Ligand Bound β1 Integrins Inhibit Procaspase-8 for Mediating Cell Adhesion-Mediated Drug and Radiation Resistance in Human Leukemia Cells

BACKGROUND: Chemo- and radiotherapeutic responses of leukemia cells are modified by integrin-mediated adhesion to extracellular matrix. To further characterize the molecular mechanisms by which β1 integrins confer radiation and chemoresistance, HL60 human acute promyelocytic leukemia cells stably transfected with β1 integrin and A3 Jurkat T-lymphoma cells deficient for Fas-associated death domain protein or procaspase-8 were examined. METHODOLOGY/PRINCIPAL FINDINGS: Upon exposure to X-rays, Ara-C or FasL, suspension and adhesion (fibronectin (FN), laminin, collagen-1; 5–100 µg/cm(2) coating concentration) cultures were processed for measurement of apoptosis, mitochondrial transmembrane potential (MTP), caspase activation, and protein analysis. Overexpression of β1 integrins enhanced the cellular sensitivity to X-rays and Ara-C, which was counteracted by increasing concentrations of matrix proteins in association with reduced caspase-3 and -8 activation and MTP breakdown. Usage of stimulatory or inhibitory anti β1 integrin antibodies, pharmacological caspase or phosphatidylinositol-3 kinase (PI3K) inhibitors, coprecipitation experiments and siRNA-mediated β1 integrin silencing provided further data showing an interaction between FN-ligated β1 integrin and PI3K/Akt for inhibiting procaspase-8 cleavage. CONCLUSIONS/SIGNIFICANCE: The presented data suggest that the ligand status of β1 integrins is critical for their antiapoptotic effect in leukemia cells treated with Ara-C, FasL or ionizing radiation. The antiapoptotic actions involve formation of a β1 integrin/Akt complex, which signals to prevent procaspase-8-mediated induction of apoptosis in a PI3K-dependent manner. Antagonizing agents targeting β1 integrin and PI3K/Akt signaling in conjunction with conventional therapies might effectively reduce radiation- and drug-resistant tumor populations and treatment failure in hematological malignancies

The Small Molecule Inhibitor QLT0267 Radiosensitizes Squamous Cell Carcinoma Cells of the Head and Neck

BACKGROUND: The constant increase of cancer cell resistance to radio- and chemotherapy hampers improvement of patient survival and requires novel targeting approaches. Integrin-Linked Kinase (ILK) has been postulated as potent druggable cancer target. On the basis of our previous findings clearly showing that ILK transduces antisurvival signals in cells exposed to ionizing radiation, this study evaluated the impact of the small molecule inhibitor QLT0267, reported as putative ILK inhibitor, on the cellular radiation survival response of human head and neck squamous cell carcinoma cells (hHNSCC). METHODOLOGY/PRINCIPAL FINDINGS: Parental FaDu cells and FaDu cells stably transfected with a constitutively active ILK mutant (FaDu-IH) or empty vectors, UTSCC45 cells, ILK(floxed/floxed(fl/fl)) and ILK(-/-) mouse fibroblasts were used. Cells grew either two-dimensionally (2D) on or three-dimensionally (3D) in laminin-rich extracellular matrix. Cells were treated with QLT0267 alone or in combination with irradiation (X-rays, 0-6 Gy single dose). ILK knockdown was achieved by small interfering RNA transfection. ILK kinase activity, clonogenic survival, number of residual DNA double strand breaks (rDSB; gammaH2AX/53BP1 foci assay), cell cycle distribution, protein expression and phosphorylation (e.g. Akt, p44/42 mitogen-activated protein kinase (MAPK)) were measured. Data on ILK kinase activity and phosphorylation of Akt and p44/42 MAPK revealed a broad inhibitory spectrum of QLT0267 without specificity for ILK. QLT0267 significantly reduced basal cell survival and enhanced the radiosensitivity of FaDu and UTSCC45 cells in a time- and concentration-dependent manner. QLT0267 exerted differential, cell culture model-dependent effects with regard to radiogenic rDSB and accumulation of cells in the G2 cell cycle phase. Relative to corresponding controls, FaDu-IH and ILK(fl/fl) fibroblasts showed enhanced radiosensitivity, which failed to be antagonized by QLT0267. A knockdown of ILK revealed no change in clonogenic survival of the tested cell lines as compared to controls. CONCLUSIONS/SIGNIFICANCE: Our data clearly show that the small molecule inhibitor QLT0267 has potent cytotoxic and radiosensitizing capability in hHNSCC cells. However, QLT0267 is not specific for ILK. Further in vitro and in vivo studies are necessary to clarify the potential of QLT0267 as a targeted therapeutic in the clinic

