O objetivo do estudo foi confirmar se a redução da fecundidade dos mosquitos Aedes aegypti infectados por Plasmodium gallinaceum ocorre por morte das células foliculares dos ovários. Mosquitos infectados produzem menos ovos quando comparado aos mosquitos sadios. Uma explicação é a redução da viabilidade celular que ocorre nos ovários de fêmeas 18, 22 e 24 horas após o repasto sanguíneo infectado (RSI) como foi observado pela técnica MTT. Utilizando o acridine orange, não foi possível observar a morte das células foliculares no intervalo de 18 horas, mas 22 e 24 horas após o RSI essas células estão em morte em relação ao mesmo intervalo do repasto sanguíneo controle (RSC). A análise do DNA fragmentado foi realizada através do TUNEL. Ovários de 22 e 24 horas após RSC e RSI foram negativos nas regiões dos cortes histológicos examinados. Sendo assim, podemos concluir que, utilizando esses ensaios foi possível identificar a morte das células foliculares como uma resposta a redução da fecundidade, porém não foi possível determinar que o tipo de morte é apoptose. / The objective of this study was to confirm the hypothesis that the fertility reduction in Plasmodium gallinaceum-infected Aedes aegypti occurs by follicular cells death. A significant reduction in the number of eggs laid by infected mosquitoes was confirmed. It was observed a reduction of viable cells in 18, 22 and 24 hours PBM infected by MTT assay. It was not possible to observe cell death in ovary tissue 18 hours PBM infected, but the follicular cells showed orange color 22 and 24 hours indicating they are in death in relation to the same interval of PBM control. To determine if these cells exhibit apoptosis, we use the TUNEL which mark the fragmented DNA, a characteristic of the apoptosis process. Ovaries 22 and 24 hours PBM infected and control were negative for TUNEL marker from ovary histological preparations. Thus, we conclude that fecundity reduction occurs as a response to follicular cells death caused by P. gallinaceum infection but it was not possible to affirm if the type of follicular cells death is apoptosis.

Orientador: Hélio Amante Miot / Coorientador: Mariângela Esther Alencar Marques / Resumo: O carcinoma basocelular (CBC) é a neoplasia maligna mais comum entre os homens e sua incidência está aumentando em nosso meio. Pode se manifestar como lesão nodular, superficial, esclerodermiforme, micronodular e fibroepitelioma de Pinkus. O CBC é um carcinoma de baixa mortalidade, porém com elevada morbidade devido ao potencial destrutivo local e às elevadas taxas de reincidência. As diferenças evolutivas dos diversos tipos de carcinomas basocelulares não são bem definidas. A análise de fatores de proliferação e apoptose pode subsidiar o conhecimento sobre a fisiopatologia e as diferenças evolutivas dessas lesões. A literatura revela a escassez de investigações sobre a expressão diferencial de fatores de proliferação (Ki-67) e relacionados à apoptose (p53, survivina e NF-kB-p105) dos diferentes subtipos de carcinomas basocelulares e ainda tumores recidivados. O objetivo desse estudo é avaliar a expressão de marcadores de proliferação celular e apoptose em carcinomas basocelulares dos tipos nodular, superficial, esclerodermiforme e tumores recidivados. Foram selecionados subtipos histológicos únicos, como forma de tentar compreender o comportamento dos CBCs individualmente. As lâminas desses espécimes foram submetidas ao protocolo de marcação imuno-histoquímica. Foram estudadas 100 amostras, sendo 50 unidades de epiderme normal e as demais distribuídas entre cada subtipo tumoral. O padrão de marcação de cada marcador sobre os diferentes tipos de tecidos foi avaliado a partir ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Basal cell carcinoma (BCC) is the most common malignant neoplasm among men and its incidence is increasing in our country. It can manifest as nodular, superficial, sclerodermiform, micronodular and Pinkus fibroepithelioma lesions. BCC is a lowmortality carcinoma, but with high morbidity due to local destructive potential and high rates of recurrence. The evolutionary differences of the various types of basal cell carcinomas are not well defined. The analysis of proliferation and apoptosis factors may support knowledge about the pathophysiology