Made available in DSpace on 2014-08-20T13:32:48Z (GMT). No. of bitstreams: 1 dissertacao_karine_begnini.pdf: 1622668 bytes, checksum: 238f06c82a5dce8f22542c15f37944f4 (MD5) Previous issue date: 2012-02-15 / Bacillus Calmette-Guerin (BCG) is one of the great success stories of immunotherapy as a treatment for superficial urothelial carcinoma of the bladder. The high incidence of local side effects and presence of non-responder diseases has led to efforts to improve the therapeutic vaccine. Hence, we proposed that an auxotrophic recombinant BCG strain overexpressing Ag85B (BCG ΔleuD/Ag85B), could enhance cytotoxicity to the human bladder carcinoma cell line (5637). This rBCG was generated by incorporating an expression plasmid encoding the mycobacterial antigen Ag85B into the BCG ΔleuD strain. The inhibitory effect of BCG ΔleuD/Ag85B in 5637 cells was determined by the MTT method, morphology observation and the LIVE/DEAD assay. Gene expression profiles for apoptotic genes, cell cycle-related genes and oxidative stress-related genes were investigated by qRT-PCR. Bax, bcl-2 and p53 induction by BCG ΔleuD/Ag85B treatment were evaluated by Western blotting. BCG ΔleuD/Ag85B revealed a superior cytotoxicity effect than the strains used as controls in this study. The results demonstrated that the expression level of pro-apoptotic and cell cycle-related genes increased after BCG ΔleuD/Ag85B treatment, whereas mRNA levels of antiapoptotic genes decreased. Interestingly, BCG ΔleuD/Ag85B also increased the mRNA level of antioxidant enzymes in bladder cancer cell line. Bax and p53 protein levels were increased by BCG ΔleuD/Ag85B treatment. In conclusion, these results suggested that BCG ΔleuD/Ag85B enhanced cytotoxicity on superficial bladder cancer cells in vitro. The therapeutic model using rBCG may have potential for future clinical application in the treatment of bladder cancer. / O Bacilo Calmette-Guérin (BCG) constitui uma das grandes histórias de sucesso da imunoterapia como tratamento para carcinoma superficial da bexiga. Porém, a alta incidência de efeitos colaterais locais e a ocorrência de tumores resistentes ao tratamento têm impulsionado estudos visando melhorias da vacina terapêutica. Neste trabalho, propusemos que uma cepa auxotrófica de BCG superexpressando o antígeno Ag85B (BCG ΔleuD/Ag85B), é capaz de aumentar a citotoxicidade na linhagem celular humana de carcinoma superficial de bexiga (5637). A cepa de BCG recombinante foi gerada através da incorporação da sequencia do antígeno Ag85B em um plasmídeo de expressão micobacteriano na cepa de BCG ΔleuD. O efeito inibitório do BCGΔleuD/Ag85B em células 5637 foi determinada através das técnicas colorimétricas MTT e LIVE/DEAD, além de observação morfológica. Os perfis de expressão gênica para genes apoptóticos, genes relacionados ao ciclo celular e genes de estresse oxidativo foram avaliados por qRT-PCR. Os níveis protéicos de bax, bcl-2 e p53 foram avaliados por western blot. O BCG ΔleuD/Ag85B revelou citotoxicidade superior às cepas utilizadas como controle neste estudo. Os resultados obtidos demonstram níveis superiores de expressão de genes pró-apoptóticos e de genes relacionados com o ciclo celular após tratamento com BCG ΔleuD/Ag85B. Níveis inferiores de mRNA de genes antiapoptóticos foram detectados após o mesmo tratamento. Ainda, o tratamento com BCG ΔleuD/Ag85B também elevou os níveis de mRNA de enzimas antioxidantes em linhagem de células de câncer superficial de bexiga. As proteínas Bax e p53 mostraram-se elevadas após tratamento com BCG ΔleuD/Ag85B. Em conclusão, estes resultados sugerem que a cepa de BCG superexpressando Ag85B é capaz de aumentar a citotoxicidade sobre as células de câncer superficial de bexiga in vitro. Este modelo terapêutico usando BCG recombinante possui potencial para uma futura aplicação clínica em tratamento de câncer de bexiga.