Interdisciplinary Research Project TiP.De - Theatre in Dementia Health Care

The interdisciplinary research project TiP.De - Theatre in Dementia Health Care aims at identifying the effects of theatre pedagogy on quality of life of people with dementia in two German nursing homes. The mixed-methods intervention study measures cognitive impairment, quality of life in daily living and agitation in a pre-post-comparison, as well as emotional reactions during the theatre pedagogical interventions of the participants. The intervention is expected to have a positive impact on cognitive impairment, quality of life, agitation and relationship between the participants and the assisting nursing home staff. Further data analysis will show correlations between specific items. The results and the theatre pedagogy concept for people with dementia will be published, so that theatre pedagogues are able to implement the concept in other nursing homes. The nursing situation, communication and work experience of nurses, as well as quality of life of people with dementia are going to be positively affected

Interdisciplinary Research Project TiP.De - Theatre in Dementia Health Care

The interdisciplinary research project TiP.De - Theatre in Dementia Health Care aims at identifying the effects of theatre pedagogy on quality of life of people with dementia in two German nursing homes. The mixed-methods intervention study measures cognitive impairment, quality of life in daily living and agitation in a pre-post-comparison, as well as emotional reactions during the theatre pedagogical interventions of the participants. The intervention is expected to have a positive impact on cognitive impairment, quality of life, agitation and relationship between the participants and the assisting nursing home staff. Further data analysis will show correlations between specific items. The results and the theatre pedagogy concept for people with dementia will be published, so that theatre pedagogues are able to implement the concept in other nursing homes. The nursing situation, communication and work experience of nurses, as well as quality of life of people with dementia are going to be positively affected

Apps für Kindergartenkinder: Lernen oder Aufmerksamkeitsraub? – Anforderungen an Lernapps aus kognitionspsychologischer Perspektive

Der vorliegende Beitrag befasst sich mit der Frage, wie Lernapps für Kinder in der frühen Kindheit gestaltet werden müssen, um Lernprozesse zu ermöglichen. Dazu wird multimediales und digitales Lernen aus kognitionspsychologischer Sicht beleuchtet. Theoretische Modelle legen nahe, dass die Verarbeitung neuer Informationen im Arbeitsgedächtnis über zwei Kanäle erfolgt, einen akustischen und einen visuellen Kanal. Doch sind die Verarbeitungsressourcen des Arbeitsgedächtnisses begrenzt: Neben der Verarbeitung relevanter neuer Informationen und der Integration neuen und bereits gespeicherten Wissens werden Ressourcen - je nach Aufmerksamkeitslenkung - durch die Verarbeitung irrelevanter Reize oder durch die Inhibition dieser Reize gebunden. Diese und weitergehende theoretische Annahmen bestätigen sich in empirischen Studien zu multimedialem Lernen. Daraus lassen sich Hinweise ableiten, welche Anforderungen Lernapps erfüllen sollten, um den Lernprozess zu ermöglichen und zu unterstützen. So reduziert sich die Beanspruchung des Arbeitsgedächtnisses durch das Weglassen irrelevanter Informationen und gleichkanaliger Redundanzen sowie die Beschränkung auf nur wenige Wahlmöglichkeiten. Erleichtert wird das Lernen (komplexer Inhalte) zudem durch die Hervorhebung essentieller Informationen, Vorentlastung und die parallele Darbietung gleicher Informationen über beide Verarbeitungskanäle. Die Berücksichtigung und Verbreitung dieses kognitionspsychologischen Wissens im Bereich der (Medien-)Pädagogik wie auch der App-Entwicklung/ Informatik birgt die Chance, kindliche Lernprozesse durch die Entwicklung und den Einsatz adäquater digitaler Medien zu ermöglichen und optimal zu unterstützen.The present paper addresses the question how educational apps need to be constructed in order to support learning processes in early childhood. To this end multimedia and digital learning are examined from a cognitive science perspective. Theoretical frameworks suggest that information is processed via two channels in working memory, an auditory and a visual channel. But processing capacities are limited: Essential processing of new information and generative processing integrating new and previously stored knowledge are hampered by resources being deployed to non-essential processing of irrelevant information or the inhibition of such information - contingent to attention control. These and further theoretical assumptions are supported by empirical data. Research findings imply that educational apps should meet certain criteria in order to facilitate and support learning processes: Working memory load needs to be reduced by the omission of irrelevant information and same-channel redundancies as well as by limiting the number of available options. Learning (of complex content) is facilitated by emphasizing essential information, pre-presentation of crucial information and parallel presentation of the same content via both processing channels. Incorporating and spreading these insights from cognitive and learning sciences in the fields of education and app development/information technology has the potential to facilitate and support children’s learning processes

