Made available in DSpace on 2015-04-11T14:02:53Z (GMT). No. of bitstreams: 1 karla suguiyama.pdf: 1067694 bytes, checksum: e8bdd19b3cdfa62bbfeeced3b2620b44 (MD5) Previous issue date: 2010-02-26 / Não informado / The Internet has become one of the major media outlets for advertising markets, by exposing its products and services to large audiences at relatively low cost. The main approach of Web advertising is the search advertising whereby ads are selected based on the keywords extracted from the user s search queries submitted to search engines and are matched against keywords associated with ads provided by advertisers, known as a non-intrusive technique called keyword-targeted advertising. The success of keyword-targeted advertising has motivated information gatekeepers to disseminate their ad services over different contexts, such as, content pages and pages of services, leading to the emergence of content-targeted advertising which refers to the issue of matching ads to a web page which is browsed. The impact of advertising on the Web is even greater if we consider the significant increase of their audience, resulting from the proliferation of the material generated by the users in the so-called Web 2.0, specially with the spread of blogs, social networking sites and wikis. Many websites have been highlighted in this context, achieving great popularity and becoming promising sources for advertising, for instance, the video sharing websites, where users can share digital media. In this research, we were trying to investigate alternatives for advertisement selection that would run during the display of on-line videos. In order to avoid the high cost of image processing, we were aiming to explore textual metadata related to videos stored on video sharing websites, through a preliminary study on the usefulness of metadata as a source of information used in the selection of on-line advertisement. While maintaining a video collection and a real ad collection, video metadata was used in experiments with two ad ranking methods: the vector and the vector with the implementation of a block importance model which is based on statistical data and gives a weight to each metadata to estimate the importance of the information carried. In order to evaluate the output of the studied advertisement selection systems, a reference collection containing 81 videos was created. These videos were carefully analyzed in order to determine which products and/or services they could potentially advertise. Based on the information gathered, advertisements were manually picked and thus potentially considered either relevant or irrelevant for their appropriate video contained in the collection. The experimental results obtained showed that the metadata which rather describes video content information, such as its description, potentially offered a greater contribution to the selection of advertisement to be shown during its display. It could also be seen that the application of weights that worked according to the studied block importance model, provided gains of approximately 7% over the vector method that did not use the weights application model. This aspect must be considered important due to the possibility of increasing the profitability of the advertisement selection systems, and given the negative impact of non-relevant advertisement based on credibility and brand of advertisers. / O mercado de publicidade tem encontrado na Web uma das principais mídias para exposição de seus produtos e serviços para um público abrangente a custos relativamente baixos. A principal abordagem de publicidade na Web é a propaganda de busca cujos anúncios são selecionados com base nos termos de consultas feitas por usuários em máquinas de busca e são exibidos junto com as suas respostas, uma técnica não intrusiva conhecida como keyword-targeted advertising (propaganda direcionada baseada em palavra-chave). O sucesso deste formato de publicidade, motivou grandes mediadores de informação a disseminá-lo em vários outros contextos, tais como páginas de conteúdo e páginas de serviços, levando ao surgimento da content-targeted advertising (propaganda direcionada baseada em conteúdo). O impacto da publicidade na Web é ainda maior se considerarmos o aumento expressivo de sua audiência, resultante da proliferação de material gerado pelos próprios usuários finais na chamada Web 2.0, tais como, a disseminação de blogs, redes sociais e wikis. Muitos sites têm-se destacado nesse âmbito, atingindo uma grande popularidade e tornando-se fontes promissoras para a publicidade, entre eles, os sites de compartilhamento de vídeos, nos quais os usuários podem disponibilizar seus próprios vídeos para outros usuários. Neste trabalho procurou-se investigar alternativas para a seleção de anúncios a serem veiculados durante a exibição de vídeos postados