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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Etude du rôle de la protéine ADAM9 et de son isoforme sécrétée dans les processus de migration et d’angiogenèse tumoraux / Implication of membrane ADAM9 protein and its secreted form on tumor invasion and angiogenesis

Mongaret, Céline 28 November 2012 (has links)
L’invasion métastatique des tumeurs humaines est un mécanisme complexe qui repose sur l’acquisition de nouvelles fonctionnalités par les cellules tumorales. Les protéines ADAM et plus particulièrement la protéine ADAM9, grâce à leur domaine extracellulaire se composant d’une activité métalloprotéasique et disintégrine, possèdent des fonctions importantes et nécessaires au processus d’invasion. Cependant, les mécanismes de régulation de la protéine restent globalement méconnus dans la pathologie cancéreuse. L’objectif de ce travail a consisté à évaluer le rôle de l’expression d’ADAM9 dans les mécanismes d’agressivité tumorale tels que l’adhérence cellulaire, la migration cellulaire ou l’angiogénèse ainsi que l’étude des mécanismes de régulation de l’expression de cette protéine. Compte tenu du fait que le peroxyde d’hydrogène est connu pour induire l’expression d’ADAM9, les premiers travaux ont eu pour objectif d’établir le lien entre stress oxydant, ADAM9 et adhérence tumorale. L’exposition des cellules d’adénocarcinome pulmonaire au peroxyde d’hydrogène induit une augmentation dose dépendante de l’expression de la protéine ADAM9 transmembranaire et de sa forme sécrétée. Les études in vitro ont permis d’établir que les capacités d’adhérence et d’invasion tumorale induites par le stress oxydant sont principalement médiées par les deux isoformes de la protéine ADAM9. Par ailleurs, l’expression d’ADAM9 provoque un accroissement de la néo-angiogénèse par l’intermédiaire d’un accroissement non transcriptionel de la biosynthèse d’IL8. Cette cytokine proangiogénique va interagir avec le récepteur CXCR2 et va permettre la mise en place d’une néovascularisation in vitro. Le développement d’un modèle de xénogreffe de cellule d’adénocarcinome pulmonaire a permis de confirmer le rôle majeur d’ADAM9 dans les processus de dissémination métastatique et d’angiogénèse tumoraux. L’étude de la modulation pharmacologique d’ADAM9 a reposé sur deux stratégies pharmacologiques différentes : d’une part l’interaction directe avec les différentes isoformes d’ADAM9 au moyen d’un anticorps neutralisant et d’autre part une action sur les mécanismes de transduction cellulaire tels que la protéine SRC ou la protéine kinase C. Ce travail a permis de mieux comprendre l’implication de la protéine ADAM9 au cours du processus de cancérogenèse de part sa participation aux étapes majeures que sont la dissémination métastatique induite par le stress oxydant et l’angiogenèse / Tumor invasion is a complex mechanism that is based on the acquisition of tumor cells new functions. ADAM proteins, especially protein ADAM9, through their extracellular domain consisting of a disintegrin and metalloprotease activity, have important functions and processes necessary for invasion. However, the mechanisms regulating protein remain largely unknown in cancer pathology. The objective of this work was to evaluate the role of ADAM9 expression in tumor aggressiveness such as cell adhesion, cell migration and angiogenesis and to study the mechanisms regulating this protein expression. Given the fact that hydrogen peroxide is known to induce the expression of ADAM9 protein, the first work aimed to establish the relationship between oxidative stress, adhesion and tumor ADAM9 expression. Hydrogen peroxide induces a dose-dependent increase of both expression and activity of ADAM9 on adenocarcinoma pulmonary cells. Oxidative stress induced ADAM9 expression and activity are mainly supported by the secreted form of ADAM9 protein. In vitro studies have shown that capacity of adhesiveness and invasiveness induced by oxidative stress are mainly mediated by the two forms of ADAM9 protein. In addition, ADAM9 protein expression induces neoangiogenesis through increased production of interleukin 8. This proangiogenic cytokine that interacts with the CXCR2 receptor is able to stimulate neovascularization in vitro studies. Development of a lung adenocarcinoma xenograft model confirmed that ADAM9 protein have an important role on metastasis process and tumor angiogenesis. The study of pharmacological modulation of ADAM9 expression was based on two different pharmacological strategies: the first interacts with different isoforms of ADAM9 using a neutralizing antibody and the second strategy modulate cell transduction mechanism such as SRC protein or protein kinase C (PKC). This work aims to understand the involvement of ADAM9 protein during the process of carcinogenesis, such as tumor invasion induced by oxidative stress and neoangiogenesis
12

