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Ewing sarcoma, an aggressive primary bone and soft tissue tumour is characterised by the expression of the chimeric transcription factor EWS-FLI1 in 90% of patients. This alters expression of many genes including activation of the Insulin Growth Factor (IGF) pathway via IGFBP3 supression. Phase I/II trials with an IGF-1 inhibitor have demonstrated tumour regression in a modest number of Ewing sarcoma patients. The aim of this thesis was to identify mechanisms contributing to the heterogeneity of resistance in Ewing sarcoma following inhibition with OSI-906, a dual kinase inhibitor of IGF-1 (IGF-1R) and Insulin (IR) receptors. The hypothesis was that mechanisms of resistance relate to heterogeneity of responses to signalling pathway activation and inhibition. Through selection, disruption of the pathway would identify subpopulations of cells both sensitive and resistant in their response allowing for interrogation of resistance mechanisms. A genome wide approach was taken to model the resistance profile of cell lines. Through developing a method of unbiased quantification, a panel of validated Ewing sarcoma cell lines (EuroBoNet) were imaged and segmented to assess the responses of biomarkers on signalling pathway activation. Heterogeneity was confirmed between cell lines. The application to diagnostic biopsies led to the identification of prognostic classifiers and cellular subpopulations with clinical prognostic significance. The distribution of Ki67 was found to be predictive of survival and cells with lower levels of CD99 in the cytoplasm were most discriminative. Parallel sequencing strategies (RNA-seq, whole exome sequencing, and aCGH/ SNP array) for genome-wide screening was carried out for point mutations, copy number changes and rearrangements. Systematic detection was used to characterise genomic rearrangements and functional validation performed. Resistant clones, formed via ENU mutagenesis of cell lines, were sequenced in order to demonstrate the resistance profile of OSI-906. In summary heterogeneity of Ewing sarcoma at the genomic and proteomic level can influence the signalling dependency of tumours and response to inhibitors. Genomic and proteomic profiling of tumour cells may be relevant to future developments of novel therapies.

O sarcoma de Ewing é uma neoplasia maligna agressiva que acomete ossos e tecidos moles com maior frequência em crianças e adolescentes. O tratamento consta de quimioterapia de indução, seguida pelo controle local da doença (cirurgia, cirurgia associada à radioterapia, ou apenas radioterapia), e quimioterapia de consolidação. A introdução da quimioterapia possibilitou aumento significativo na sobrevida dos pacientes nas últimas décadas. Por outro lado, o impacto da modalidade de controle local ainda não está bem estabelecido. Estudos observacionais têm demonstrado superioridade do tratamento cirúrgico em relação à radioterapia isolada, no entanto, são limitados os estudos prospectivos que confirmam esta diferença. O objetivo deste estudo é avaliar o impacto da modalidade de tratamento local nos desfechos oncológicos, bem como descrever o perfil clínico-epidemiológico de portadores de sarcoma de Ewing ósseo não-metastático. Os dados foram coletados em 15 instituições no período entre 2003 e 2010 e fazem parte do primeiro estudo do Grupo Colaborativo Brasileiro para Tratamento dos Tumores da Família Ewing (EWING I). Dos 73 pacientes incluídos, 47 foram tratados com cirurgia isolada, 13 receberam cirurgia associada à radioterapia, e 13 apenas radioterapia. O seguimento médio foi de 4,5 anos (2,3 até 6,7 anos) e a sobrevida geral e livre de eventos foi de 63,3 e 62,1 por cento em 5 anos, respectivamente. A falha do tratamento local foi de 0 (zero) por cento para a modalidade de cirurgia associada à radioterapia, 6,5 por cento para cirurgia isolada, e 10 por cento para radioterapia (p=0,5). A sobrevida dos pacientes submetidos à radioterapia isolada foi significativamente inferior à sobrevida dos tratados com cirurgia e com cirurgia associada a radioterapia (30,8 versus 71,7 versus 64,1 por cento, respectivamente). Concluiu-se que não houve diferença em termos de falha local de acordo com a modalidade de tratamento empregada, no entanto houve diferença significativa em termos de sobrevida. Apesar dos resultados cirúrgicos superiores, a radioterapia isolada ainda apresenta papel fundamental no tratamento de casos selecionados. / Ewing sarcoma is a small round cell malignancy of bone and soft tissue that usually occurs in children