na Web. Diferente de trabalhos anteriores, com o intuito de evitar o alto custo de processamento de imagens, buscou-se explorar metadados textuais relacionados aos vídeos disponibilizados pelos sites de compartilhamento destes, através de um estudo preliminar sobre a utilidade dos metadados como fonte de informação a ser usada na seleção de anúncios. Através de uma coleção de vídeos e uma coleção real de propagandas, os metadados dos vídeos foram utilizados em experimentos com dois métodos de ordenação de propagandas: o vetorial e o vetorial com a aplicação de um modelo de importância de blocos que baseado em dados estatísticos, atribui peso a cada metadado visando estimar a importância da informação carregada pelo mesmo. Para a avaliação dos resultados dos sistemas de seleção de propagandas estudados, foi criada uma coleção de referência contendo 81 vídeos. Cada vídeo foi assistido e analisado para a determinação de quais produtos e/ou serviços poderiam ser sugeridos durante a veiculação do mesmo. Baseadas nessas informações, foram selecionadas e associadas manualmente propagandas consideradas relevantes ou não-relevantes para cada vídeo da coleção. Os resultados experimentais obtidos revelaram que os metadados que discorrem mais sobre o conteúdo do vídeo, como a sua descrição, podem oferecer uma contribuição maior para a seleção de anúncios relevantes a serem mostrados durante à exibição do vídeo. Também pôde-se constatar que a aplicação dos pesos de acordo com o modelo de importância de blocos estudado, levou a resultados com um ganho de cerca de 7% em relação ao método vetorial sem a aplicação de pesos. Aspecto que deve ser considerado importante devido a possibilidade de um aumento da lucratividade do sistema de seleção de propagandas e devido ao impacto negativo que a veiculação de um anúncio não-relevante pode causar nos usuários.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-06-09T20:26:25Z No. of bitstreams: 2 Tese - Marco Júnio Peres Filho - 2014.pdf: 2890867 bytes, checksum: 94c9616394d6a389aadabf3d9a0b128c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-06-12T12:31:24Z (GMT) No. of bitstreams: 2 Tese - Marco Júnio Peres Filho - 2014.pdf: 2890867 bytes, checksum: 94c9616394d6a389aadabf3d9a0b128c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-12T12:31:24Z (GMT). No. of bitstreams: 2 Tese - Marco Júnio Peres Filho - 2014.pdf: 2890867 bytes, checksum: 94c9616394d6a389aadabf3d9a0b128c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-04-30 / The impact of Nanotechnology is constantly raising in different areas of science, with the development of new products that bring benefits in comparison with the alternatives available in the market. When encapsulated in nanoparticles, anticancer drugs can achieve several advantages, most importantly the possibility of reducing the amount of drug administered through targeting strategies, which are not accomplished by conventional medication. Passive targeting is related to leaky vasculature in pathological sites, and active targeting comprehends the attachment of specific ligands, anchored in nanoparticles surface, to recognize and bind receptors overexpressed in cancer cells. Coencapsulation of anticancer drugs in the same pharmaceutical carrier can coordinate pharmacokinetics of encapsulated drugs. In the present work, liposomal formulations targeted to folate receptor with paclitaxel (PTX) and imatinib (IB) coencapsulated were obtained, aiming to combine cytotoxic and antiangiogenic effects of the drugs, respectively. New analytical method was developed and validated for simultaneous quantification of IB and PTX. Soy phosphatidylcholine liposomes were prepared, with cholesterol and DSPEmPEG( 2000), to obtain long circulation particles. DSPE-PEG(2000)-FA was obtained by an unpublished method of synthesis, and this product was further used in the formulation by post-insertion technique. Cytotoxic effect and VEGF gene suppression were studied in vitro in two different cell lines, MCF7 (breast adenocarcnioma) and PC3 (prostatic adenocarcinoma), after treatment with liposomal vesicles. Analytical procedures were developed with isocratic elution, 6,5 minutes runs, with linearity, specificity, precision and accuracy. Quantification limit was 750 Ng/mL and 1000 Ng/mL for IB and PTX, respectively. After extrusion, liposomes had mean diameter close to 100 nm and low polidispersion index. Post-insertion of folic acid attached to lipid anchor procedure increased polidispersion, because the procedure lasted 24h. Drug to lipid ratios were 1:26 and 1:27 (IB and PTX respectively). Lyophilized formulations containing trehalose remained stable after 60 days of storage in terms of %EE. Synthesis of DSPE-PEG(2000)-FA was confirmed by RMN, FT-IR and ESIMS techniques. Liposomal PTX was more cytotoxic (p<0,05) than free drug in MCF7 