and evolutionary differences of these lesions. The literature reveals the scarcity of investigations on the differential expression of proliferation factors (Ki-67) and related apoptosis (p53, survivin and NF-kB-p105) of the different subtypes of basal cell carcinomas and recurrent tumors. The aim of this study is to evaluate the expression of markers of cell proliferation and apoptosis in basal cell carcinomas of the nodular, superficial, sclerodermiform and recurrent tumors. Unique histological subtypes were selected as a way to attempt to understand the behavior of individual BCCs. The slides of these specimens were submitted to the immunohistochemical labeling protocol. A total of 100 samples were studied, being 50 normal epidermal units and the others distributed between each tumor subtype. The marking pattern of each marker on the different tissue types was evaluated from generalized linear models (GLMs) followed by Sidak post-hoc test, when necessary. Statiscally significant differences (p<0,01) in the immunostaining of different tissue types were found for the Ki-67, p53 and survivin markers, but not for the p105 marker (p=0,21). The Ki-67 marker was more expressed in sclerodermiform than in epidermal and nodular cells. Immunoblotting of p53 was less expressed in the epidermis than in superficial subtypes and relapses, and also less expressed in... (Complete abstract click electronic access below) / Doutor

Orientador: Márcia Guimarães da Silva / Resumo: O parto prematuro espontâneo, definido como nascimento antes das 37 semanas completas de gestação, apesar dos consideráveis avanços científicos, ainda representa um importante problema médico, humano e social. É representado por dois grandes grupos de patologias obstétricas definidas como Trabalho de Parto Prematuro (TPP) e Rotura Prematura de Membranas Pré-Termo (RPM-PT). O primeiro objetivo deste estudo foi avaliar os níveis de 8-oxo-2'-desoxiguanosina (8-OHdG) em membranas corioamnióticas de gestações complicadas pela prematuridade. Neste estudo transversal, foram estudadas 34 membranas corioamnióticas de gestações complicadas por TPP e 39 de gestações complicadas por RPM-PT, cujos partos ocorreram no período compreendido para a prematuridade. Como grupo controle foram incluídas no estudo 44 membranas corioamnióticas de partos a termo. As membranas corioamnióticas foram coletadas e a extração total de DNA foi realizada pelo Kit genomic-Prep Mini Spin e os níveis de 8-OHdG níveis foram analisados pela técnica de ELISA empregando-se o kit Highly Sensitive 8-OHdG. Em relação aos dados obtidos, os níveis de 8-OHdG nas membranas corioamnióticas do grupo termo foram significativamente maiores que nos grupos prematuros (p<0,001). Os níveis de 8-OHdG foram também mais elevados no grupo de termo do que nos grupos PTL ou RPM-PT (p<0,001), respectivamente. Nossos dados reforçam a tese que os danos oxidativos estão presentes nas membranas corioamnióticas de gestações a termo como cons... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Spontaneous preterm birth, defined as birth before 37 weeks completed gestation, despite the considerable scientific advances, still represents an important medical problem, human and social. It is represented by two large groups of obstetric pathologies defined as preterm labor (PTL) and premature rupture of preterm ovular membranes (pPROM). The first objective of this study was to evaluate the levels of 8-oxo-2'-deoxiguanosine (8-OHdG) in amniochorion membranes from pregnancies complicated by prematurity. In this crosssectional study, were enrolled 31 with PTL and 35 with pPRM who presented preterm delivery. As control group was included 37 pregnant women that delivery at term. Amniochorion membranes were collected and total DNA extraction was performed by ILLUSTRA tissue & cells genomic-Prep Mini Spin Kit and 8-OHdG levels were measured by an ELISA Highy Sensitive 8-OHdG Check kit. Regarding to data, 8-OHdG levels in amniochorion membranes of term group (2,90 ng/mL [min: 1,54 - max:4,06]) were significantly higher than premature group (0,61 ng/mL [min: 0,37 - max:0,91]) (p<0.001). 