O glioblastoma multiforme (GBM) é um tipo de câncer grave que acomete o sistema nervoso central (SNC), e a sobrevida dos pacientes é de aproximadamente 12 meses. O tratamento com o quimioterápico paclitaxel (PTX) reduz o GBM experimental e humano. No entanto, sua utilização é limitada pelas reações adversas graves que acarreta. A nanoemulsão rica em colesterol (LDE), a qual mimetiza a lipoproteína de baixa densidade, tem sido empregada como um sistema de entrega de fármacos eficiente em alguns casos de tumores. No presente trabalho visou-se avaliar a eficácia do oleato de PTX (OPTX), um derivado mais lipofílico do que o PTX, associado a LDE (LDE-OPTX) em ensaios in vitro e in vivo. Inicialmente, células tumorais da linhagem de glioblastoma murino GL261 foram incubadas com PTX em solução ou com LDE-OPTX, nas concentrações de 1 ou 10 µM. Os resultados obtidos mostraram que o tratamento in vitro com PTX e o LDE-OPTX causa toxicidade in vitro em células GL261 pela redução da proliferação e indução de apoptose, e que ainda reduz a secreção de MCP-1 (proteína quimiotáxica de monócitos). Os ensaios in vivo mostraram a toxicidade intensa do PTX comercial, uma vez que os animais com GBM não sobreviveram ao tratamento com 75mg/Kg, i.p., a cada 3 dias, e foram a óbito a partir do oitavo dia de tratamento. Diferentemente, os animais tratados com a mesma dose de LDE-OPTX sobreviveram ao tratamento, sem sinais de toxicidade, mas os dados obtidos mostraram que este protocolo de tratamento não foi eficaz para redução do volume tumoral. Assim, os animais com GBM passaram a ser tratados com doses diárias, i.p., de 15 mg/kg de PTX ou de 75mg/Kg de LDE-OPTX. Os resultados obtidos mostraram a ineficácia e eficácia dos tratamentos com PTX e LDE-OPTX, respectivamente, em reduzir o GBM; no entanto os animais tratados com LDE-OPTX apresentaram redução no peso corporal e no número de linfócitos circulantes. Em conjunto, os dados obtidos mostram a habilidade de preparação LDE-OPTX causar toxicidade in vitro nas células GL261 e sua eficácia terapêutica em dose elevada, em reduzir o GBM em modelo murino. / Glioblastoma multiforme (GBM) is a type of severe cancer that affects the central nervous system, and patient survival is about12 months. The treatment with the chemotherapeutic paclitaxel (PTX) reduces the experimental and human GBM, however, their use is limited by side effects. The lipid nanoemulsion (LDE), that is mimetic to low density protein, has been employed as an efficient drug nanocarrier to treat cancer. Therefore, the present study aimed to assess the effectiveness of the oleate PTX (OPTX), a more lipophilic derivative of PTX, associated to (LDE), in in vitro and in vivo studies. Initially, glioblastoma murine strain GL261 was incubated with commercial PTX solution or LDE-OPTX at concentrations of 1 or 10 µM. Data obtained showed that treatment with PTX or LDE-OPTX caused in vitro toxicity to GL261 cells, by reducing the proliferation and inducing apoptosis. Moreover, both treatments reduced the secretion of monocyte chemotacticprotein-1 (MCP-1). In vivo experiments showed the severe toxicity of commercial PTX, as mice with GBM did not survive to the treatment with 75mg/kg, i.p., each 3 days, and died after 8 days of treatment. Conversely, animals treated with the same schedule of treatment with LDE-OPTX survived until the end of treatment, without any toxicity signal. Nevertheless, the treatment was not effective to reduce the GBM volume. Hence, other sets of animals with GBM were treated with daily i.p. dose of 15mg/kg of PTX or 75mg/kg of LDE-OPTX. Data obtained showed the inefficacy and efficacy of PTX and LDE-OPTX treatments, respectively, to reduce the volume of GBM. Nevertheless, mice treated with LDE-OPTX lost weight and lower number of circulating lymphocytes. Together, our data show the ability of LDE-OPTX treatment cause in vitro toxicity on GL261 cells e the in vivo therapeutic efficacy of higher doses on GBM murine model.