cell line, after both 24h and 48h of exposion, for all tested concentrations. Targeted formulation containing folic acid ligand, had more impact on cell viability reduction (p<0,05) than non targeted liposomes (LPIP), also after 24h. On PC3 cell line cell viability reduction was greater (p<0,01) when the cells were exposed to targeted vesicles loaded with 1 and 10 Ng/mL of IB and PTX, after 24 and 48h. VEGF gene expression was reduced in MCF7 and PC3 (p<0,05), and once more targeted vesicles showed better results than non-targeted liposomes. It is, thus, plausible to conclude, through in vitro experiments results, that the attachment of folic acid to liposomal formulations, resulting in multi-functional liposomes, is an interesting strategy to achieve enhanced internalization and accumulation of drugs in targeted cells. This was observed by the enhancement of cytotoxic and antiangiogenic effects in breast and prostate cell lines. / A nanotecnologia tem ganhado cada vez mais destaque em várias áreas da ciência, no sentido de desenvolver novos produtos que possam trazer benefícios em comparação com alternativas já existentes no mercado. Uma série de vantagens emergem da nanoencapsulação de fármacos quimioterápicos, principalmente, a possibilidade de diminuição da dose administrada através de estratégias de direcionamento. Dentre elas, podem ser citadas a vetorização passiva, relacionada ao aumento da permeabilidade vascular em regiões tumorais, e a vetorização ativa, que significa o uso de ligantes específicos, cujos receptores são superexpressos em células tumorais, e que ficam ancorados na superfície de nanoestruturas. A coencapsulação de fármacos antitumorais é altamente relevante, uma vez que permite a utilização de diferentes abordagens para eliminação de tumores e a sincronização da farmacocinética dos agentes coencapsulados. No caso deste trabalho, o objetivo foi a associação do efeito citotóxico do paclitaxel (PTX) ao efeito antiangiogênico do imatinibe (IB), encapsulados no mesmo lipossoma direcionado para o receptor folato, superexpresso em vários tumores sólidos. Foi desenvolvido e validado novo método analítico para quantificação simultânea do IB e do PTX. Os lipossomas foram desenvolvidos usando fosfatidilcolina de soja (PC) como lipídio estrutural, colesterol e DSPE-mPEG(2000), este último para conferir efeito de longa circulação. Foi desenvolvido método inédito de síntese da molécula DSPEPEG( 2000)-AF, âncora lipídica ligada ao ácido fólico destinada a biorreconhecimento. Essa molécula foi adicionada à formulação por pós-inserção. Os nanossistemas obtidos foram testados in vitro quanto à citotoxicidade e quanto à inibição da expressão gênica de VEGF em células de adenocarcinoma mamário (MCF7) e de próstata (PC3). O método analítico foi isocrático, com corrida de apenas 6,5 minutos, linear, seletivo, preciso e exato, com limite de quantificação 750 Ng/mL para o IB e 1000 Ng/mL para o PTX. Os lipossomas tiveram diâmetro médio próximo de 100 nm e baixo índice de polidispersão. Apenas após a inserção da âncora ligada ao ácido fólico as amostras ficaram mais polidispersas, devido ao tempo de agitação desse processo (24 h). O IB foi encapsulado na razão molar fármaco:lipídio 1:26 e o PTX na razão 1:27. As formulações liofilizadas, usando o crioprotetor trealose, mantiveram a estabilidade em termos de %EE após 60 dias de armazenamento. O método desenvolvido para síntese do componente DSPEPEG( 2000)-AF foi bem sucedido, o que pôde ser verificado através dos espectros de RMN, FT-IR e IES-EM, que evidenciam a formação de uma nova substância a partir dos reagentes, que tem as características químicas esperadas. O paclitaxel lipossomal foi mais citotóxico (p<0,05) para a linhagem MCF7, tanto em 24h como em 48h, em comparação com o fármaco livre, em todas as concentrações testadas. A formulação vetorizada com a âncora ligada ao ácido fólico, com IB e PTX coencapsulados, foi mais citotóxica (p<0,05) que a não vetorizada (LPIP) nas concentrações testadas, no tempo 24 h. Na linhagem PC3 a redução da viabilidade celular causada pela vetorização ativa, em comparação com o resultado da formulação não vetorizada, foi ainda maior (p<0,01) tanto em 24 como em 48h, nas concentrações 1 e 10 Ng/mL. Houve redução, nas linhagens MCF7 e PC3, da expressão gênica de VEGF, e também nesse caso o tratamento com a formulação vetorizada causou maior efeito em comparação com a não vetorizada (p<0,05). É razoável chegar-se à conclusão, através dos testes in vitro, de que o direcionamento de fármacos nanoencapsulados ao receptor folato, através do emprego de lipossomas multi-funcionais, é uma estratégia interessante no sentido de aumentar a quantidade de fármaco que entra nas células, o que pôde ser observado através do aumento dos efeitos citotóxico e anti-angiogênico em linhagens tumorais de mama e próstata.

Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2018-03-06T19:28:50Z No. of bitstreams: 2 Giovane_Zanin2014.pdf: 3169659 bytes, checksum: ca4852dea2558da8d3c74260c79fc413 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-06T19:28:50Z (GMT). No. of bitstreams: 2 Giovane_Zanin2014.pdf: 3169659 bytes, checksum: ca4852dea2558da8d3c74260c79fc413 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-09-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The polyvinyl acetate is a polymer used in the development of formulations for sustained release of drugs. Hyaluronic acid (HA) can interact with receptors on the plasma membrane, especially CD44 that overexpressed in tumor cells. This paper presents a pre-formulation study of isolated polyvinyl acetate films with the addition of HA to the application perspective in pharmaceutical dosage forms destined to modified drug release. The films were prepared using the solvent evaporation method and evaluated according to macroscopic and morphologic characteristics, thickness, Fourier transform infrared spectroscopy (FTIR), thermal analyses (thermogravimetry and differential scanning calorimetry), scanning electron microscopy, water vapor transmission, and swelling index. Addition of HA enabled the formation of isolated films, influencing transparency, flexibility, and thickness. FTIR spectra demonstrated that only physical mixing occurred. TG and DSC curves indicated that films are thermally stable up to 200C. Electron micrographs showed modifications in the polymer mesh structure in samples (85:15 and 80:20) previously immersed in simulated gastric fluid and more pronounced after immersion in simulated intestinal fluid. The HA concentration also influenced water vapor permeability and swelling increasing these indices. We propose that films with 95:05 and 90:10 compositions can be used for modified drug release, as they were similar to a reference film and maintained targeted delivery. / O acetato polivinílico (AcPV) é um polímero utilizado no desenvolvimento de formulações para liberação sustentadas de fármacos. O ácido hialurônico (AH) possui a habilidade de interagir com receptores nas membranas plasmáticas celulares, em especial o CD44 que esta super-expresso em células tumorais. O objetivo deste trabalho foi realizar um estudo de pré-formulação em filmes isolados de acetato polivinílico (AcPV) adicionados de AH na perspectiva de aplicação em formas farmacêuticas destinadas à liberação modificada de fármacos. Os filmes foram produzidos pelo método de evaporação do solvente e avaliados quanto as características macroscópicas e morfológicas, espessura, espectroscopia no infravermelho (FT-IR), análises térmicas (TG e DSC), microscopia eletrônica de varredura, transmissão de vapor de água e índice de intumescimento. Os resultados demonstraram que adição de AH permitiu a formação de filmes isolados adequados influenciando na transparência, flexibilidade e espessura. Espectro no FT-IR evidenciaram ocorrência apenas de mistura física entre os constituintes. As curvas TG e DSC indicaram que os filmes são termicamente estáveis até a temperatura de 200 ºC. Nas micrografias eletrônicas foi possível observar alterações na estrutural da malha polimérica nas composições 85:15 e 80:20 para as amostras previamente imersas em fluido de simulação gástrica, sendo ainda mais pronunciado após imersão em fluído de simulação intestinal. A concentração do AH também influenciou diretamente permeabilidade ao vapor de água e o intumescimento, aumentando estes índices. Na perspectiva de aplicação dos filmes avaliados, destacamos as composições 95:05 e 90:10, as quais sugerem maior potencial para aplicação em formas farmacêuticas para liberação modificada de fármacos uma vez que foram os mais semelhantes ao filme padrão e que mantiveram a possível capacidade de sítio alvo especificidade.

Os melanomas malignos em cães são uma das mais frequentes neoplasias diagnosticadas na cavidade oral. Infiltração local, recidiva (15-41%) e o alto potencial para metástases em linfonodos regionais (18-53%) e pulmões (23-27%) nos animais acometidos, conferem uma menor sobrevida (131-818 dias), ressaltando a necessidade e importância do estudo de novas terapias para o tratamento efetivo da doença. As uroquinases (UPA) e metaloproteinases (MMPs) são proteases superexpressas em uma variedade de células tumorais e raramente estão presentes em células fisiologicamente normais. A toxina do Bacillus anthracis é composta por três proteínas chamadas: fator letal (LF), fator de edema (EF) e antígeno protetor (PA). A toxina foi reengenheirada para a formação de dois tipos de PAs chamadas PAU2-R200A e PAL1-I207R, ativadas por UPA e MMPs da superficie das células tumorais, respectivamente, formando um complexo semelhante a um poro celular para permitir a internalização da LF. A citotoxicidade dessa associação reengenheirada PAU2-R200A, PAL1-I207R e LF ocorre quando a LF atinge o meio intracelular e causa a morte celular por interrupção da via de sinalização celular MAPkinase. O objetivo deste estudo é avaliar o