and adolescents. Current treatment includes induction chemotherapy, local control of the primary tumor (surgery, surgery plus radiotherapy, or radiotherapy) and consolidation chemotherapy. The introduction of chemotherapy has improved significantly the oncologic outcomes in Ewing sarcoma. On the other hand, the impact of the local control modality has not been established. Surgery alone or in combination with radiation has traditionally been considered a good choice for resectable ES, while unresectable tumors have been treated with definitive radiotherapy. Despite the results from a few trials and observational studies, there is no consistent knowledge about the local control modality in ES outcomes. The present study aims to evaluate the impact of the local control modality in the oncologic outcomes, as well as to describe the clinical features of the patients with localized Ewing sarcoma of the bone. The data were collected between 2003 and 2010 in 15 hospitals and were part of the first Brazilian Collaborative Group for the Treatment of the Ewing Sarcoma Family Tumors (EWING 1). From 73 patients (median age 12.8 years old), 47 were treated with surgery, 13 with surgery plus radiotherapy, and 13 with definitive radiotherapy. Median follow up was 4.5 years (2.3 to 6.7 years) and the overall and event-free survival 63.3 and 62.1 percent in 5 years, respectively. The local control failure was 0 percent for surgery plus radiotherapy, 6.5 percent for surgery, and 10 percent for radiotherapy (p=.5). The survival of the patients treated with radiotherapy was significantly worse than those treated with surgery and surgery plus radiotherapy (30.8 versus 71.7 versus 64.1 percent, respectively). In conclusion, there was no significant difference in local failure according to the modality of treatment, but there was significant difference in survival rates. Despite the better outcomes in individuals treated with surgery, the radiotherapy modality has still an important role in selected patients.

3D ex vivo tumor models are required which better replicate the microenvironment encountered by tumor cells in vivo. In this study, we applied bone tissue engineering culture techniques to develop an ex vivo 3D bone tumor model. Ewing sarcoma cells were cultured on poly(ε-caprolactone) (PCL) microfiber scaffolds, and cellular growth kinetics, morphology, and infiltration were assessed. Cell/scaffold constructs were then exposed to anticancer drugs for up to 16 days and drug response was compared to 2D controls. Ewing sarcoma cells were capable of attachment and proliferation on PCL scaffolds and dense scaffold infiltration up to 200 micrometers. Constructs could be maintained in culture for up to 32 days, and high density 3D cell growth conferred an increased resistance to anticancer drugs over 2D controls. This 3D tumor model shows potential for use in future studies of bone tumor biology, especially as it pertains to the development of new anticancer drugs.

O sarcoma de Ewing é uma neoplasia maligna agressiva que acomete ossos e tecidos moles com maior frequência em crianças e adolescentes. O tratamento consta de quimioterapia de indução, seguida pelo controle local da doença (cirurgia, cirurgia associada à radioterapia, ou apenas radioterapia), e quimioterapia de consolidação. A introdução da quimioterapia possibilitou aumento significativo na sobrevida dos pacientes nas últimas décadas. Por outro lado, o impacto da modalidade de controle local ainda não está bem estabelecido. Estudos observacionais têm demonstrado superioridade do tratamento cirúrgico em relação à radioterapia isolada, no entanto, são limitados os estudos prospectivos que confirmam esta diferença. O objetivo deste estudo é avaliar o impacto da modalidade de tratamento local nos desfechos oncológicos, bem como descrever o perfil clínico-epidemiológico de portadores de sarcoma de Ewing ósseo não-metastático. Os dados foram coletados em 15 instituições no período entre 2003 e 2010 e fazem parte do primeiro estudo do Grupo Colaborativo Brasileiro para Tratamento dos Tumores da Família Ewing (EWING I). Dos 73 pacientes incluídos, 47 foram tratados com cirurgia isolada, 13 receberam cirurgia associada à radioterapia, e 13 apenas radioterapia. O seguimento médio foi de 4,5 anos (2,3 até 6,7 anos) e a sobrevida geral e livre de eventos foi de 63,3 e 62,1 por cento em 5 anos, respectivamente. A falha do tratamento local foi de 0 (zero) por cento para a modalidade de cirurgia associada à radioterapia, 6,5 por cento para cirurgia isolada, e 10 por cento para radioterapia (p=0,5). A sobrevida dos pacientes submetidos à radioterapia isolada foi significativamente inferior à sobrevida dos tratados com cirurgia e com cirurgia associada a radioterapia (30,8 versus 71,7 versus 64,1 por cento, respectivamente). Concluiu-se que não houve diferença em termos de falha local de acordo com a modalidade de tratamento empregada, no entanto houve diferença significativa em termos de sobrevida. Apesar dos resultados cirúrgicos superiores, a radioterapia isolada ainda apresenta papel fundamental no tratamento de casos selecionados. / Ewing sarcoma is a small round cell malignancy of bone and soft tissue that usually occurs in children and adolescents. Current treatment includes induction chemotherapy, local control of the primary tumor (surgery, surgery plus radiotherapy, or radiotherapy) and consolidation chemotherapy. The introduction of chemotherapy has improved significantly the oncologic outcomes in Ewing sarcoma. On the other hand, the impact of the local control modality has not been established. Surgery alone or in combination with radiation has traditionally been considered a good choice for resectable ES, while unresectable tumors have been treated with definitive radiotherapy. Despite the results from a few trials and observational studies, there is no consistent knowledge about the local control modality in ES outcomes. The present study aims to evaluate the impact of the local control modality in the oncologic outcomes, as well as to describe the clinical features of the patients with localized Ewing sarcoma of the bone. The data were collected between 2003 and 2010 in 15 hospitals and were part of the first Brazilian Collaborative Group for the Treatment of the Ewing Sarcoma Family Tumors (EWING 1). From 73 patients (median age 12.8 years old), 47 were treated with surgery, 13 with surgery plus radiotherapy, and 13 with definitive radiotherapy. Median follow up was 4.5 years (2.3 to 6.7 years) and the overall and event-free survival 63.3 and 62.1 percent in 5 years, respectively. The local control failure was 0 percent for surgery plus radiotherapy, 6.5 percent for surgery, and 10 percent for radiotherapy (p=.5). The survival of the patients treated with radiotherapy was significantly worse than those treated with surgery and surgery plus radiotherapy (30.8 versus 71.7 versus 64.1 percent, respectively). In conclusion, there was no significant difference in local failure according to the modality of treatment, but there was significant difference in survival rates. Despite the better outcomes in individuals treated with surgery, the radiotherapy modality has still an important role in selected patients.

O sarcoma de Ewing é uma neoplasia maligna agressiva que acomete ossos e tecidos moles com maior frequência em crianças e adolescentes. O tratamento consta de quimioterapia de indução, seguida pelo controle local da doença (cirurgia, cirurgia associada à radioterapia, ou apenas radioterapia), e quimioterapia de consolidação. A introdução da quimioterapia possibilitou aumento significativo na sobrevida dos pacientes nas últimas décadas. Por outro lado, o impacto da modalidade de controle local ainda não está bem estabelecido. Estudos observacionais têm demonstrado superioridade do tratamento cirúrgico em relação à radioterapia isolada, no entanto, são limitados os estudos prospectivos que confirmam esta diferença. O objetivo deste estudo é avaliar o impacto da modalidade de tratamento local nos desfechos oncológicos, bem como descrever o perfil clínico-epidemiológico de portadores de sarcoma de Ewing ósseo não-metastático. Os dados foram coletados em 15 instituições no período entre 2003 e 2010 e fazem parte do primeiro estudo do Grupo Colaborativo Brasileiro para Tratamento dos Tumores da Família Ewing (EWING I). Dos 73 pacientes incluídos, 47 foram tratados com cirurgia isolada, 13 receberam cirurgia associada à radioterapia, e 13 apenas radioterapia. O seguimento médio foi de 4,5 anos (2,3 até 6,7 anos) e a sobrevida geral e livre de eventos foi de 63,3 e 62,1 por cento em 5 anos, respectivamente. A falha do tratamento local foi de 0 (zero) por cento para a modalidade de cirurgia associada à radioterapia, 6,5 por cento para cirurgia isolada, e 10 por cento para radioterapia (p=0,5). A sobrevida dos pacientes submetidos à radioterapia isolada foi significativamente inferior à sobrevida dos tratados com cirurgia e com cirurgia associada a radioterapia (30,8 versus 71,7 versus 64,1 por cento, respectivamente). Concluiu-se que não houve diferença em termos de falha local de acordo com