8- OHdG levels were also higher in term group than in PTL (0,71 ng/mL [min: 0,40 - max:1,47]) or pPROM groups (0,53 ng/mL [min: 0,37 - max:0,71]) (p<0.001), respectively. Our data reinforces that oxidative damage are present at term pregnancies as physiologic process of amnionchorion aging. The second objective of this study was to analyze the association among histologic chorioamnionitis, apoptosis occurence and 8-OHdG levels in amniochorion membranes from pregnancies complicated by pPROM and PTL. It was a prospective study and a total of 60 pregnant women were enrolled, being 31 pregnant women who presented pPROM and 29 with PTL. After delivery, the amniochorion membranes were subjected to a histopathological examination, to 8-OHdG levels analysis by an ELISA... (Complete abstract click electronic access below) / Doutor

Beatmungsinduzierte Lungenschädigung stellt eine häufige Komplikation bei der Behandlung von ALI / ARDS dar. Selbst kleinere, bereits als protektiv bezeichnete Tidalvolumina können so auf dem Boden einer bereits stark beeinträchtigten Lunge zur einem starken lokalen Entzündungsgeschehen im alveolären Gewebe führen, in dessen weiteren Verlauf es zu einer mechanisch induzierten Apoptose und Nekrose kommen kann. Die Apoptose, auch als programmierter Zelltod bezeichnet, kann auf ihrem extrinsischen Weg über eine Ligand / Rezeptor Interaktion ausgelöst oder gehemmt werden. Dies macht das Zellsterben auf molekularer Ebene in gewisser Weise steuerbar, was sich präventiv und therapeutisch-medikamentös zu Nutze machen ließe. Daher soll in dieser Arbeit untersucht werden, ob bei der mechanisch induzierten Apoptose von Typ II-Pneumozyten durch unphysiologische Beatmung ebenfalls klassische Marker einer extrinsischen Apoptose zu finden sind und welche Rolle sie im Prozess der dehnungsinduzierten Apoptose spielen. Diese Untersuchungen wurden an frisch isolierte Typ II-Pneumozyten aus der Sprague-Dawley-Ratte durchgeführt. Die Zellen wurden auf elastischen 6-Well Platten jeweils 24h bei unphysiologischen (Frequenz 40 / Amplitude 30) auf der Flexercell FX-3000 Dehnmaschine gedehnt und im Anschluss mittels ELISA und Western-Blot auf Marker der extrinsischen Apoptose hin untersucht. Dabei konnte eine mäßige Erhöhung der für den extrinsischen Apoptoseweg typischen, jedoch mit ihm nicht zwangsläufig assoziierten Caspase-8 und TNF-α ermittelt werden. Für die Marker FAS, FAS-L und FADD, die eindeutig für den extrinsischen Apoptoseweg stehen, konnte keine Konzentrationserhöhung nach mechanischer Dehnung nachgewiesen werden. Diese Ergebnisse, frühere Forschungsergebnisse aus unserer Forschungsgruppe und die weltweite Studienlagen lassen somit den Schluss zu, dass die extrinsische Apoptose bei mechanischer Dehnung von Typ II-Pneumozyten keine entscheidende Rolle spielt.

Orientador: Wellerson Rodrigo Scarano / Coorientador: Luis Fernando Barbisan / Banca: Sebastião Roberto Taboga / Banca: Raquel Fantin Domeniconi / Resumo: Sabe-se que fatores ambientais e de estilo de vida, tais como a dieta, são capazes de induzir significativas mudanças na concentração e no metabolismo dos hormônios esteroides, o que pode contribuir para o desenvolvimento de doenças prostáticas. O Bisfenol A (BPA) é um componente dos produtos a base de resinas epóxi e plásticos policarbonato e tem sido investigado por sua provável atividade carcinogênica para a mama e próstata. O objetivo geral desse trabalho foi investigar se a exposição gestacional ao BPA suplementado ou não com Indol-3-Carbinol (I3C), um composto natural com propriedades quimioprotetoras, interfere no padrão de desenvolvimento da próstata, bem como na suscetibilidade ao desenvolvimento de lesões prostáticas. Fêmeas prenhes da linhagem Sprague-Dawley foram divididas em 5 grupos experimentais: G1: Controle (ração basal); G2: BPA25 (25μg/Kg); G3: BPA25 (25μg/Kg) + I3C; G4: BPA250 (250μg/Kg); G5: BPA250 (250μg/Kg) + I3C. Machos selecionados de diferentes ninhadas (2/ninhada) foram eutanasiados no DPN21 para avaliação imediata sobre a morfogênese prostática e no DPN180 para avaliação dos efeitos tardios.No DPN21 e DPN180 os animais foram eutanasiados por decapitação, o sangue foi coletado para análises hormonais e os hemilobos ventrais direitos separados para rotina histológica, análise estereológica e imuno-histoquímica, e os esquerdos congelados em nitrogênio líquido para o Western Blot. O lobo dorsolateral foi coletado no DPN180 para avaliação