potencial terapêutico da toxina reengenheirada do Bacillus anthracis, PAU2-R200A, PAL1-I207R e LF, dependentes de UPA e MMP, em melanomas orais de cães. Três etapas foram propostas para este estudo: o estudo in vitro da citotoxicidade de 5 linhagens de melanomas caninos submetidas à toxina reengenheirada, a avaliação da expressão de UPA e MMP em amostras parafinadas de melanoma oral canino e o tratamento intratumoral com a toxina modificada em cães com melanomas orais espontâneos. A linhagem GMGD2 foi a única que demonstrou sensibilidade à toxina estudada, apesar da concentração inibitória de 50% das células ter sido alta (IC50=4.964,16 mg/dl) em relação a linhagem controle HT29-RJ (IC50=179,47). As demais linhagens não demostraram redução da viabilidade celular com o aumento da concentração da toxina reengenheirada e não atingiram a IC50. Dentre as amostras de melanomas submetidos a imuno-histoquimica, 76,6% expressavam tanto uroquinases quanto metaloproteinases. Melanomas orais espontâneos de cães variando de 231,8 a 18601,6 mm3 em volume, sem evidências de metástases, foram tratados com as aplicações da toxina modificada por via intratumoral, previamente à excisão, realizada nos dias 07 ou 14 do tratamento. Dentre os animais estudados, todos apresentaram evolução favorável classificada como doença estável e resposta parcial. Somente um animal apresentou reação local. Nenhum dos pacientes apresentou efeito colateral sistêmico importante. Os resultados sugerem que existe potencial terapêutico da toxina reengenheirada do Bacillus anthracis sobre os melanomas bucais caninos e futuros ensaios clínicos são possíveis em cães e de extrema importância para o estudo mais aprofundado da toxina como nova terapia antineoplásica / Malignant melanomas in dogs are one of the most frequent malignancies diagnosed in the oral cavity. Local infiltration, recurrence (15-41%) and the high potential for regional lymph nodes metastases (18-53%) and lungs (23-27%) in the affected animals, confer a lower survival (131-818 days), emphasizing the necessity and importance of the study of new therapies for the effective treatment of the disease. Urokinase (UPA) and metalloproteinases (MMPs) are overexpressed proteases in a variety of tumor cells and are rarely present in normal physiological cells. Bacillus anthracis toxin is composed of three proteins called lethal factor (LF), edema factor (EF) and protective antigen (PA). The toxin was re-engineered for the formation of two types of PAs called PAU2-R200A and PAL1-I207R, activated by UPA and MMPs from the surface of tumor cells, respectively, forming a cell-like complex to allow the internalization of the LF. The cytotoxicity of this association PAU2-R200A, PAL1-I207R and LF occurs when LF reaches the intracellular environment and causes cell death by disruption of the MAPkinase cell signaling pathway. The objective of this study is to evaluate the therapeutic potential of UPA and MMP-dependent Bacillus anthracis toxin (PAU2- R200A, PAL1-I207R and LF) to treat oral melanomas in dogs. Three steps were proposed: cytotoxicity assay of 5 lineages of canine melanomas submitted to the reengineered toxin, immunohistochemistry study for UPA and MMP expression in paraffin samples of canine oral melanoma and intratumoral treatment with toxin in dogs with spontaneous oral melanomas. The lineage GMGD2 was the only one that showed sensitivity to the toxin studied, although 50% inhibitory concentration of the cells was high (IC50 = 4,964.16 mg / dl) in relation to the HT29-RJ control lineage (IC 50 = 179.47). Among the samples of melanomas submitted to immunohistochemistry, 76.6% expressed both urokinase and metalloproteinases. Spontaneous oral melanomas of dogs ranging volume from 231.8 to 18601.6 mm3 with no evidence of distant metastases, were treated with the applications of intratumoral re-engineered toxin prior to surgical excision. All of them has presented favorable evolution classified as stable disease and partial response. Only one animal had a local allergic reaction. None of the patients had a significant systemic side effects. The results suggest that there is a potential therapeutic effect of re-engineered anthrax toxin on canine melanomas and future clinical trials are possible in dogs and extremely important for further studies on the role of the B. anthracis toxin as a new antineoplastic agent