Actuellement le criblage en vue de la recherche de nouveaux agents antitumoraux se base principalement sur la qualité cytotoxique d’une molécule. Le principal défaut de cette approche est qu’aucune sélection n’est faite sur le mode d’action du médicament. L’objectif de ce travail est la mise au point d’une méthode permettant un classement rapide et objectif du mode d’action de molécules à visée thérapeutique par spectroscopie infrarouge.<p>La spectroscopie infrarouge est une technique d’absorption de la lumière fournit la signature chimique d’un échantillon. L’excellente qualité du signal rend possible son utilisation comme outil discriminant. En outre, cette technique d’analyse se démarque des autres par son caractère non destructif et la rapidité d’acquisition des données. Elle se révèlerait donc une méthode de choix pour effectuer du criblage de molécules en vue de la recherche de nouveaux agents thérapeutiques.<p><p>Dans un premier temps nous avons voulu évaluer la possibilité d’utiliser la spectroscopie infrarouge pour isoler la signature spectrale du mode d’action induit par des concentrations sub-létales de ouabaïne, un composé de la famille des cardénolides, sur une lignée tumorale de prostate. Nous avons montré que cette signature évolue au cours du temps et peut-être corrélée aux données biologiques décrites dans la littérature. Nous avons également mis en évidence pour la première fois une modification de la composition lipidique de la cellule. Cette altération a été caractérisée au cours du temps par spectrométrie de masse.<p>Nous avons ensuite voulu définir les limites de la méthode. La littérature souligne la diversité des modes d’action que peut induire un agent thérapeutique selon sa concentration. Nous avons montré que cette diversité se reflète sur le spectre infrarouge de cellules tumorales traitées à la ouabaïne en distinguant au moins deux modes d’action distincts, dépendant de la concentration en ouabaïne. Par ailleurs, nous avons montré que la confluence pouvait modifier significativement le spectre infrarouge d’une cellule. Neanmoins cette signature est unique et orthogonale à celle induite par la ouabaïne.<p>Finalement, nous avons évalué le potentiel de la spectroscopie infrarouge à distinguer des modes d’action induits par des molécules à la structure chimique proche. Nous avons montré qu’il était possible de caractériser spécifiquement chacun des modes d’action. D’autre part nous avons mis en évidence que les modes d’action de molécules issues d’une même classe d’agent thérapeutique conduisaient à des signatures spectrales similaires. Cette partie du travail souligne la possibilité d’utilisation de la spectroscopie infrarouge pour un classement objectif, uniquement basé sur leur mode d’action d’agents thérapeutiques potentiels.<p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished

Células tumorais desenvolvem diversas estratégias para escapar da identificação e eliminação pelo sistema imune. Dessa forma, a investigação dos mecanismos envolvidos na comunicação celular no microambiente tumoral e na desregulação local do sistema imune é crítica para uma melhor compreensão da progressão da doença e para o desenvolvimento de alternativas terapêuticas mais eficazes. Nós aqui demonstramos que SIGIRR/IL-1R8, um importante regulador negativo de receptores de Interleucina-1 (ILRs) e receptores do tipo Toll (TLRs), apresenta expressão aumentada em uma linhagem celular epitelial mamária transformada pela superexpressão do oncogene HER2 e em tumores primários de mama, e promove o crescimento tumoral e metástase através da modulação da inflamação associada ao câncer e da atenuação da resposta imune antitumoral. Observamos que IL-1R8 tem sua expressão correlacionada com HER2 em tecidos mamários e sua alta expressão é fator de pior