histopatológica. O peso do lobo ventral da próstata reduziu no grupo G5 em relação a G4, enquanto no DPN180 não houve diferença nesse parâmetro. Com relação à estereologia no DPN21 evidenciou-se aumento do compartimento epitelial e diminuição do compartimento luminal nos grupos G3 e G5. Quanto ao índice de proliferação celular no DPN21 observou-se aumento nos grupos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Environmental factors and life style, such as diet, are able to induce significant changes in the concentration and metabolism of steroid hormones and can contribute with prostatic diseases development. Bisphenol A (BPA) is an organic compound used to make epoxy resins and polycarbonate plastics and has been investigated for its probable carcinogenic activity for breast and prostate. The aim of this study was to investigate if gestational exposure to BPA, supplemented or not with Indole-3-Carbinol (I3C), a natural compound with chemoprotective properties, can modify the prostate development pattern as well as the susceptibility to develop lesions in prostate. Sprague-Dawley pregnant females were divided into five experimental groups: G1: Control (basal chow); G2: BPA25 (25μg/Kg) G3: BPA25 (25μg/Kg) + I3C; G4: BPA250 (250μg/Kg); G5: BPA250 (250μg/Kg) + I3C. Selected males from different litters (2/litter) were euthanized in PND21, to study the early effects on prostate morphogenesis and in PND180 to evaluate the late effects. At PND21 and PND180 the animals were euthanized by decapitation, blood was collected to hormone assays and right ventral lobule was used for histopathological evaluation, stereological analysis, immunohistochemistry and TUNEL assay, and the left ventral lobule was frozen and stored in the -80oC freezer for Western Blot analysis. Dorsolateral lobe was collected for histopathologic evaluation at PND180 animals. Prostatic ventral lobe weight at PND21 decreased in the G5 group compared to G4, while at PND180 there was no significant difference in this parameter. At PND21 there was increase in epithelial compartment and decrease in the luminal compartment in G3 and G5 compared to G1. Epithelial cells proliferation index at PND21 was significant higher in G2 and G3 than G1, and apoptosis index in I3C groups (G3 e G5) was higher in relation... (Complete abstract click electronic access below) / Mestre

Mit einer weltweiten Inzidenz von etwa 600.000 Neuerkrankten pro Jahr gehört das orale Plattenepithelkarzinom zu den sechs häufigsten malignen Tumorerkrankungen des Menschen. Zur Behandlung operabler Tumoren der Stadien III-IVb hat sich hingegen die multimodale Therapie mit primär operativem Vorgehen, gegebenenfalls mit nachfolgender adjuvanter Radiatio beziehungsweise Radiochemotherapie, etabliert. Beim Vorhandensein von Fernmetastasen hingegen ist das Therapiekonzept als palliativ einzustufen. Während sich für die adjuvante, kurativ intendierte Radiochemotherapie die Verwendung von Cisplatin oder cisplatinhaltiger Wirkstoffe etabliert hat, stellen seit einigen Jahren selektive Wirkstoffe wie Nivolumab und Cetuximab eine Alternative zur Cisplatin-Anwendung im palliativen Setting dar. Für die medikamentöse Therapie des fortgeschrittenen oralen Plattenepithelkarzinoms scheinen daher neue rationale Therapieansätze notwendig zu sein. Besonders ein hohes Maß an Toxizität sowie die individuelle Resistenzbildung vermögen den Therapieerfolg der herkömmlichen Chemotherapie zu kompromittieren. Spezifisch wirksame sogenannte "targeted agents" binden RTK und blockieren somit die nachgeschaltete Signalkaskade. In der vorliegenden Studie kam es zur Anwendung der TKI Afatinib, Volasertib und Nintedanib in alleiniger Anwendung sowie Kombinationstherapie mit Cisplatin und dem Smac-mimetic LCL-161. Die Analyse der Wirksamkeit oben genannter Stoffe erfolgte durch eine In-vitro-Evaluation an fünf Zelllinien des humanen Plattenepithelkarzinoms der Kopf- und Halsregion. Nach semiquantitativem Expressionsnachweis der Zielstrukturen erfolgte die Stimulation der Zellen mittels spezifischer Verdünnungsreihen in Mono- und Kombinationstherapie. Folgend wurden auf der Basis von Zellzahlanalysen, Kristallviolettassays und der Erstellung von Dosis-Wirkungskurven zelllinienspezifische IC50- beziehungsweise IC20-Werte ermittelt, statistisch