Avec 3000 nouveaux cas par an en France, le glioblastome multiforme (GBM) est la tumeur primitive du cerveau la plus fréquente. C’est aussi la plus agressive, l’espérance de vie moyenne des patients au moment du diagnostic ne dépassant guère 15 mois. Depuis l’étude de Stupp et collaborateurs en 2005, l’association radiothérapie – temozolomide est le traitement de référence en première ligne des glioblastomes nouvellement diagnostiqués. La protéine de la translocation (translocator protein, TSPO), connu aussi sous le nom de récepteur périphérique des benzodiazépines ou PBR, joue un rôle dans la biosynthèse des stéroïdes et le transport du cholestérol. L’interaction de la TSPO avec VDAC (Voltage-Dependant Anion Channel) dans les pores de transition de la perméabilité mitochondrial suggère également un rôle dans la régulation de l’homéostasie cellulaire et de l’apoptose. Certains travaux ont rapporté une surexpression de la TSPO dans des tumeurs cérébrales, suggérant que cette protéine pourrait représenter une cible moléculaire pour la thérapie du GBM. En particulier, l’Erucylphosphohomocholine (ErPC3, erufosine), dont l’activité antitumorale semble dépendre de la TSPO, a été capable d’induire l'apoptose in vitro dans des lignées de cellules de gliome résistantes à la chimiothérapie. Un radioligand de la TSPO pour l’imagerie par tomographie par émission de positons (TEP), le [18F]DPA-714, a été mis au point au CEA et validé dans différents modèles de neuroinflammation. Les hypothèses qui ont sous-tendu ce travail de thèse sont 1°) que la surexpression de la TSPO dans le GBM pouvait être mise en évidence par imagerie TEP au [18F]DPA-714 et 2°) que la manipulation pharmacologique de la TSPO, via les ligands spécifiques de cette protéine ou via l’ErPC3,pourrait induire l’apoptose dans les GBM. Les objectifs de la thèse étaient : 1°) d’évaluer l’expression de la TSPO dans un panel de cellules de gliomes murin et humain ; 2°) de caractériser, in vitro et in vivo, l’effet sur la survie cellulaire de lignées de GBM de l’administration de ligands de la TSPO [(et RO5-4864)] d’une part, ou de l’ErPC3 d’autre part ; 3°) de développer un modèle préclinique d’imagerie in vivo utilisant le [18F]DPA-714 pour suivre l’effet thérapeutique du ou des ligands sélectionné(s). Ce travail de thèse a démontré la faisabilité de l'imagerie TEP par [18F]DPA-714 pour détecter les gliomes 9L dans un modèle préclinique de rat et évaluer l’efficacité du traitement par ErPC3, ce qui pourrait constituer une nouvelle approche d’imagerie moléculaire du GBM. Il a permis de confirmer l'effet pro-apoptotique de l’ErPC3sur le gliome de rat in vitro et in vivo où une infiltration de la zone de la tumeur par les cellules microgliales/macrophages (CD11b-positives) et les astrocytes (GFAP-positives) chez les animaux traités à l’ErPC3 a pu être mise en évidence. Ces résultats ouvrent des perspectives intéressantes pour la recherche clinique dans le traitement des GBM. / In France alone, there are 3000 new cases of glioblastoma multiforme (GBM) per year and therefore GBM is the most common and aggressive form of the primary tumor in the central nervous system (CNS). The clinical prognosis for glioblastoma patients is extremely poor with a median survival period that rarely exceeds 15 months post-diagnosis. Since the study performed by Stupp and colleagues in 2005, the standard treatment for newly diagnosed glioblastoma consists of surgical removal of the tumor, followed by radiotherapy and concomitant chemotherapy with temozolomide. The 18 kDa Translocator Protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR) is a mitochondrial membrane protein known to be implicated in cholesterol transport, protein import, transport of porphyrin, cell proliferation and apoptosis through its interaction with VDAC (Voltage-Dependent Anion Channel) in the mitochondrial permeability transition pore (PTPM). Previous studies have reported overexpression of TSPO in brain tumors, suggesting that this protein may represent a molecular target for the therapy of GBM. In particular, Erucylphosphohomocholine (ErPC3, erufosine), an alkylphosphocholine, seems to be a promising agent in the treatment of glioblastoma. Previous studies have reported its ability to induce apoptosisin otherwise highly apoptosis resistant glioma cell lines and ErPC3 induced apoptosis seems to require the presence TSPO. [18F]DPA-714, a new TSPO radioligand for positron emission tomography (PET) imaging, was developed at the CEA and validated in different models of neuroinflammation. The hypotheses underlying this thesis are: 1) that the overexpression of TSPO in GBM can be detected by PET imaging using [18F]DPA-714 and 2) that the targeting of TSPO, via specific ligands or via ErPC3, can induce apoptosis in GBM. The objectives of the thesis were: 1) to evaluate the expression of TSPO in a panel of rodent and human glioma cell lines and 2) to characterize, in vitro and in vivo, the anti-neoplastic effect of TSPO ligands (PK11195 and RO5-4864) or ErPC3 in glioma cell lines as well as 3) to develop a preclinical model for in vivo PET imaging using [18F]DPA-714 to monitor treatment efficacy of selected ligands. In this thesis, we demonstrated the feasibility of using PET imaging with [18F]DPA-714 to characterize 9L glioma in an orthotopic rat model and to evaluate the effect of ErPC3 treatment, which could provide a new approach to molecular imaging of GBM. We confirmed the pro-apoptotic effect of ErPC3 in the rat 9L glioma cells in vitro and in vivo, and found an infiltration of microglia/macrophages (CD11b-positive) and astrocytes (GFAP-positive) in the tumor area of animals treated with ErPC3. These results open interesting perspectives for clinical research in the treatment of GBM.

