A colonoscopia é atualmente o padrão ouro para investigação da mucosa dos cólons, reto e íleo terminal. Para sua realização, há necessidade de uso de soluções para limpeza do cólon que, em geral, são mal toleradas pelos pacientes. Os objetivos do presente estudo foram comparar duas soluções de preparo intestinal para colonoscopia, quanto à efetividade, tolerabilidade, aceitabilidade e segurança em pacientes que se submeteriam a colonoscopia eletivamente, no Centro de Diagnóstico em Gastroenterologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Trata-se de estudo unicêntrico, prospectivo, com alocação aleatória dos pacientes. Cem pacientes pareados por sexo e idade foram randomizados em dois grupos. O grupo I recebeu bisacodil mais 1 litro de Polietilenoglicol (PEG) na véspera e 1 litro no dia do exame. O grupo II recebeu bisacodil na véspera e 1 litro de manitol 10% no dia do exame. A mesma dieta foi orientada nos dois grupos. A qualidade do preparo foi graduada através das escalas de Boston e Ottawa. A tolerabilidade e aceitabilidade foram aferidas por questionários previamente estudados. Quanto à segurança, foram ava liadas: variação de sinais vitais antes e após o preparo e complicações. Noventa e seis pacientes (96%) completaram o estudo. Não se observou diferença na qualidade do preparo entre os grupos(p = 0,059). Quanto à tolerabilidade, o grupo I (PEG) apresentou frequência significativamente menor de náusea, vômito, dor abdominal e distensão abdominal (p < 0,05). A aceitabilidade foi significativamente melhor com o grupo I (PEG) (p < 0,05). Em relação à segurança, o grupo I (PEG) apresentou-se mais seguro. No presente estudo, podemos concluir que ambos os preparos são semelhantes em eficácia (p > 0,05) e a solução de PEG apresentou melhor tolerabilidade, aceitabilidade e segurança em comparação ao preparo com manitol (p < 0,05). / Colonoscopy is currently the gold standard to examine the colon, the rectum, and the terminal ileum. To perform a colonoscopy, is necessary to use solutions to clean the colon that are generally poorly tolerated by the patients. The study aims to compare the effectiveness, tolerability, acceptability and safety of two solutions used for intestinal preparation for elective colonoscopy examination in the Diagnosis Center Of Hospital das Clinicas, Faculty of Medicine, University of São Paulo. It is a Prospective study carried out in a single center, with random allocation of the patients. One hundred patients that were paired based on sex and age were randomized into two groups. Group I received bisacodyl plus 1 liter of polyethylene glycol (PEG) the night before and 1 liter on the day of the exam. Group II received bisacodyl the night before and 1 liter of a 10% mannitol solution on the day of the exam. The patients diet was the same for both groups. The quality of the preparation was graded based on the Boston and Ottawa scales. Tolerability and acceptability were measured using previously validated questionnaires. In terms of safety, variations in vital signs before and after the preparation were recorded, as well as any complications. Ninety-six patients (96%) completed the study. No difference was observed in the quality of the preparation between the two preparation methods (p = 0,059). As for tolerability, group II (the mannitol preparation group) presented a significantly higher frequency of nausea, vomiting, abdominal pain and abdominal distension (p < 0,05). Acceptability was significantly better in group I (p < 0,05). The PEG solution was also shown to be safer than mannitol. Based on the present study, the following conclusions can be made: 1) Both methods of preparation had similar efficiencies (p > 0,05); 2) PEG method showed higher tolerability, acceptability and safety compared to the mannitol method (p < 0,05).

A colonoscopia é atualmente o padrão ouro para investigação da mucosa dos cólons, reto e íleo terminal. Para sua realização, há necessidade de uso de soluções para limpeza do cólon que, em geral, são mal toleradas pelos pacientes. Os objetivos do presente estudo foram comparar duas soluções de preparo intestinal para colonoscopia, quanto à efetividade, tolerabilidade, aceitabilidade e segurança em pacientes que se submeteriam a colonoscopia eletivamente, no Centro de Diagnóstico em Gastroenterologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Trata-se de estudo unicêntrico, prospectivo, com alocação aleatória dos pacientes. Cem pacientes pareados por sexo e idade foram randomizados em dois grupos. O grupo I recebeu bisacodil mais 1 litro de Polietilenoglicol (PEG) na véspera e 1 litro no dia do exame. O grupo II recebeu bisacodil na véspera e 1 litro de manitol 10% no dia do exame. A mesma dieta foi orientada nos dois grupos. A qualidade do preparo foi graduada através das escalas de Boston e Ottawa. A tolerabilidade e aceitabilidade foram aferidas por questionários previamente estudados. Quanto à segurança, foram ava liadas: variação de sinais vitais antes e após o preparo e complicações. Noventa e seis pacientes (96%) completaram o estudo. Não se observou diferença na qualidade do preparo entre os grupos(p = 0,059). Quanto à tolerabilidade, o grupo I (PEG) apresentou frequência significativamente menor de náusea, vômito, dor abdominal e distensão abdominal (p < 0,05). A aceitabilidade foi significativamente melhor com o grupo I (PEG) (p < 0,05). Em relação à segurança, o grupo I (PEG) apresentou-se mais seguro. No presente estudo, podemos concluir que ambos os preparos são semelhantes em eficácia (p > 0,05) e a solução de PEG apresentou melhor tolerabilidade, aceitabilidade e segurança em comparação ao preparo com manitol (p < 0,05). / Colonoscopy is currently the gold standard to examine the colon, the rectum, and the terminal ileum. To perform a colonoscopy, is necessary to use solutions to clean the colon that are generally poorly tolerated by the patients. The study aims to compare the effectiveness, tolerability, acceptability and safety of two solutions used for intestinal preparation for elective colonoscopy examination in the Diagnosis Center Of Hospital das Clinicas, Faculty of Medicine, University of São Paulo. It is a Prospective study carried out in a single center, with random allocation of the patients. One hundred patients that were paired based on sex and age were randomized into two groups. Group I received bisacodyl plus 1 liter of polyethylene glycol (PEG) the night before and 1 liter on the day of the exam. Group II received bisacodyl the night before and 1 liter of a 10% mannitol solution on the day of the exam. The patients diet was the same for both groups. The quality of the preparation was graded based on the Boston and Ottawa scales. Tolerability and acceptability were measured using previously validated questionnaires. In terms of safety, variations in vital signs before and after the preparation were recorded, as well as any complications. Ninety-six patients (96%) completed the study. No difference was observed in the quality of the preparation between the two preparation methods (p = 0,059). As for tolerability, group II (the mannitol preparation group) presented a significantly higher frequency of nausea, vomiting, abdominal pain and abdominal distension (p < 0,05). Acceptability was significantly better in group I (p < 0,05). The PEG solution was also shown to be safer than mannitol. Based on the present study, the following conclusions can be made: 1) Both methods of preparation had similar efficiencies (p > 0,05); 2) PEG method showed higher tolerability, acceptability and safety compared to the mannitol method (p < 0,05).