prognóstico em câncer de mama de baixo grau. Notavelmente, níveis aumentados de IL-1R8 foram observados especialmente nos subtipos HER2+ e Luminais de tumores de mama, e sua expressão aumentada em células epiteliais de mama transformadas por HER2 diminui a ativação da via de NF-&#954;B e a expressão de diferentes citocinas pro-inflamatórias (IL-6, IL-8, TNF, CSF2, CSF3 e IFN-&#946;1). Meio condicionado de células transformadas por HER2, mas não de variantes celulares com o gene IL-1R8 silenciado, induz a polarização de macrófagos para o fenótipo M2 e inibe a ativação de células NK. Em um modelo murino transgênico de tumorigênese espontânea mediada por HER2, MMTV-neu, verificamos que a deficiência de IL-1R8 (IL-1R8-/-neu) retardou o aparecimento de tumores e reduziu a incidência, a carga tumoral e a disseminação metastática. Contudo, não foram observadas diferenças significativas no crescimento tumoral quando animais IL-1R8-/-neu receberam medula óssea de animais IL-1R8+/+, confirmando um papel importante da expressão de IL-1R8 em células não hematopoiéticas na tumorigênese da mama. Tumores IL-1R8+/+neu apresentaram maiores níveis de citocinas pró-inflamatórias como IL-1&#946; e VEGF, e menores níveis da citocina imunomodulatória IFN-&#947;. Além disso, tumores que expressavam IL-1R8 apresentaram menor infiltrado de células NK maduras, células dendríticas (DCs) e linfócitos T-CD8+ e um maior infiltrado de macrófagos M2 e linfócitos T-CD4+. Coletivamente, esses resultados indicam que a expressão de IL-1R8 em tumores de mama pode representar um novo mecanismo de escape da resposta imune e suportam IL-1R8 como potencial alvo terapêutico. / Tumor cells develop numerous strategies to fine-tune inflammation and avoid detection and eradication by the immune system. Identification of new players that regulate the cellular crosstalk within the tumor microenvironment and promote local immune dysregulation is critical to understand disease progression and to improve therapeutic strategies. Here, we demonstrate that SIGIRR/IL-1R8, a negative regulator of IL-1R and TLRs, is up-regulated in a HER2-transformed epithelial mammary cell line and in primary breast tumors and promotes tumor growth and metastasis by modulating cancer-related inflammation and impairing anti-tumor immunity. IL-1R8 expression is correlated with HER2 in mammary tissue, and higher tumor IL-1R8 expression is a poor prognostic factor in lower grade breast tumors. Notably, higher levels of IL-1R8 expression were observed in HER2+ and Luminal breast tumor subtypes and IL-1R8 up-regulation in HER2-transformed mammary epithelial cells inhibited NF-&#954;B activation and the expression of pro-inflammatory cytokines (IL-6, IL-8, TNF&#945;, CSF2, CSF3, IFN-&#946;1). Conditioned medium from HER2-transformed cells, but not from IL-1R8 knockdown variants, induced M2-macrophage polarization and inhibited natural-killer (NK) cell activation. IL-1R8 deficiency in a transgenic mouse model of breast tumorigenesis (MMTV-neu) significantly delayed tumor onset and reduced tumor incidence, burden and metastasis. No significant differences in tumor growth were observed when IL-1R8-/-neu mice were transplanted with bone marrow from IL-1R8+/+ animals, confirming an important role for IL-1R8 expression in non-hematopoietic cells during breast tumorigenesis. IL-1R8+/+neu mammary tumors presented higher levels of pro-inflammatory cytokines such as IL-1&#946; and VEGF, but lower levels of IFN-&#947;. Besides, a lower infiltrate of mature NK cells, dendritic cells (DCs) and CD8+ T cells but higher infiltrate of M2-macrophages and CD4+ T cells were present in IL-1R8 expressing tumors. Collectively, our results support IL-1R8 expression as a novel tumor immune escape mechanism in breast cancer and putative target for immunotherapy.