ausgewertet und miteinander verglichen. Die Anwendung von Afatinib in Monotherapie zeigte in der vorliegenden Studie keine signifikant erhöhte Zytoreduktion im Vergleich zur alleinigen Anwendung von Cisplatin. Auch ein Zusatz von Cisplatin zur Anwendung ergab keinen erwarteten synergistischen Effekt. Die Anwendung von Nintedanib in Monotherapie zeigte in der Analyse keine signifikanten Vorteile gegenüber einer alleinigen Cisplatinanwendung. Auf der Basis der Ergebnisse der vorausgegangenen Expressionsanalysen scheint der FGFR-2 eine übergeordnete Rolle zu spielen, da hier partiell von einer verstärkten Wirksamkeit auszugehen ist. Weiterhin scheint gegenüber selektiven Angiogeneseinhibitoren kein Vorteil für Nintedanib zu bestehen. Betrachtet man die Kombinationsanwendung von Nintedanib mit Cisplatin so fallen sowohl synergistische wie auch partiell antagonistische Effekte im Vergleich zur Cisplatin-Monotherapie auf. Diese können durch die heterogene Expression der Zielstrukturen allein nicht erklärt werden, sodass hier weiterführende Untersuchungen sinnvoll wären. Bei der Anwendung von Volasertib konnte für alle Zelllinien eine sehr deutliche Zytoreduktion erzielt werden, was durch generell erhöhte Expressionsraten erklärbar scheint. Sie manifestierte sich zudem in deutlich erniedrigten mittleren inhibitorischen Konzentrationen der Monotherapie gegenüber einer alleinigen Cisplatin-Anwendung. Betrachtet man die Kombinationsanwendung von Volasertib mit Cisplatin imponierten für alle Zelllinien erstaunlicherweise sogar schlechtere Ansprechraten verglichen mit der Volasertib-Monotherapie. Hier könnte man von einer inhibierenden Wechselwirkung der Wirkstoffe ausgehen. Diese Tatsache macht weiterführende Untersuchung zur Anwendung von Volasertib in Monotherapie attraktiver als die jeweilige Kombinationsanwendung. Die Kombinationsanwendungen von LCL-161 mit Afatinib beziehungsweise Volasertib wiesen keine signifikant erhöhten zytoreduktiven Effekte auf. Hingegen waren die Untersuchungsergebnisse der Kombinationsanwendung des verwendeten Smac-Analogons und Nintedanib bemerkenswert. In vier von fünf Zelllinien sorgte ein LCL-161-Zusatz für eine signifikant erhöhte Zytoreduktion. Eine zusätzlich zur Angiogeneseinhibition durch Nintedanib induzierte Apoptoseinduktion in Kombination mit der Apoptosesensibilisierung durch LCL-161 könnte eine mögliche Erklärung dieser Beobachtung darstellen. Aufgrund der sehr heterogenen Ergebnisse dieser Studie mit partiell synergistischen aber auch antagonistischen Effekten lässt sich schlussfolgern, dass alle drei verwendeten TKI aktuell keine vielversprechende Alternative zu der herkömmlichen Chemotherapie darstellen. Diese Heterogenität verdeutlicht auch, dass die Suche nach individuellen, zielgerichteten medikamentösen Therapieansätzen essenziell bleibt. Hierbei könnten Smac-Analoge ein vielversprechendes Feld weiterführender experimenteller und klinischer Studien eröffnen. / With a worldwide incidence of about 600,000 new cases per year, oral squamous cell carcinoma is one of the six most common malignant human tumors. For the treatment of operable stage III-IVb tumors, however, multimodal therapy with primarily surgical procedures, possibly followed by adjuvant radiotherapy or radiochemotherapy, has become established. In the presence of metastases the therapy concept is classified as palliative. While the use of cisplatin or 5-FU has become established for adjuvant, curative radiochemotherapy, selective drugs such as nivolumab and cetuximab have been an alternative to the use of cisplatin in the palliative setting for several years. New rational therapeutic approaches appear to be necessary for the drug therapy of advanced oral squamous cell carcinoma. In particular, a high degree of toxicity and the individual development of resistance may compromise the therapeutic success of conventional chemotherapy. Specifically so-called "targeted agents" bind RTK and thus block the downstream signaling cascade. In the present study, TKI afatinib, volasertib and nintedanib were used alone as well as in combination therapy with cisplatin and the smac-mimetic LCL-161. The analysis of the efficacy of the above mentioned agents was performed by in vitro evaluation of five cell lines of human squamous