a modalidade de tratamento empregada, no entanto houve diferença significativa em termos de sobrevida. Apesar dos resultados cirúrgicos superiores, a radioterapia isolada ainda apresenta papel fundamental no tratamento de casos selecionados. / Ewing sarcoma is a small round cell malignancy of bone and soft tissue that usually occurs in children and adolescents. Current treatment includes induction chemotherapy, local control of the primary tumor (surgery, surgery plus radiotherapy, or radiotherapy) and consolidation chemotherapy. The introduction of chemotherapy has improved significantly the oncologic outcomes in Ewing sarcoma. On the other hand, the impact of the local control modality has not been established. Surgery alone or in combination with radiation has traditionally been considered a good choice for resectable ES, while unresectable tumors have been treated with definitive radiotherapy. Despite the results from a few trials and observational studies, there is no consistent knowledge about the local control modality in ES outcomes. The present study aims to evaluate the impact of the local control modality in the oncologic outcomes, as well as to describe the clinical features of the patients with localized Ewing sarcoma of the bone. The data were collected between 2003 and 2010 in 15 hospitals and were part of the first Brazilian Collaborative Group for the Treatment of the Ewing Sarcoma Family Tumors (EWING 1). From 73 patients (median age 12.8 years old), 47 were treated with surgery, 13 with surgery plus radiotherapy, and 13 with definitive radiotherapy. Median follow up was 4.5 years (2.3 to 6.7 years) and the overall and event-free survival 63.3 and 62.1 percent in 5 years, respectively. The local control failure was 0 percent for surgery plus radiotherapy, 6.5 percent for surgery, and 10 percent for radiotherapy (p=.5). The survival of the patients treated with radiotherapy was significantly worse than those treated with surgery and surgery plus radiotherapy (30.8 versus 71.7 versus 64.1 percent, respectively). In conclusion, there was no significant difference in local failure according to the modality of treatment, but there was significant difference in survival rates. Despite the better outcomes in individuals treated with surgery, the radiotherapy modality has still an important role in selected patients.

No description available.

No description available.

Les siRNA se sont des agents actifs et spécifiques couramment utilisés en thérapie génique. L’intérêt d’utiliser des nanoparticules en tant que vecteurs des siRNA est leur capacité à protéger ces derniers de la dégradation par les nucléases et également de leur permettre d’être délivrés au niveau de leur cible thérapeutique. Afin d’appuyer cette théorie, ce travail s’est concentré sur un modèle cellulaire de sarcome d’Ewing, dans le but de mettre au point un nouveau système galénique pour le transport de siRNA formé des nanoparticules bifonctionnelles de diamants fluorescentes recouvertes par des polymères cationiques. Ces nano-vecteurs sont capables d’induire efficacement l’inhibition de l’expression de l’oncogène EWS-Fli1 dans les cellules en culture s’ils transportent des siRNA dirigés contre ce gène. Par ailleurs, les nanodiamants, grâce à leurs propriétés de fluorescence stable et intense, ont constitué des outils de détection permettant de suivre leurs voies de pénétration, leur biodistribution cellulaire, ainsi que la cinétique de libération des siRNA dans le cytoplasme. Enfin, un modèle de nanodiamants fonctionnalisés par le polyéthylenimine a été choisi pour la poursuite des travaux biologiques en raison de son efficacité de vectorisation. / SiRNA are powerful and commonly used agent for the specific inhibition of gene expression. They need to be vectorized by nanoparticles to facilitate cell penetration and their protection from degradation in biological media. At first, cationic nanodiamonds coated with cationic polymers were developed and were able to adsorb siRNA on their surface. Using antisense siRNA against the oncogene EWS-Fli1, nanodiamonds allowed to efficiently induce the inhibition of expression of the oncogene EWS-FLI1 in cultured Ewing sarcoma cells. As a second goal of this study, the fluorescence of red color center created in the nanodiamonds was used to follow their pathways, their cellular biodistribution and the kinetics of release of siRNA into the cytoplasm. In conclusion, nanodiamonds functionalized by polyethylenimine showed a better transfection efficiency and were chosen for further biological studies.