L’immunothérapie basée sur le transfert de lymphocytes T (LT) spécifiques de la tumeur est une approche prometteuse contre le cancer. Pour activer et amplifier de tels LT, principale étape limitante de cette approche, des cellules présentatrices d’antigène artificielles (CPAA) ont été développées au laboratoire. Ces CPAA ont été construites à partir de fibroblastes murins NIH/3T3 transduits à l’aide de vecteurs gammarétroviraux afin d’exprimer les principaux éléments nécessaires à l’activation de LT humains. Ces CPAA nous permettent d’obtenir des LT mémoires souches (TSCM : CD95+CD45RA+CD62L+CCR7+), LT très peu différenciés récemment identifiés chez l’homme. Ces TSCM ont été décrits comme étant du plus grand intérêt pour l’immunothérapie en raison de leur capacité d’auto-renouvellement et de leur faculté à se différencier en LT effecteursefficaces. Pour optimiser l’amplification de TSCM spécifiques, nous avons notamment étudié les effets sur les LT de l’expression de différentes molécules de costimulation par nos CPAA (CD80, CD70 et 4-1BBL). Les protéines MART-1 et MELOE-1, surexprimées dans les mélanomes, ont été utilisées comme antigènes modèles pour ces travaux. Les CPAA CD80+CD70+ et CD80+CD70+4-1BBL+ sont les plus prometteuses pour maintenir le phénotype des TSCM. Une étude exhaustive des CPAA CD80+CD70+ a montré que nous pouvions obtenir un plus grand nombre de TSCM fonctionnels spécifiques de MART-1 et de MELOE-1 de manière reproductible avec ces CPAA. Dans une seconde étude, nous avons pu montrer que les CPAA CD80+CD70+4-1BBL+ permettaient d’obtenir le plus grand nombre de LT spécifiques fonctionnels et très peu différenciés après purification et restimulation de LT spécifiques stimulés une première fois par les CPAA CD80+CD70+. Ces travaux devraient nous permettre, après le développement d’un modèle murin, de proposer de nouvelles stratégies d’immunothérapie basées sur l’obtention grâce à nos CPAA optimisées de LT spécifiques anti-tumoraux capables d’assurer une protection à long terme aux patients. / Immunotherapy based on the transfer of tumor-specific T lymphocytes (TLs) is a promising approach against cancer. To activate and amplify such TLs, main limiting step of this approach, artificial antigen presenting cells (AAPCs) have been developed in the laboratory. These AAPCs have been constructed from NIH/3T3 murine fibroblasts transduced with gammaretroviral vectors to express the principal elements required to activate human TLs. With these AAPCs, we can obtain anti-tumor stem cell memory TLs (TSCM: CD95+CD45RA+CD62L+CCR7+), which are very limitedly differentiated TLs recently identified in humans. These TLs have been recently described as cells of great interest for immunotherapy because of their self-renewal capacity and their ability to differentiate into effective effector TLs. To improve the amplification of specific TSCM, we notably studied the effects on TLs of the expression of different co-stimulatory molecules by our AAPCs (CD80, CD70 and 4-1BBL). MART-1 and MELOE-1, proteins that are overexpressed in melanoma, were used as model antigens in this work. CD80+CD70+ and CD80+CD70+4-1BBL+ AAPCs appear to be the most promising ones for maintaining a TSCM phenotype. An exhaustive study of CD80+CD70+ AAPCs showed that we could reproducibly get greater numbers of MART-1- and MELOE-1-specific functional TSCM with these AAPCs. In another study, we have shown that CD80+CD70+4-1BBL+ AAPCs enabled us to get the greatest number of functional and very limitedly differentiated specific TLs after purification and restimulation of specific TLs stimulated first with CD80+CD70+ AAPCs. This work should allow us, after the development of a murine model, to propose new immunotherapy strategies based on the possibility of obtaining with our optimized AAPCs anti-tumor specific TLs capable of ensuring patient long term protection.

No description available.