Les glioblastomes sont des tumeurs primaires du cerveau les plus malignes. L’identification des cellules souches cancéreuses de glioblastome (CSGs) a transformé notre vision globale des glioblastomes en révélant une hiérarchie cellulaire au sein de ces tumeurs. Les CSGs sont douées de propriétés d’auto-renouvellement, de différenciation et peuvent entrer en quiescence. Elles sont considérées comme les cellules entretenant les tumeurs, responsables de leur dissémination et des rechutes après traitement. La découverte des CSGs a conduit à un changement de paradigme dans le développement des thérapies anticancéreuses, avec la nécessité de cibler dans le traitement non seulement les cellules de la masse tumorale, mais aussi les CSGs. Un criblage différentiel de la chimiothèque Prestwick réalisé au laboratoire a permis d’identifier le bisacodyl comme une molécule présentant une cytotoxicité spécifique sur les CSGs en quiescence.Cette thèse présente un travail sur la caractérisation des CSGs, la compréhension du mode d’action du bisacodyl, ainsi que l’évaluation de son potentiel thérapeutique sur un modèle 3D in intro et des modèles in vivo. / Glioblastomas are the most malignant primary brain tumors. The identification of glioblastoma stemcells (GSCs) has transformed our comprehension of those tumors by revealing a hierarchical organization. GSCs can self-renew, differentiate and enter into a quiescent state. They are considered as cells which fuel and as the main culprits of tumor relapse. The discovery of GSCs triggered a change in paradigm for cancer therapy. Indeed to gain in efficacy, therapies need to target, not only the cells forming the bulk of the tumor, but also GSCs particularly resistant and endowed with a high tumorigenic potential. Chemical screening of the Prestwick chemical library in our laboratory, unveiled bisacodyl with a specific activity on quiescent GSCs.This thesis presents work on the characterization of GSCs, study of the mode of action of bisacodyl on GSCs, as well as a preclinical evaluation of bisacodyl on a 3D model in vitro and animal models in vivo.

Les glioblastomes (GBM) sont les formes les plus agressives de tumeurs gliales avec une survie médiane des patients traités n’excédant pas 2 ans. Ce mauvais pronostic est dû, entre autres, à l’hétérogénéité de ces tumeurs avec la présence de cellules souches cancéreuses (CSCs) en prolifération ou quiescentes, particulièrement résistantes aux traitements conventionnels. Cibler ces cellules au sein du microenvironment tumoral hypoxique et acides fait donc partie des thérapies d’avenir des GBMs. Le laxatif bisacodyl a été identifié par criblage de la chimiothèque Prestwick comme un composé induisant la mort par nécrose des CSCs de glioblastome (GSCs en prolifération et en quiescence), uniquement dans des conditions de faible acidité retrouvées également au sein des tumeurs. Une activité antitumorale in vivo a également été démontrée pour ce composé. Cette thèse présente l’identification du mode d’action du bisacodyl dans les GSCs. Celui-ci implique la serine/thréonine kinase WNK1 et ses partenaires, les kinases Akt et SGK1 et des co-transporteurs Na+/HCO3- NBC. Nos résultats ont également révélé un rôle de WNK1 dans la physiopathologie des GSCs. / Glioblastoma (GBM), the most aggressive glial tumor, is currently incurable with a very short-term patient survival (< 2 years). The heterogeneity of GBM and the presence of highly resistant proliferating and quiescent cancer stem-like cells (CSCs), is largely responsible for poor prognosis in this disease. Thus, new approaches targeting glioblastoma CSCs (GSCs), within the acidic/hypoxic tumor microenvironment, are promising strategies for treating GBM. The laxative bisacodyl was identified in a high throughput screening of the Prestwick chemical library as a compound inducing necrotic cell death in proliferating and quiescent GSCs only in acidic microenvironments similar to those found in tumors. Bisacodyl was further shown to induce tumor shrinking and to increase survival in in vivo GBM models. In this thesis work, we identify bisacodyl’s mechanism of action in GSCs. This mechanism involves the serine/threonine kinase WNK1 and its signaling partners including protein kinases Akt and SGK1 and NBC Na+/HCO3- cotransporters. Our data also highlight a previously unknown role of WNK1 in GSC physiopathology.