Le cancer de la prostate est le cancer le plus fréquent chez les hommes et la capacité des tumeurs à développer une résistance face aux thérapies anti-androgéniques vient souvent compromettre le pronostic des patients. Le développement de nouvelles approches thérapeutiques afin de circonvenir à la progression de ces tumeurs représente un besoin important la gestion de ce type de cancer. Plusieurs démonstrations récentes établissent l’implication de la famille des proprotéines convertases dans la progression tumorale. Ces enzymes ont pour fonctions biologiques de cliver une variété de précurseurs protéiques jouant des rôles importants dans la tumorigénèse. Dans le cancer de la prostate, la proprotéine convertase PACE4 est fortement surexprimée dans les cellules cancéreuses et joue un rôle dans la prolifération et la capacité à former des tumeurs, ce qui en fait une cible thérapeutique d’intérêt. En ce sens, des inhibiteurs peptidomimétiques ont été développés dans l’optique de la thérapie ciblée contre la PACE4. Toutefois, dans le but de développer une approche thérapeutique optimale, il convient néanmoins de comprendre le niveau de redondance fonctionnelle entre les différents membres de la famille des convertases, qui sont connus pour partager plusieurs de leurs substrats, ainsi que les mécanismes moléculaires régissant l’activité de la PACE4 et de ses substrats sous-jacents. L’utilisation d’une approche de répression génique stable envers les différentes convertases a permis de mettre en lumière les fonctions uniques de la PACE4 dans la progression tumorale. De plus, grâce à une approche de protéomique comparative, le premier substrat de la PACE4 dans le cancer de la prostate; le growth differenciation factor 15, a été découvert. Ce substrat permet de commencer à dresser l’implication de PACE4 dans le paysage moléculaire du cancer de la prostate. Grâce à des modalités d’imagerie moléculaire, l’emploi de versions radiomarquées des inhibiteurs peptidiques a également permis de démontrer que les composés s’accumulent dans les cellules cancéreuses en fonction des niveaux de PACE4 présents, et ce, tant in cellulo qu’in vivo. Ces données suggèrent un potentiel pour le développement d’un examen théranostique pour prédire la réponse tumorale à la pharmacothérapie anti-PACE4. Finalement, l’analyse de l’épissage alternatif de l’ARNm de PACE4 a permis l’élucidation des caractéristiques biochimiques et des fonctions spécifiques d’une nouvelle isoforme; la PACE4-altCT, qui est exprimée chez les cellules cancéreuses de la prostate, mais aussi d’autres types de cancer. Cette découverte a permis de redéfinir le modèle de travail en intégrant le concept de la rétention intracellulaire de cette isoforme qui semble médier la plupart de l’activité pro-proliférative reliée à l’activité PACE4, ce qui en fait la cible pharmacologique principale des inhibiteurs peptidiques dans le cancer de la prostate, mais aussi un biomarqueur potentiel. / Abstract: Prostate cancer is the most common cancer among men. The capabilities of tumors to adapt and overcome antiandrogenic therapy is persistently worsening patient’s prognostic and the development of novel therapeutic approaches to circumvent tumor progression therefore represents an unmet need. Many reports now demonstrate the implication of the enzymes from the proprotein convertase family in the progression of tumor from many cancer types. These enzymes are responsible for the processing of various protein precursors playing important roles in tumorigenesis. In prostate cancer, the proprotein convertase PACE4 is strongly overexpressed in cancer cells and plays a role in cell proliferation and tumor formation thus making a strong case for its use as a pharmacological target. For this reason, PACE4 peptidomimetic inhibitors were generated to develop PACE4-targeted therapies. However, to develop an optimal therapeutic approach regarding the inhibition of this enzyme, a complete understanding of the level of functional redundancy between the different convertases in prostate cancer is needed. Moreover, understanding the molecular mechanisms both upstream and downstream of PACE4 in prostate cancer cells would allow a better understanding of the considerations underneath such a therapeutic strategy. Using a stable gene silencing approach to knockdown all co-expressed member of the convertase family in prostate cancer cells, the roles of PACE4 in tumor progression were found to be unique and non-redundant among the other family member. Through a comparative proteomic approach, the first PACE4-specific substrate in prostate cancer; growth and differentiation factor 15, was identified. With this substrate growth factor, it is now possible to initiate the dissection of PACE4 biochemical functions in the prostate cancer molecular landscape. Using a radiolabelled version of the PACE4 peptide inhibitors, it was possible to demonstrate using molecular imaging that when applied in cellulo and in vivo, the compound is uptaken by cancer cells as well as by tissues according to their PACE4 expression levels. These data suggest that such PACE4 molecular imaging with pharmacological inhibitor could be developed as a theranostic assay to predict which tumor could be treated by PACE4-targetted therapy. Lastly, PACE4 mRNA alternative splicing analysis permitted the discovery of a new PACE4 isoform; named PACE4-altCT, which is strongly overexpressed by prostate cancer cells as well as other cancer types. As this isoform displays specific biochemical features and functions, notably being intracellularly retained and mediating most of the PACE4-associated cell growth capabilities, this discovery further redefined our working model, pointing to PACE4-altCT as the pharmacological target of inhibitory peptides in prostate cancer as well as a potential biomarker.

No description available.

The thesis argues that non-proliferation sanctions are effective primarily by their coercive effect, that is their power to change the target’s cost/benefit ratios. It does so by contrasting and comparing two key works in sanctions literature, authored by David Baldwin and the Targeted Sanctions Consortium respectively. In the case of the UN sanctions regime against the Democratic People’s Republic of Korea (DPRK), it concludes that the reason why no sufficient coercive effect has been apparent, is due to the lack of costs shouldered by the actors who have implemented the sanctions, as this reflects an apparent lack of commitment. This in turn does not sufficiently increase the possible cost of the DPRK, in continuing its nuclear weapons program. Therefore it is not incentivized to cancel its program.