As fosfolipases A2 (PLA2s) catalisam a hidrólise de ácidos graxos na posição sn-2 das membranas fosfolipídicas e liberam, como subprodutos, ácidos graxos livres. As PLA2s do grupo IIA são encontradas em peçonhas de serpentes da família Viperidae e desempenham diversas atividades apresentando potencial miotóxico, neurotóxico, hemolítico, edematogênico, citotóxico, hipotensivo, anticoagulante, inibição/ativação da agregação plaquetária, bactericida e pró-inflamatório. Esse trabalho teve como objetivo o isolamento e a caracterização funcional de uma PLA2 isolada da peçonha de Bothrops jararaca. Para a purificação dessa proteína, denominada BJ-PLA2-I, foram necessários três passos cromatográficos consecutivos: cromatografia de exclusão molecular em Sephacryl S-200, cromatografia de troca iônica em Source TM 15Q/50mL e cromatografia de troca iônica em MonoQ TM 5/50 GL. A BJ-PLA2-I apresentou elevado grau de pureza por SDS-PAGE e por cromatografia de fase reversa C18, em HPLC. Apresentou ainda, características ácidas, com pI em torno de 4,4 e teve a sua massa molecular determinada por dois métodos, obtendo-se valores bem próximos de 14,8 kDa (SDS-PAGE) e 14,2 kDa (MALDI-TOF). Esse fato é comum considerando que a espectrometria de massas é um método mais preciso e determina de maneira mais exata a massa molecular. O sequenciamento N-terminal da BJ-PLA2-I resultou em 60 resíduos de aminoácidos. O alinhamento múltiplo com outras fosfolipases A2 de serpentes do mesmo gênero mostrou similaridade entre elas, mostrando identidade de 100% com a BJ-PLA2, fosfolipase A2 Asp-49, também isolada da Bothrops jararaca. Esse dado levanta a hipótese de que a BJ-PLA2-I purificada neste trabalho e a BJ-PLA2 se tratam da mesma proteína, entretanto essa hipótese só poderá ser confirmada quando a sequência completa da BJ-PLA2-I for obtida. Outros dados encontrados neste trabalho reforçam essa hipótese, isso porque, avaliando a atividade fosfolipásica, o efeito sobre as plaquetas e o pI, tanto a BJ-PLA2-I quanto a BJ-PLA2 apresentaram características semelhantes. A BJ-PLA2-I, sendo uma Asp-49, mostrou alta atividade catalítica e efeito inibidor da agregação plaquetária induzida por ADP (20,5 ?g/mL inibiu 50 % da agregação plaquetária). Ela também foi capaz de induzir a migração leucocitária após a administração de diferentes concentrações (5, 10 e 20 ?g/mL) da BJ-PLA2-I. Esse dado também foi encontrado no ensaio em que a concentração de 10 ?g/mL foi fixada e variou-se o tempo de 2, 4 e 24 horas, observando-se principalmente a migração de neutrófilos. Além disso, verificou-se a liberação das citocinas IL-6 e IL-1?, de proteínas totais e de prostaglandina E2 na reação inflamatória induzida pela BJ-PLA2-I. No entanto, não foi observado a produção de TNF-?, IL-10 e leucotrieno B4. A BJ-PLA2-I caracterizou-se como uma PLA2 pró-inflamatória, produzindo inflamação local aguda. A BJ-PLA2-I foi avaliada quanto ao seu potencial antitumoral em três linhagens celulares distintas (PBMC, HL-60 e HepG2). Observou-se que a enzima em questão possui baixo potencial antitumoral para a linhagem HL-60, reduzindo o número de células tumorais em apenas cerca de 20% nas concentrações testadas. Verificou-se pequena alteração na viabilidade celular das células de PMBC, nas maiores concentrações testadas (160 e 80 ?g/mL) e, na linhagem HepG2 não foi encontrada nenhuma alteração. Concluindo, as informações adquiridas neste trabalho são de suma importância para a melhor compreensão dos mecanismos envolvidos nas atividades biológicas desempenhadas pelas PLA2s. Além disso, a BJ-PLA2-I pode servir como modelo molecular para a formulação de fármacos mais eficazes a serem utilizados no tratamento de várias doenças. / Phospholipases A2 (PLA2s) catalyze the hydrolysis of fatty acids in the sn-2 position of membrane phospholipids, releasing free fatty acids as by-products. PLA2s of group IIA are found in snake venoms of the Viperidae family and perform various activities, including myotoxic, neurotoxic, hemolytic, edematogenic, cytotoxic, hypotensive, anticoagulant, inhibition/activation of platelet aggregation, bactericidal and proinflammatory effects. This work aimed at the isolation and functional characterization of a PLA2 isolated from Bothrops jararaca venom. For the