Análise de um painel de biomarcadores urinários para identificar e prever recidivas de carcinoma urotelial superficial de bexiga / Analysis of panel urinary biomarkers to identify and predict recurrence of superficial bladder urothelial carcinoma

Srougi, Victor 18 January 2019 (has links)
Introdução: O seguimento de pacientes com câncer de bexiga superficial apresenta embargos financeiros e psicológicos ao paciente, devido à realização frequente de exames invasivos. Com fim de substituir ou diminuir os exames invasivos, busca-se biomarcadores urinários acurados, que permitam diagnosticar a recidiva tumoral e estratificar pacientes com maior risco de recidiva futura. O objetivo deste estudo é avaliar se expressão na urina de PAI-1, DJ-1, ApoA-1, MMP-9 e IL-8 permite identificar e antecipar a recidiva de câncer de bexiga. Método: A expressão da PAI-1, DJ-1, ApoA-1, MMP-9 e IL-8 foi mensurada por ELISA na urina de 152 pacientes tratados previamente de carcinoma urotelial superficial de bexiga e em seguimento. Os níveis das proteínas foram comparados entre pacientes com e sem recidiva de câncer de bexiga (1) no momento da coleta de urina e (2) durante o seguimento. A ocorrência de recidiva tumoral foi confirmada por análise histopatológica da biópsia de lesões suspeitas, investigadas quando havia alterações na cistoscopia, ultrassom ou citologia oncótica. Pacientes com recidiva diagnosticada no momento da coleta de urina foram excluídos da análise para avaliar o papel antecipatório das cinco proteínas. Foi avaliado se o uso prévio de BCG intra-vesical exercia influência no nível das cinco proteínas estudadas. Resultados: Entre os pacientes avaliados, 16 (10,5%) apresentaram recidiva de carcinoma urotelial no momento da coleta de urina e 21 (15,4%) apresentaram recidiva de carcinoma urotelial durante o seguimento. O seguimento mediano foi de 47 meses (interquartis de 39 e 50 meses). Um painel para o diagnóstico de recidiva tumoral incluindo três biomarcadores (ApoA-1, MMP-9 e IL-8) apresentou razão de risco de 12,9 (IC 95% =3,5-47,4) e um painel para prever pacientes que desenvolverão recidiva durante o seguimento incluindo dois biomarcadores (PAI-1 e IL-8) apresentou razão de risco de 4,1 (IC 95% =1,4-11,4). Os resultados dos painéis não foram influenciados pelo uso prévio de BCG intra-vesical. Conclusão: Os painéis apresentados permitem identificar pacientes com recidiva de carcinoma urotelial de bexiga e prever quais pacientes terão maior risco de desenvolver recidiva no futuro. O uso prévio de BCG intra-vesical não alterou a expressão dos biomarcadores / Purpose: To evaluate if the urinary levels of PAI-1, DJ-1, ApoA-1, MMP-9 and IL-8 can identify and predict tumor recurrence in patients on follow-up of superficial bladder cancer. Methods: We prospectively analyzed the urine of 152 patients previously treated of superficial bladder cancer on follow-up regimen. Five biomarkers (PAI-1, DJ-1, ApoA-1, MMP-9 and IL-8) were assessed by ELISA and compared among patients with and without bladder cancer recurrence (1) in the moment of urine collection and (2) during follow-up. Tumor recurrence was evaluated with cystoscopy, ultrasound and urine oncotic cytology and confirmed by pathological analysis. Patients with recurrence at urine collection were excluded from prediction analysis. A correlation between the level of the biomarkers and previous use of intravesical BCG was investigated. Results: Median follow-up was 47 months (IQR =39-50 months). Among patients included, 16 (10,5%; N =152) and 21 (15,4%; N =136) had bladder cancer recurrence diagnosed in the moment of urine collection and during follow-up, respectively. The panel to diagnose recurrence including 3 biomarkers (ApoA-1, MMP-9 and IL-8) presented OR =12,9 (CI =3,5-47,4), while the panel to predict patients who will have a recurrence during follow-up including 2 biomarkers (PAI-1 and IL-8) presented OR =4,1 (CI =1,4- 11,4). Previous use of intra-vesical BCG didn\'t influence urine biomarkers expression. Conclusions: The 3-biomarker panel can be used to identify patients with bladder cancer recurrence. The 2-biomarker panel can be used to predict patients at greater risk of bladder cancer recurrence during follow-up. Both are reliable in patients with previous use of intravesical BCG

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