Os sarcomas ósseos representam uma proporção significativa de tumores na faixa etária pediátrica, ainda apresentando um quadro desafiador devido a sua significativa taxa de morbimortalidade. Pesquisas para o desenvolvimento de novas modalidades terapêuticas e para o desenvolvimento de métodos que identifiquem características da doença que possam permitir melhor estratificação dos pacientes através de dados clinicamente relevantes para individualizar as condutas clínicas são necessárias. Dentro deste contexto surge o conceito de radiômica, que visa extrair dados clinicamente relevantes a partir de imagens médicas. Entretanto, para colocar a radiômica em prática, é necessário selecionar, nas imagens médicas, as áreas de interesse referentes às patologias estudadas, e este processo se denomina segmentação. O objetivo primário deste estudo foi avaliar a reprodutibilidade intra e inter-observador da segmentação manual de sarcomas ósseos em imagens de ressonância magnética (RM). Como objetivo secundário, foi avaliada a capacidade da segmentação semiautomática em reduzir o tempo necessário para segmentação, mantendo similaridade com a segmentação manual. O estudo foi realizado de forma retrospectiva com inclusão de pacientes com diagnóstico de osteossarcoma ou sarcoma de Ewing confirmado por estudo histopatológico e que tivessem imagens de RM realizadas no Hospital Universitário de nossa Instituição realizadas previamente a qualquer intervenção terapêutica. Três médicos radiologistas, de forma independente e às cegas em relação as demais segmentações e em relação ao resultado histopatológico, realizaram a segmentação manual dos contornos destes tumores utilizando o software 3DSlicer, permitindo que fosse realizada avaliação da reprodutibilidade interobservador. Um dos radiologistas realizou uma segunda segmentação manual dos mesmos casos, possibilitando a avaliação da reprodutibilidade intraobservador, e, ainda, uma terceira segmentação foi realizada, utilizando metodologia semiautomática, disponível no software mencionado. Para a análise estatística, foi utilizado o coeficiente de similaridade de Dice (DICE), a distância Hausdorff (DH), comparações de volumes e análises dos intervalos de tempo necessários para realização das segmentações. Os parâmetros avaliados demonstraram haver boa reprodutibilidade intraobservador, com DICE variando entre 0,83 a 0,97; e distância Hausdorff variando entre 3,37 a 28,73 mm. Também foi demonstrada boa reprodutibilidade interobservador com DICE variando entre 0,73 a 0,97; e distância Hausdorff variando entre 3,93 a 33,40 mm. A segmentação semiautomática demonstrou boa similaridade em relação à segmentação manual (DICE variando entre 0,71 a 0,96 e DH variando entre 5,38 a 31,54 mm), havendo redução significativa do tempo necessário para segmentação. Entre todas as situações comparadas, os volumes não apresentaram diferenças estatisticamente significativas (p-valor>0,05). / Bone sarcomas represent a significant proportion of tumors in the pediatric age group and they still are a challenge due to their significant morbidity and mortality rates. Reseaches are important for the development of new therapeutic modalities and for the development of methods that identify features that allow better stratification of the patients with theses diseases for individualization of their treatments. In this context emerges the concept of radiomics, which is the process of extraction of clinically relevant data from medical images. It is important to segment the areas of interest im medical images for the pratice of this process. The primary objective of this study was to evaluate the intra- and interobserver reproducibility of manual segmentation of bone sarcomas on magnetic resonance imaging (MRI). As a secondary objective, it was evaluated if the semiautomatic segmentation could be similar to manual segmentation and if the semiautomatic method could reduce the time required for segmentation. The study was performed retrospectively with the inclusion of patients with osteosarcoma or Ewing sarcoma confirmed by histopathological study and who had MRI performed at the University Hospital of our Institution prior to any therapeutic intervention. Three radiologists, independently and blindly in relation to the other segmentations and in relation to the histopathological results, performed the manual segmentation of the contours of these tumors using 3DSlicer software, allowing an interobserver reproducibility evaluation. One of the radiologists performed a second manual segmentation of the same cases, allowing the evaluation of intraobserver reproducibility. A third segmentation was performed, using semi-automatic methodology, available in the mentioned software. For the statistical analysis, Dice similarity coefficient (DICE), Hausdorff distance (DH), comparisons between volumes and time intervals for segmentations were used. The parameters evaluated demonstrated a good intraobserver reproducibility, with DICE ranging from 0.83 to 0.97 and Hausdorff distance ranging from 3.37 to 28.73 mm. Good interobserver reproducibility was also demonstrated with DICE ranging from 0.73 to 0.97 and Hausdorff distance ranging from 3.93 to 33.40 mm. Semiautomatic segmentation demonstrated good similarity to manual segmentation (DICE ranging from 0.71 to 0.96 and HD ranging from 5.38 to 31.54mm), and there was significant reduction in the time required for segmentation. Among all the situations compared, the volumes did not present significant statistical differences (p-value> 0.05).