purification of this protein, called BJ-PLA2-I, three consecutive chromatographic steps were used (size exclusion chromatography on Sephacryl S-200, ion exchange chromatography on Source 15Q/50 mL, ion exchange chromatography on MonoQ 5/50 GL). Confirmation of the purity of BJ-PLA2-I was evaluated by SDS-PAGE and reverse phase HPLC using a C18 column. BJ-PLA2-I has acidic characteristics, with pI around 4.4, and its molecular mass was determined by two methods, obtaining values close to 14.8 kDa (SDS-PAGE) and 14.2 kDa (MALDI-TOF). The N-terminal sequencing of BJ-PLA2-I resulted in 60 amino acid residues. Multiple alignment with other phospholipases A2 of snakes of the same genus showed high similarity between them, showing 100% identity with BJ-PLA2, an Asp-49 phospholipase A2 previously isolated from Bothrops jararaca venom. This finding raises the possibility that the PLA2 purified in this work is the same protein previously described (BJ-PLA2), however, this assumption can only be confirmed when the complete sequence of BJ-PLA2-I is obtained. Other data obtained in this study support this hypothesis, considering that the phospholipase activity, the effect on platelets and pI of both BJ-PLA2-I and BJ-PLA2 showed to be similar. BJ-PLA2-I, being an Asp-49 PLA2, showed high catalytic activity and inhibitory effect on the platelet aggregation induced by ADP (20.5 ?g/mL inhibited 50% of the platelet aggregation). It was also able to induce leukocyte migration after the administration of different concentrations (5, 10 and 20 ?g/mL) of BJ-PLA2-I. This fact was also found when the concentration of 10 ?g/mL was fixed and response times were varied (2, 4 and 24 hours), observing especially neutrophil migration. Furthermore, there was a release of IL-6 and IL-1?, total proteins and prostaglandin E2 in the inflammatory reaction induced by BJ-PLA2-I, however, the production of TNF-?, IL-10 and leukotriene B4 was not observed. BJ-PLA2-I was characterized as a proinflammatory PLA2 producing acute local inflammation. BJ-PLA2-I was evaluated for its antitumor potential on three different cell lines (PBMC, HL-60 and HepG2). It was observed that this enzyme showed a low antitumor potential on HL-60 tumor cell line, reducing the number of tumor cells in only about 20% at the concentrations tested. There was little change in cell viability of PBMC cells in the higher concentrations tested (80 and 160 ?g/mL), but no change was found on HepG2 tumor cell line. In conclusion, the information obtained in this work are of utmost importance for better understanding the mechanisms involved in the biological activities induced by PLA2s. Furthermore, BJ-PLA2-I may serve as a molecular model for the formulation of more effective drugs to be used in the treatment of various diseases.

O uso da LDE como veículo para quimioterápicos tem mostrado ser uma boa estratégia para aumentar a eficácia terapêutica dos mesmos. Nesse estudo, a LDE foi empregada como veículo para um derivado lipofílico do metotrexato (MTX), o di-dodecil metotrexato, que foi obtido com rendimento elevado através de reação de esterificação do MTX. O aumento na lipofilicidade do derivado possibilitou incorporação na LDE com rendimento e estabilidade elevados. O IC50 de LDE-di-dodecil MTX foi cerca de 100 vezes menor em relação ao MTX comercial, sua captação celular mais elevada nas linhagens leucêmicas estudadas e sua toxicidade animal reduzida, mostrando que a LDE é um veículo promissor para este fármaco. / The use of LDE as vehicle to drugs is a great strategy to improve the therapeutic index and reduce the side effects. In this study LDE was used as vehicle to di-dodecyl methotrexate, a lipophilic derivative of MTX, obtained through an esterification reaction with a high yield. The increased lipophilicity of the derivative allowed a high association to LDE and good stability. The IC50 of LDE-di-dodecyl MTX was lower than that of the MTX and the uptake was higher in leukemic cells. The MTX toxicity in mice was reduced after association to LDE, showing that LDE is a promising vehicle to this drug.

