus, konnte gezeigt werden, dass auch der epigenetischen Regulation eine bedeutende Rolle in der Kontrolle der L1CAM-Expression zukommt. So konnte nachgewiesen werden, dass sowohl ein Einfl uss der Histon-Deacetylierung als auch der DNA-Methylierung bei der Suppression des L1CAM-Gens vorliegt. Dementsprechend führte die Behandlung von EK-Zelllinien mit Inhibitoren der Histon-Deacetylasen und/oder DNA-Methyltransferasen (DNMTs) zu einer Aktivierung des L1CAM-Gens. Darüber hinaus konnte mittels einer Methylierunganalyse nachgewiesen werden, dass in EK-Zelllinien der Grad der Promoter-Hypomethylierung mit der L1CAM-Expression korreliert. Entgegen der Erwartungen führte die Behandlung von L1CAM exprimierenden Zelllinien mit DNMTInhibitoren, zu einer drastischen Abnahme der L1CAM-Expression. Die nachfolgende Analysen dieses Effekts offenbarten eine Aktivierung von microRNAs, insbesondere der miR-34a, welche sehr wahrscheinlich zu der post-transkriptionellen Regulation von L1CAM beiträgt. Zusammenfassend belegen die Daten dieser Arbeit eine komplexe Kontrolle des L1CAM-Gens auf mehreren Ebenen. So greifen sowohl epigenetische als auch transkriptionelle und post-transkriptionelle Mechanismen in die Expression von L1CAM ein. Eine Deregulation dieser komplexen Repression kann so zu einer fokalen Aktivierung von L1CAM in hochgradigen EKs führen

Chemokine‐Capturing Wound Contact Layer Rescues Dermal Healing

Excessive inflammation often impedes the healing of chronic wounds. Scavenging of chemokines by multiarmed poly(ethylene glycol)-glycosaminoglycan (starPEG-GAG) hydrogels has recently been shown to support regeneration in a diabetic mouse chronic skin wound model. Herein, a textile-starPEG-GAG composite wound contact layer (WCL) capable of selectively sequestering pro-inflammatory chemokines is reported. Systematic variation of the local and integral charge densities of the starPEG-GAG hydrogel component allows for tailoring its affinity profile for biomolecular signals of the wound milieu. The composite WCL is subsequently tested in a large animal (porcine) model of human wound healing disorders. Dampening excessive inflammatory signals without affecting the levels of pro-regenerative growth factors, the starPEG-GAG hydrogel-based WCL treatment induced healing with increased granulation tissue formation, angiogenesis, and deposition of connective tissue (collagen fibers). Thus, this biomaterials technology expands the scope of a new anti-inflammatory therapy toward clinical use

Assessing heterogeneity in flow and transport processes at the groundwater-surface water interface and their role in the degradation of organic contaminants

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L1CAM expression in endometrial carcinomas is regulated by usage of two different promoter regions

<p>Abstract</p> <p>Background</p> <p>The L1 cell adhesion molecule (L1CAM) was originally identified as a neural adhesion molecule involved in axon guidance. In many human epithelial carcinomas L1CAM is overexpressed and thereby augments cell motility, invasion and metastasis formation. L1CAM positive carcinomas are associated with bad prognosis. Recent data point out that L1CAM is regulated in a fashion similar to epithelial-mesenchymal transition (EMT). Previous studies have implied the transcription factors Slug and/or β-catenin in <it>L1CAM </it>transcriptional regulation. However, the regulation of human L1CAM expression at the transcriptional level is not well understood.</p> <p>Results</p> <p>To better understand the molecular basis of <it>L1CAM </it>transcriptional regulation, we carried out a detailed characterization of the human <it>L1CAM </it>promoter. We identified two transcription start sites, the first in front of a non-translated exon 0 (promoter 1) and the other next to the first protein-coding exon 1 (promoter 2). Both sites could be verified in endometrial carcinoma (EC) cell lines and appear to be used in a cell-type specific manner. The two identified promoter regions showed activity in luciferase reporter assays. Chromatin-IP analyses confirmed the <it>in silico </it>predicted E-boxes, binding sites for transcription factors Snail and Slug, as well as Lef-1 sites, which are related to β-catenin-mediated transcriptional regulation, in both promoters. Overexpression of β-catenin exclusively augmented activity of promoter 1 whereas Slug enhanced promoter 1 and 2 activity suggesting that both promoters can be active. Overexpression of β-catenin or Slug could upregulate L1CAM expression in a cell-type specific manner.</p> <p>Conclusions</p> <p>Our results, for the first time, provide evidence that the L1CAM gene has two functionally active promoter sites that are used in a cell-type specific manner. Slug and β-catenin are involved <it>L1CAM </it>transcriptional regulation. Nevertheless, Slug rather than β-catenin levels are correlated with L1CAM expression in EC cell lines. Our findings suggest that the <it>L1CAM </it>transcriptional regulation is more complex than anticipated and this study provides the basis for a better understanding of L1CAM regulation in non-neuronal/tumor cells.</p

Recall Responses to Tetanus and Diphtheria Vaccination Are Frequently Insufficient in Elderly Persons