cell carcinoma of the head and neck region. After semi-quantitative expression detection of target structures, the cells were stimulated using specific dilution series in mono- and combination therapy. Subsequently, cell line-specific IC50 or IC20 values were determined, statistically evaluated and compared on the basis of cell number analyses, crystal violet assays and the preparation of dose-response curves. The use of afatinib in monotherapy did not show a significantly increased cytoreduction in the present study compared to cisplatin alone. The addition of cisplatin to the treatment did not result in an expected synergistic effect either. In the analysis, the use of nintedanib as a monotherapy did not show any significant benefit over cisplatin alone. Based on the results of the previous expression analyses, FGFR-2 appears to play an overriding role as it is expected to partially increase efficacy. Furthermore, nintedanib does not appear to have an advantage over selective angiogenesis inhibitors. When nintedanib is used in combination with cisplatin, both synergistic and partial antagonistic effects are observed compared to cisplatin monotherapy. These cannot be explained by the heterogeneous expression of the target structures alone, so that further investigations would be useful here. When applying Volasertib, a very significant cytoreduction could be achieved for all cell lines, which seems to be explained by generally increased expression rates. It also manifested itself in significantly lowered mean inhibitory concentrations of monotherapy compared to cisplatin alone. When considering the combination of Volasertib with cisplatin, surprisingly, the response rates of all cell lines were even worse compared to Volasertib monotherapy. Here, one could assume an inhibitory interaction of the substances. This fact makes further investigation of the use of Volasertib in monotherapy more attractive than the respective combination treatment. The combination of LCL-161 with afatinib or volasertib did not show significantly increased cytoreductive effects. However, the results of the combination treatment of the Smac-mimetic and nintedanib were remarkable. In four out of five cell lines, LCL-161 supplementation resulted in significantly increased cytoreduction. An additional apoptosis induction induced by nintedanib in addition to angiogenesis inhibition in combination with apoptosis sensitization by LCL-161 could be a possible explanation for this observation. Due to the very heterogeneous results of this study with partially synergistic but also antagonistic effects, it can be concluded that all three TKI used currently do not represent a promising alternative to conventional chemotherapy. This heterogeneity also illustrates that the search for individual, targeted drug therapy approaches remains essential. Here, Smac-analogues could open up a promising field for further experimental and clinical studies.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Entzündliche Prozesse stellen einen zentralen Aspekt der Karzinogenese dar und können sowohl zur Induktion als auch zum Progress von Tumoren beitragen. Der NF-kB-Signalweg ist einer der wichtigsten Signaltransduktionswege der In- flammation und Tumorpromotion, was ihn zur plausiblen Zielstruktur für die pros- pektive klinische Tumortherapie machen könnte. In der vorliegenden Arbeit wur- den die Eigenschaften von vier unterschiedlich targetierenden NF-kB-pathway- Inhibitoren – Cortisol, MLN4924, QNZ und TPCA1 – auf die Inflammation, Zell- proliferation und proapoptotische Sensitivierung am in vitro Modell des HNSCC untersucht. Es konnte gezeigt werden, dass die spezifische Auswahl des Inhi- bitors bzw. seines targets entscheidend für den wirkungsvollen Einsatz dieser Wirkstoffgruppe in der antiproliferativen Therapie des HNSCC zu sein scheint. Beispielsweise vermittelte MLN4924 die Freisetzung von IL-8. Cortisol bewirkte die Resistenz der FasL-induzierten Apoptose von HNSCC-Zellen. QNZ wirkte in einigen Zelllinien antiproliferativ und sensitivierend für den FasL-induzierten Zell- tod, beeinflusste jedoch in diesem Zusammenhang kontraproduktiv die IL-8-Sek- retion. Dies disqualifizierte diese Wirkstoffe für die Anwendung in der Therapie von Kopf-Hals-Tumoren. Dahingegen