Introdução: O Câncer de próstata metastático (mCaP) é uma doença incurável com progressão para o mCaP resistente à castração (mCPRC) após terapia de deprivação androgênica. Os microRNAs (miR) -23b e -27b tem ação antioncogênica e são suprimidos neste contexto. O gene da ciclina G1 (CCNG1) codifica uma quinase dependente de ciclina com potencial de inibição do crescimento e é um dos alvos dos miR-23b/-27b. Objetivos: Estimular os miR-23b/-27b isoladamente e em conjunto para avaliar e comparar o crescimento tumoral e a expressão do gene alvo CCNG1 em relação ao grupo controle em xenenxertos de PC-3M-luc-C6 em camundongos atímicos castrados. Métodos: Xenoenxertos subcutâneos da linhagem celular PC-3M-luc-C6 foram implantados em camundongos machos BALB/c nude. Os animais foram castrados 10 dias após o implante e utilizamos injeções intratumorais para induzir o aumento da expressão dos miR-23b/-27b separadamente e em conjunto através de Pre-miR® específicos. Realizamos avaliações semanais da bioluminescência (BLI) para avaliar o crescimento tumoral após a castração. Utilizamos a reação em cadeia de polimerase reversa em tempo real (qRT-PCR) para analisar a expressão da CCNG1 e os animais foram sacrificados 21 dias após a castração. Dividimos um total de 21 xenoenxertos nos seguintes grupos de tratamento: 4 no grupo controle, 5 no grupo Pró miR-23b, 6 no grupo Pró miR-27 e 6 no grupo Pró miR-23b associado ao Pró miR-27b. Resultados: Confirmamos o sucesso da transfecção dos miRs por qRT-PCR, e apresentamos o achado de superexpressão relativa da CCNG1 em relação ao grupo controle em: 9% (p=0,76), 46% (p=0,05) e 203% (p=0,01) nos grupos Pró miR-23b, Pró miR-27b e Pró miR-23b associado ao Pró miR-27b respectivamente. Comparamos o crescimento proporcional de cada tumor através da BLI, por meio da leitura no momento da castração ao final do experimento. Obtivemos um crescimento de 13,5; 8,69; 5,96 e 9,98 vezes nos grupos: controle, Pró miR-23b, Pró miR-27b e Pró miR-23b associado ao Pró miR-27b respectivamente. Conclusão: Demonstramos um modelo in vivo de CPRC que apresentou supreexpressão da CCNG1 após o tratamento intratumoral que aumentou a expressão dos miRs -23b e -27b. Este conjunto de miRs tem ação antioncogênica descrita no contexto do mCPRC e a sua estimulação neste contexto aumentou a expressão da CCNG1. Nosso estudo sugere que a CCNG1 deve apresentar uma ação pró-apoptótica quando superexpresso pelos miRs-23b/-27 no CPRC / Introduction: Metastatic prostate cancer (mPCa) is an incurable disease that invariably progresses to castration-resistant mPCa (mCRPC) after androgen deprivation therapy. The microRNAs miR-23b/-27b have been reported as tumor suppressors and are underexpressed in this context. The cyclin G1 gene (CCNG1) encodes a cyclin-dependent kinase with potential growth inhibitory activity that is a potential target of miR-23b/-27b. Objectives: We aim to explore a bioluminescent xenograft model of CRPC in castrated mice the effect positive modulation of the miR-23b/-27b on CCNG1 expression and mCRPC growth. Material and Methods: We injected subcutaneous xenografts of PC-3M-luc-C6 PCa cell line in BALB/c nude male mice. We neutered the animals after 10 days and used intratumoral injections up-regulating miR-23b/-27b separately and simultaneously through specific Pre-miRTM. We used weekly bioluminescence imaging (BLI) to assess tumor growth after castration and real-time polymerase chain reaction (qRT-PCR) to analyze the expression of CCNG1. We sacrificed the animals 21 days after castration. We randomized 21 xenografts in experimental groups as follows: n=4 in the negative control group; n=5 in Pro miR-23b group; n=6 in Pro miR-27b group and an n=6 tumors in the Pro miR-23b plus Pro miR-27b. Results: We confirmed successful transfection of both miRNAs with overexpression of CCNG1 of 9% (p=0.76), 46% (p=0.05) and 203% (p=0.01) in the Pro miR-23b, Pro miR-27b and Pro miR-23b plus -27b groups respectively. We compared the fold-change in BLI growth by the end of experiment finding an increase of 13.5-fold, 8.69-fold, 5.96-fold and 9.98-fold in groups Pro miR-negative control, Pro miR-23b, Pro miR-27b and Pro miR-23b plus Pro miR-27b groups respectively. Conclusions: We showed an in vivo model with overexpression of CCNG1 upon artificial upregulation of miR-23b and -27b in CRPC. This cluster of antineoplastic miRNA increased the expression of this cyclin, often described as oncogenic. Our study suggests that CCNG1 has a pro-apoptotic role when up-regulated by miR-23b/-27b in CPRC