O glioblastoma multiforme (GBM) é um tipo de câncer grave que acomete o sistema nervoso central (SNC), e a sobrevida dos pacientes é de aproximadamente 12 meses. O tratamento com o quimioterápico paclitaxel (PTX) reduz o GBM experimental e humano. No entanto, sua utilização é limitada pelas reações adversas graves que acarreta. A nanoemulsão rica em colesterol (LDE), a qual mimetiza a lipoproteína de baixa densidade, tem sido empregada como um sistema de entrega de fármacos eficiente em alguns casos de tumores. No presente trabalho visou-se avaliar a eficácia do oleato de PTX (OPTX), um derivado mais lipofílico do que o PTX, associado a LDE (LDE-OPTX) em ensaios in vitro e in vivo. Inicialmente, células tumorais da linhagem de glioblastoma murino GL261 foram incubadas com PTX em solução ou com LDE-OPTX, nas concentrações de 1 ou 10 µM. Os resultados obtidos mostraram que o tratamento in vitro com PTX e o LDE-OPTX causa toxicidade in vitro em células GL261 pela redução da proliferação e indução de apoptose, e que ainda reduz a secreção de MCP-1 (proteína quimiotáxica de monócitos). Os ensaios in vivo mostraram a toxicidade intensa do PTX comercial, uma vez que os animais com GBM não sobreviveram ao tratamento com 75mg/Kg, i.p., a cada 3 dias, e foram a óbito a partir do oitavo dia de tratamento. Diferentemente, os animais tratados com a mesma dose de LDE-OPTX sobreviveram ao tratamento, sem sinais de toxicidade, mas os dados obtidos mostraram que este protocolo de tratamento não foi eficaz para redução do volume tumoral. Assim, os animais com GBM passaram a ser tratados com doses diárias, i.p., de 15 mg/kg de PTX ou de 75mg/Kg de LDE-OPTX. Os resultados obtidos mostraram a ineficácia e eficácia dos tratamentos com PTX e LDE-OPTX, respectivamente, em reduzir o GBM; no entanto os animais tratados com LDE-OPTX apresentaram redução no peso corporal e no número de linfócitos circulantes. Em conjunto, os dados obtidos mostram a habilidade de preparação LDE-OPTX causar toxicidade in vitro nas células GL261 e sua eficácia terapêutica em dose elevada, em reduzir o GBM em modelo murino. / Glioblastoma multiforme (GBM) is a type of severe cancer that affects the central nervous system, and patient survival is about12 months. The treatment with the chemotherapeutic paclitaxel (PTX) reduces the experimental and human GBM, however, their use is limited by side effects. The lipid nanoemulsion (LDE), that is mimetic to low density protein, has been employed as an efficient drug nanocarrier to treat cancer. Therefore, the present study aimed to assess the effectiveness of the oleate PTX (OPTX), a more lipophilic derivative of PTX, associated to (LDE), in in vitro and in vivo studies. Initially, glioblastoma murine strain GL261 was incubated with commercial PTX solution or LDE-OPTX at concentrations of 1 or 10 µM. Data obtained showed that treatment with PTX or LDE-OPTX caused in vitro toxicity to GL261 cells, by reducing the proliferation and inducing apoptosis. Moreover, both treatments reduced the secretion of monocyte chemotacticprotein-1 (MCP-1). In vivo experiments showed the severe toxicity of commercial PTX, as mice with GBM did not survive to the treatment with 75mg/kg, i.p., each 3 days, and died after 8 days of treatment. Conversely, animals treated with the same schedule of treatment with LDE-OPTX survived until the end of treatment, without any toxicity signal. Nevertheless, the treatment was not effective to reduce the GBM volume. Hence, other sets of animals with GBM were treated with daily i.p. dose of 15mg/kg of PTX or 75mg/kg of LDE-OPTX. Data obtained showed the inefficacy and efficacy of PTX and LDE-OPTX treatments, respectively, to reduce the volume of GBM. Nevertheless, mice treated with LDE-OPTX lost weight and lower number of circulating lymphocytes. Together, our data show the ability of LDE-OPTX treatment cause in vitro toxicity on GL261 cells e the in vivo therapeutic efficacy of higher doses on GBM murine model.

Glioblastoma, grade IV glioma, is the one of the deadliest cancers, with a median survival of only 12-15 months despite aggressive treatment including surgery, chemotherapy and radiation. One hallmark of glioblastoma is the morphological and functional abnormalization of tumor blood vessels. The molecular mechanisms involved in this process and their functional and pathological implications are not yet fully understood. Indentification of molecular mechanisms that underlie vascular abnormalization in GBM is necessary to develop efficient treatment regimens for normalizing vascular function. By analyzing the RNA-content of laser microdissected vessels from human biobank specimens using affymetrix microarray analysis, we found that the abnormal glioblastoma vessels have a distinct gene expression signature. We found 95 genes which were differentially expressed in grade IV glioma vessels as compared to vessels in low grade tumors and control brain. 78 of which were up-regulated while 17 were down-regulated. Many of these genes are regulated by VEGFA or TGFβ signaling. In addition, we show a significant increase in Smad signaling complexes in the vasculature of human glioblastoma in situ, suggesting that TGFβ signaling may play important role in vessel abnormalization. CD93 is a single-pass transmembrane glycoprotein, which we found to be up-regulated in high grade glioma. Vascular expression of CD93 correlates to tumor grade in human glioma. Moreover, high grade glioma patients with high CD93 expression in the vasculature are associate with poor prognosis. We found that knocking down CD93 in endothelial cells with siRNA clearly impaired endothelial cell adhesion, migration and tube formation due to defects in cytoskeletal rearrangement. In addition, tumor growth was severely delayed in the CD93-/- mice. Pleiotrophin, a multi-functional heparin-binding growth factor, promotes glioma growth in several ways. Here, we identify pleiotrophin as a driver of vascular abnormalization in glioma. We found that high pleiotrophin expression correlates with poor survival of patients with astrocytomas. Pleiotrophin overexpression in orthotopic GL261 gliomas increases microvessel density, enhances tumour growth and decreases survival. Vessels in pleiotrophin-expressing gliomas are poorly perfused and display a high degree of abnormality, coinciding with elevated levels of vascular endothelial growth factor (VEGF) deposited in direct proximity to the vasculature. In addition to its role in vessel abnormalization, pleiotrophin enhanced PDGF-B-induced gliomagenesis. Taken together, our results indicate that PTN has an important role in glioma initiation and establishment of the characteristic abnormal tumor vasculature in glioblastoma, identifying PTN as a potential target for therapy.