Apps für Kindergartenkinder: Lernen oder Aufmerksamkeitsraub? Anforderungen an Lernapps aus kognitionspsychologischer Perspektive

Der vorliegende Beitrag befasst sich mit der Frage, wie Lernapps für Kinder in der frühen Kindheit gestaltet werden müssen, um Lernprozesse zu ermöglichen. Dazu wird multimediales und digitales Lernen aus kognitionspsychologischer Sicht beleuchtet. Theoretische Modelle legen nahe, dass die Verarbeitung neuer Informationen im Arbeitsgedächtnis über zwei Kanäle erfolgt, einen akustischen und einen visuellen Kanal. Doch sind die Verarbeitungsressourcen des Arbeitsgedächtnisses begrenzt: Neben der Verarbeitung relevanter neuer Informationen und der Integration neuen und bereits gespeicherten Wissens werden Ressourcen - je nach Aufmerksamkeitslenkung - durch die Verarbeitung irrelevanter Reize oder durch die Inhibition dieser Reize gebunden. Diese und weitergehende theoretische Annahmen bestätigen sich in empirischen Studien zu multimedialem Lernen. Daraus lassen sich Hinweise ableiten, welche Anforderungen Lernapps erfüllen sollten, um den Lernprozess zu ermöglichen und zu unterstützen. So reduziert sich die Beanspruchung des Arbeitsgedächtnisses durch das Weglassen irrelevanter Informationen und gleichkanaliger Redundanzen sowie die Beschränkung auf nur wenige Wahlmöglichkeiten. Erleichtert wird das Lernen (komplexer Inhalte) zudem durch die Hervorhebung essentieller Informationen, Vorentlastung und die parallele Darbietung gleicher Informationen über beide Verarbeitungskanäle. Die Berücksichtigung und Verbreitung dieses kognitionspsychologischen Wissens im Bereich der (Medien-)Pädagogik wie auch der App-Entwicklung/ Informatik birgt die Chance, kindliche Lernprozesse durch die Entwicklung und den Einsatz adäquater digitaler Medien zu ermöglichen und optimal zu unterstützen.The present paper addresses the question how educational apps need to be constructed in order to support learning processes in early childhood. To this end multimedia and digital learning are examined from a cognitive science perspective. Theoretical frameworks suggest that information is processed via two channels in working memory, an auditory and a visual channel. But processing capacities are limited: Essential processing of new information and generative processing integrating new and previously stored knowledge are hampered by resources being deployed to non-essential processing of irrelevant information or the inhibition of such information - contingent to attention control. These and further theoretical assumptions are supported by empirical data. Research findings imply that educational apps should meet certain criteria in order to facilitate and support learning processes: Working memory load needs to be reduced by the omission of irrelevant information and same-channel redundancies as well as by limiting the number of available options. Learning (of complex content) is facilitated by emphasizing essential information, pre-presentation of crucial information and parallel presentation of the same content via both processing channels. Incorporating and spreading these insights from cognitive and learning sciences in the fields of education and app development/information technology has the potential to facilitate and support children’s learning processes

Modification of clonogenic survival and protein phosphorylation by QLT0267 are independent from ILK.

<p>Mouse <i>ILK</i>^fl/fl and <i>ILK^−/−</i> fibroblasts were cultured under 2D or 3D cell culture conditions, exposed to QLT0267 for 24 h plus/minus irradiation (2 Gy X-rays) and basal (A) and radiation cell survival (B) were measured as described under <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006434#s4" target="_blank">Materials and Methods</a>. Results are means±s.d. (n = 3). Student's t-test compared QLT0267-treated <i>ILK</i>^−/− vs. QLT0267-treated <i>ILK</i>^fl/fl cells (A) or QLT0267/irradiated vs. DMSO/irradiated cells (B). *<i>P</i><0.05; **<i>P</i><0.01. (C) Total protein lysates from QLT0267- or DMSO-treated cells were analyzed by SDS-PAGE and Western blotting using indicated antibodies. (D) Cells were transfected with 20 nM ILK-specific siRNA or control siRNA. At 48 h post transfection, efficient downregulation of ILK expression was confirmed by Western blotting. Densitometric values were normalized to β-Actin. (E) For clonogenic assays, siRNA knockdown cell cultures were irradiated with 2 Gy X-rays 48 h after transfection. Results represent means±s.d. (n = 3).</p