The thesis “Ancillary Ligand Effects on the Anticancer Activity of Ruthenium (II) Piano Stool Complexes” is an effort to design better antitumor metallodrugs based on ruthenium(II) complexes with various H-bond donor/acceptor ligands and to understand their mechanism of action. Chapter 1 presents a brief review of metallodrugs and their mechanism of action. Different classes of metallodrugs are discussed. A short discussion on ruthenium based anticancer drugs and their established mechanism of action is also included in this chapter. Chapter 2 deals with the synthesis, characterization and anticancer activity of Ru(II) complexes with P(III) and P(V) ligands. The effect of a strong hydrogen bond acceptor on the cytotoxicity of the complexes has been investigated which allows comparison of complexes with ligands possessing a strong hydrogen bond donor or hydrogen bond acceptor. Partial oxidation of the tertiary phosphine ligands leads to a decrease in cytotoxicity of the ligand, while coordination to ruthenium resulted in a significant increase in the cytotoxicity. A molecular mechanism of action for these complexes was suggested on the basis of various biophysical studies. These complexes bind DNA through non-intercalative interactions which lead to the destabilization of the double helix of the DNA and also unwinding of the negatively supercoiled DNA. Results show that the presence of a hydrogen bond acceptor on the ligand is not capable of enhancing interactions with DNA in comparison with hydrogen bond donor groups. Cellular studies of these complexes showed that inhibition of DNA synthesis and apoptosis occur on treatment with these complexes. Interestingly, these complexes are found to be not only cytotoxic but also antimetastatic. Chapter 3 deals with the synthesis, characterization and anticancer activity of Ru(II) complexes with biologically active S containing heterocyclic ligands and their mechanistic study. Complexation of ruthenium with mercaptobenzothiazole (MBT) gave the most cytotoxic complex (H3) in the series. Heterocyclic Ru(II) complexes behave differently as evidenced by cellular and biophysical studies. Unlike phosphine complexes, H3 shows biphasic melting of DNA at higher concentrations which suggests two different types of interaction with DNA. Chapter 4 deals with synthesis and characterization of water soluble multiruthenated hydrophilic ruthenium(II) complexes with urotropine. An increase in cytotoxicity and binding affinity has been observed with increase in the number of ruthenium atoms per molecule. The complex with three ruthenium atoms showed the best activity. However cytotoxicity of the complexes decreases with decrease in the lipophilicity of the complexes. Chapter 5 describes studies on the interaction of Ru complexes with water, ss-DNA, AMP, GMP and GSH by various spectroscopic techniques. Hydrolysis of Ru-Cl bond in the complexes correlates with the cytotoxicity. Chapter 6 reports the summary of the observations of the thesis and the future prospects of metallodrugs.

This thesis deals with the development and application of methods for asymmetric olefinations, in particular Horner-Wadsworth-Emmons (HWE) reactions, in the synthesis of certain natural products. Relying on asymmetric HWE reactions to access key building blocks, two natu-ral products, pyranicin and pyragonicin, were synthesized from common late intermediates. The utility of the HWE reactions is highlighted through a desymmetrization of a meso-dialdehyde as well as a stereoconvergent reaction sequence employing the sequential use of a HWE parallel kinetic resolution fol-lowed by a Pd-catalyzed allylic substitution to convergently transform a race-mate to a single stereoisomer of the product. Methodological extensions of these syntheses include a divergent synthesis of 2,3,6-substituted tetrahydropyran derivatives and application of Zn-mediated asymmetric alkynylations to install key stereocenters. Synthetic studies directed towards a more complex target, mucocin, employing a triply convergent strategy, have also been performed. Expedient and reliable routes to three key fragments were developed, as well as methodology to access to all nine stereocenters. The fragment coupling to assemble the oligonuclear core still remains a challenge, however. Key features of the synthesis include the formation of two fragments from a common precursor derived from an asymmetric HWE desymmetrization, Zn-mediatedated asymmetric alkynylations, a stereoselective oxa-Michael cyclization dependent on a simultaneous protective group migration and a one-pot procedure for the synthesis of a TBS protected iodohydrin from a terminal epoxide. An investigation of the possibilities for developing a transition metal catalyzed asymmetric olefination using a chiral Re-complex is outlined. An enantioen-riched BINAP-Re complex was synthesized and characterized by X-ray. An efficient protocol for the olefination of functionalized aldehydes employing this catalyst was developed, but gave racemic products in two attempted kinetic resolutions of racemic substrates, most likely due to a reaction pathway proceeding via a non-metal associated phosphonium ylide. / QC 20100921