Les glioblastomes sont des tumeurs gliales de hautgrade qui restent incurables de nos jours. Le traitement recommandé (résection chirurgicale suivie d’un traitement de radiothérapie externe associé à la chimiothérapie) conduit à une augmentation de la médiane de survie des patients de quelques mois. De nouvelles stratégies notamment dans le champ des nanomédecines véhiculant un radioélément (émetteur ou ) ont été évaluées en clinique. La première partie,après avoir dressé l’état des lieux des technologies utilisées dans ce domaine, rend compte des critères importants à prendre en compte que sont le choix du radioélément, les modalités d’administration et les vecteurs utilisés. Elle se conclut par une présentation des études précliniques en cours dont l’utilisation de nanovecteurs encapsulant un radioisotope : lesLNC188Re-SSS. La deuxième partie illustre l’application thérapeutique sur un modèle murin de xénogreffe et montre une éradication de la tumeur initiale suite à un protocole personnalisé d’injection fractionnée par convection-enhanced delivery. Elle décrit également la distribution des LNC ainsi que les effets directs des radiations sur les cellules tumorales (cellules géantes atypiques, supposées polyploïdes), accompagnés par un infiltrat inflammatoire (immunité innée). Une évaluation complémentaire sur modèle murin GL261 a été réalisée et constitue la troisième partie de cette thèse. Le transfert de ces résultats à l’application clinique pourrait être facilité par le recours à un modèle canin de gliome spontané homologue à celui de l’homme, dont ce travail prépare l’utilisation, dans le but de valider les procédures d’injection intracérébrales automatisées. / High grade glial brain tumors are defined as glioblastomas. Nowadays, they are incurable. The current therapeutic purposal (surgical resection, external radiotherapy and chemotherapy) doesn’t extend the patients median survival time up to a few months. Newstrategies as nanomedicines loaded with a radionuclide( or  emitter) have been evaluated in clinical trials. As tate of the art of this domain’s technologies is described in a first part which analyses the important criteria to take account in vectorized radiotherapy like the radionuclides, the route of administration and the vectors used. Then, it is concluded with a presentation of preclinical on going studies as the use of nanovectors loaded with a radioisotope : the LNC188Re-SSS. The second part illustrates the therapeutical strategy application on a xenograft mice model. The data showan eradication of the tumor mass of treated mice withthe personalized convection-enhanced delivery offractionated radiotherapy. Furthermore, it describes the LNC distribution and the direct radiation effects on tumor cells (atypical giant cells, polyploïdy) supported by an inflammatory infiltration (innate immune effectors). An evaluation on the GL261 mice model has been realized and concerns the third part of this thesis. In perspectives, the transfer of these data to clinical trials could be facilitated thanks to the dog spontaneous glioma model. This tumor share characteristics with the human neoplasma. Finally, this work will aim to validate the automated intracranial injection procedures.

Multimodal treatment adding immunotherapy and photodynamic treatment (PDT) to standard therapy might improve the devastating therapeutic outcome of glioblastoma multiforme patients. As a first step, we provide investigations to optimize dendritic cell (DC) vaccination by using PDT and ionizing radiation (IR) to achieve maximal synergistic effects. In vitro experiments were conducted on murine glioblastoma GL261 cells, primary DCs differentiated from bone marrow and T cells, isolated from the spleen. Induction of cell death, reactive oxygen species, and inhibition of proliferation by tetrahydroporphyrin-tetratosylat (THPTS)-PDT and IR were confirmed by WST-1, LDH, ROS, and BrdU assay. Tumor cargo (lysate or cells) for DC load was treated with different combinations of THPTS-PDT, freeze/thaw cycles, and IR and immunogenicity analyzed by induction of T-cell activation. Cellular markers (CD11c, 83, 86, 40, 44, 69, 3, 4, 8, PD-L1) were quantified by flow cytometry. Cytotoxic T-cell response was evaluated by calcein AM assay. Immunogenicity of THPTS-PDT-treated GL261 cells lysate was superior to IR-treated lysate, or treated whole cells proven by increased DC phagocytosis, T-cell adhesion, proliferation, cytolytic activity, and cytokine release. These data strongly support the application of PDT together with IR for optimal immunogenic cell death induction in tumor cell lysate used to pulse DC vaccines.