Demographic changes and a more active life-style in older age have contributed to an increasing public awareness of the need for lifelong vaccination. Currently many older persons have been vaccinated against selected pathogens during childhood but lack regular booster immunizations. The impact of regular vaccinations when started late in life was analyzed in an open, explorative trial by evaluating the immune response against tetanus and diphtheria in healthy older individuals. 252 persons aged above 60 years received a booster vaccination against tetanus, diphtheria, pertussis and polio and a subcohort (n=87) was recruited to receive a second booster vaccination against tetanus, diphtheria and pertussis 5 years later. The percentage of unprotected individuals at the time of enrollment differed substantially for tetanus (12%) and diphtheria (65%). Despite protective antibody concentrations 4 weeks after the first vaccination in almost all vaccinees, antibodies had again dropped below protective levels in 10% (tetanus) and 45% (diphtheria) of the cohort after 5 years. Protection was restored in almost all vaccinees after the second vaccination. No correlation between tetanus- and diphtheria-specific responses was observed, and antibody concentrations were not associated with age-related changes in the T cell repertoire, inflammatory parameters, or CMV-seropositivity suggesting that there was no general biological “non-responder type.” Post-vaccination antibody concentrations depended on pre-existing plasma cells and B cell memory as indicated by a strong positive relationship between post-vaccination antibodies and pre-vaccination antibodies as well as antibody-secreting cells. In contrast, antigen-specific T cell responses were not or only weakly associated with antibody concentrations. In conclusion, our findings demonstrate that single shot vaccinations against tetanus and/or diphtheria do not lead to long-lasting immunity in many elderly persons despite administration at relatively short intervals. Sufficient antigen-specific B cell memory B generated by adequate priming and consecutive booster vaccinations and/or exposure is a prerequisite for long-term protection. Trial Registration EU Clinical Trials Register (EU-CTR); EudraCT number 2009-011742-26; www.clinicaltrialsregister.eu/ctr-search/trial/2009-011742-26/A

Entwicklung und Validierung eines Inventars zur Employability nach dem dualen Studium

Die Potenziale eines dualen Studiums führen zur Annahme, dass Absolventen und Absolventinnen über eine hohe Employability verfügen und sie damit gute Chancen bei der Erhaltung und Aufrechterhaltung einer Beschäftigung nach dem Studium haben. Um diese Annahme zu überprüfen, wurde ein Inventar entwickelt und mit Studierenden der Dualen Hochschule Baden-Württemberg erprobt. Zur Analyse der Daten wurden Hauptkomponentenanalysen, konfirmatorische Faktorenanalysen und ein Mann-Whitney-U-Test eingesetzt. In zwei Studien wurde ein reliables und valides Instrument entwickelt. Die Ergebnisse werden vor dem Hintergrund ihrer Anwendung in der Praxis diskutiert

L1CAM protein expression is associated with poor prognosis in non-small cell lung cancer

Background: The L1 cell adhesion molecule (L1CAM) is potentially involved in epithelial-mesenchymal transition (EMT). EMT marker expression is of prognostic significance in non-small cell lung cancer (NSCLC). The relevance of L1CAM for NSCLC is unclear. We investigated the protein expression of L1CAM in a cohort of NSCLC patients. L1CAM protein expression was correlated with clinico-pathological parameters including survival and markers of epithelial-mesenchymal transition. Results: L1CAM protein expression was found in 25% of squamous cell carcinomas and 24% of adenocarcinomas and correlated with blood vessel invasion and metastasis (p < 0.05). L1CAM was an independent predictor of survival in a multivariate analysis including pT, pN, and pM category, and tumor differentiation grade. L1CAM expression positively correlated with vimentin, beta-catenin, and slug, but inversely with E-cadherin (all p-values < 0.05). E-cadherin expression was higher in the tumor center than in the tumor periphery, whereas L1CAM and vimentin were expressed at the tumor-stroma interface. In L1CAM-negative A549 cells the L1CAM expression was upregulated and matrigel invasion was increased after stimulation with TGF-beta1. In L1CAM-positive SK-LU-1 and SK-LC-LL cells matrigel invasion was decreased after L1CAM siRNA knockdown. Conclusions: A subset of NSCLCs with vessel tropism and increased metastasis aberrantly expresses L1CAM. L1CAM is a novel prognostic marker for NSCLCs that is upregulated by EMT induction and appears to be instrumental for enhanced cell invasion

Diffusion of Xenon and Nitrous Oxide into the Bowel

Background: Nitrous oxide diffuses easily from blood into air filled spaces. Xenon is also a relatively insoluble gas, like nitrous oxide. Therefore, the authors measured xenon diffusion into obstructed bowel segments during xenon anesthesia and compared this with nitrous oxide and nitrogen diffusion. Methods: Twenty-one pentobarbital-anesthetized pigs were randomly assigned to three groups to receive either xenon-oxygen, nitrous oxide-oxygen, or nitrogen-oxygen (75%-25%), respectively. In each animal, four bowel segments of 15-cm length were isolated. A pressure-measuring catheter was inserted into the lumen, and 30 ml of room air was injected into the segments. Anesthesia with the selected gas mixture was performed for 4 h. Pressure in the segments was measured continuously. The volume of gaseous bowel content was measured on completion of the study. Results: The median volume of bowel gas in animals breathing nitrous oxide was 88.0 ml as compared with 39.0 ml with xenon anesthesia and 21.5 ml in the nitrogen-oxygen group. After 4 h of anesthesia, the intraluminal pressures in the nitrous oxide group were found to be significantly greater than in the control group and in the xenon group. Conclusions: The amount of diffused gas was significantly lower during xenon anesthesia than with nitrous oxide anesthesia but greater than with controls. Blood solubility can therefore be regarded as an important factor influencing gas diffusion into air filled cavities