qualifizierte sich TPCA-1 aufgrund folgen- der Eigenschaften als geeigneter Wirkstoff für den prospektiven klinischen Ein- satz: 1) TPCA-1 wirkte antiproliferativ, 2) hemmte die TNF-a-induzierte Inflammation, 3) regulierte die IL-8-Expression herab, 4) wirkte sensitivierend für den TNF-a-induzierten Zelltod, 5) interferierte kaum mit der FasL-vermittelten Apoptose und 6) induzierte Apoptose. / Inflammatory processes represent a central aspect of carcinogenesis and may contribute to both tumour induction and progression. The NF-kB signalling pathway is one of the most important signal transduction pathways in inflammation and tumour promotion, which could make it a plausible target for prospective clinical tumour therapy. In the present study, the properties of four different targeting NF-kB pathway inhibitors - cortisol, MLN4924, QNZ and TPCA1 - on inflammation, cell proliferation and proapoptotic sensitivity were investigated in an in vitro model of HNSCC. It was shown that the specific selection of the inhi- bitor or its target seems to be crucial for the effective use of this group of drugs in the antiproliferative therapy of HNSCC. For example, MLN4924 mediated the release of IL-8, and cortisol induced the resistance of FasL-induced apoptosis of HNSCC cells. QNZ had an antiproliferative effect in some cell lines and was sensitive to FasL-induced cell death, but counteracted IL-8 secretion in this context. This disqualified these agents for use in the therapy of head and neck tumours. In contrast, TPCA-1 qualified as a suitable agent for prospective clinical use due to the following properties: 1) TPCA-1 had an antiproliferative effect, 2) inhibited TNF-a-induced inflammation, 3) down-regulated IL-8 expression, 4) was sensitive to TNF-a-induced cell death, 5) hardly interfered with FasL-mediated apoptosis, and 6) induced apoptosis.

Tableau d'honneur de la Faculté des études supérieures et postdoctorales, 2006-2007 / Remodeling of mitochondria is a dynamic process coordinated by fusion and fission of the inner and outer membranes of the organelle, mediated by a set of conserved proteins. In metazoans, the molecular mechanism behind mitochondrial morphology has been recruited to govern novel functions, such as development, calcium signaling, and apoptosis, which suggests that novel mechanisms should exist to regulate the conserved membrane fusion/fission machinery. Here we show that phosphorylation and cleavage of the vertebrate-specific PP domain of the mammalian presenilin-associated rhomboid-like (PARL) protease can influence mitochondrial morphology. Phosphorylation of three residues embedded in this domain, Ser-65, Thr-69, and Ser-70, impair a cleavage at position Ser77|Ala78 that is required to initiate PARL-induced mitochondrial fragmentation. Our findings reveal that PARL phosphorylation and cleavage impact mitochondrial dynamics, providing a blueprint to study the molecular evolution of mitochondrial morphology. / Le remodelage de la morphologie et de la structure de des cristae des mitochondries est un processus dynamique régulé par un ensemble conservé de protéines qui coordonnent la « fusion » et la « fission » de la membrane interne et externe de l'organelle. Pendant l'évolution des métazoaires, les mécanismes moléculaires qui contrôlent ces processus ont été recrutés pour régler de nouvelles fonctions, tels le développement, la signalisation du calcium, et l'apoptose. Ceci suggère donc que des mécanismes, toujours inconnus, doivent exister pour réguler la machinerie de la fusion/fission des membranes mitochondriales. Dans cette étude nous démontrons que la phosphorylation et le clivage d'un domaine de la protéase rhomboide PARL (presenilin-associated rhomboid-like), lequel est présent uniquement chez les vertébrés règlent la morphologie des mitochondries. Nous montrons que la phosphorylation de trois acides aminés conservés dans ce domaine, la Ser-65, la Thr-69 et la Ser-70, empêche un clivage aux positions Ser77-Ala78 qui est requis pour initier la fragmentation mitochondriale induite par PARL. Nos résultats démontrent que la phosphorylation et le clivage de PARL ont un impact sur la dynamique des mitochondries, ce qui nous fournit un modèle pour étudier l'évolution moléculaire de la morphologie des mitochondries.