Internetövervakning har under senaste tiden blivit ett aktuellt ämne i media. Det rapporteras bland annat om att företag som samlar in information om privatpersoner. Datan som samlas in kan innehålla information om användares beteende på internet såsom besökta sidor, sökhistorik, aktivitet på sociala medier med mera. Men hur mycket av detta vet en vanlig användare om? Uppsatsens syfte är att undersöka hur medvetna privatpersoner är om internetövervakning som bedrivs av företag och den datainsamling som den bygger på. Vad vet egentligen användarna om vad som samlas in, i vilket syfte, samt hur det samlas in? En studie utfördes bestående av intervjuer och enkäter som undersökte hur pass kunniga och upplysta privatpersoner var inom ämnet. Det undersöks också om användare aktivt försöker motverka detta. Därefter diskuteras vad kunskapsnivån kan bero på och vad de gör för att motverka datainsamling. Detta kopplas och jämförs mot tidigare forskning inom området. / Internet surveillance has recently become a hot topic in the media. It is reported among other things that companies collect information about individuals. The data collected may include information about the user's behavior on the internet such as pages visited, search history, activity on social media and more. But how much of this does a regular user know? The purpose of this study is to investigate how aware individuals are of internet surveillance conducted by companies and the data collection which it is based on. What do the users really know about what is collected, for what purpose, and how it is collected? A study was conducted consisting of interviews and questionnaires that examined how knowledge and education individuals have within the subject. It is also examined whether users are actively trying to counteract this. Thereafter it is discussed what this level of knowledge may depend on and what they are doing to counter data collection. This is linked and compared to previous research in the area.

Le carcinome hépatocellulaire est un grand problème de santé publique et la troisième de mortalité lié au cancer dans le monde. Il a été démontré qu'au sein des tumeurs se trouve un petite population des cellules cancéreuses avec des propriétés de cellules souches cancéreuses. Elles sont responsables de l'initiation des tumeurs ainsi que de la récidive post-traitement et résistance aux thérapies. Peu de choses sont connues par rapport à la biologie de ces cellules mais l'identification des facteurs favorisant leur existence pourrait conduire vers des nouvelles pistes thérapeutiques.Nous avons trouvé que le facteurs de transcription p73 est surexprimé chez les patients dans les tumeurs du carcinome hépatocellulaire sous forme de deux types d'isoformes, les isoformes complets et les isoformes tronqués. Les isoformes complets sont des suppresseurs de tumeurs et corrèlent avec un meilleur taux de survie alors que les isoformes tronqués agissent comme dominants négatifs de ces premiers et favorisent la récidive post-chirurgie.Les résultats in vitro ont montré que les isoformes tronqués de p73 sont surexprimés dans les cellules souches cancéreuses du carcinome hépatocellulaire et favorisent leur emergence / Hepatocellular carcinoma (HCC) is a major public health problem, being the second most lethal cancer with an increasing incidence around the world. The only approved systemic drug is the multikinase inhibitor Sorafenib, which prolongs patients’ survival by only three months. HCC is refractory to known chemotherapeutic drugs and more than 50% of patients relapse after surgical tumor removal. These phenomena are thought to be due to the existence of a population of poorly differentiated cancer cells, largely known as liver cancer stem cells (CSCs). Recent studies revealed that CSCs activate similar pathways as normal stem cells. They are therefore highly resistant to therapies and are thought to be capable of self-renewal and generation of tumor’s heterogeneous cell mass. The understanding of mechanisms proper to liver CSCs should allow the development of innovative drugs with original mechanism of action against liver CSC, likely to improve patients’ outcome. However, the development of new therapies against HCC is penalized by the limited number of experimental models.According to these current challenges in the field of HCC research, my PhD thesis project covers three main axes: Development of novel models of disease (IMODI consortium)The Innovative Models of Disease (IMODI) consortium is mainly dedicated to the development of innovative experimental models for 7 different types of cancer. Our participation to the project concerned 3 main objectives i) development of HCC patient-derived xenografts ii) development of new HCC cell lines and iii) set up a cryoconservation method of primary human hepatocytes (PHHs) in the aim to employ them in humanizing murine livers. 30 patients planned for HCC tumor resection were recruited and their clinicopathological data were collected. Fresh tumor specimens were subcutaneously xenografted in immune-deficient mice and dissociated for in-vitro tumor cell culture. One tumor led to the development of a moderately differentiated HCC PDX model, as confirmed by histological characterization. Several studies showed the importance of PDX models in drug discovery as they recapitulate the drug-sensitivity patterns seen in patients from which they derive but very few models have been described in the literature for HCC. In vitro, primary HCC cells could be maintained in culture for a limited period of time, in average 30 days. No HCC cell lines developed due to cells entering replicative senescence, as previously described