Somatic mutations and single-cell transcriptomes reveal the root of malignant rhabdoid tumours.

Malignant rhabdoid tumour (MRT) is an often lethal childhood cancer that, like many paediatric tumours, is thought to arise from aberrant fetal development. The embryonic root and differentiation pathways underpinning MRT are not firmly established. Here, we study the origin of MRT by combining phylogenetic analyses and single-cell mRNA studies in patient-derived organoids. Comparison of somatic mutations shared between cancer and surrounding normal tissues places MRT in a lineage with neural crest-derived Schwann cells. Single-cell mRNA readouts of MRT differentiation, which we examine by reverting the genetic driver mutation underpinning MRT, SMARCB1 loss, suggest that cells are blocked en route to differentiating into mesenchyme. Quantitative transcriptional predictions indicate that combined HDAC and mTOR inhibition mimic MRT differentiation, which we confirm experimentally. Our study defines the developmental block of MRT and reveals potential differentiation therapies

Mesenchymal tumor organoid models recapitulate rhabdomyosarcoma subtypes

Rhabdomyosarcomas (RMS) are mesenchyme-derived tumors and the most common childhood soft tissue sarcomas. Treatment is intense, with a nevertheless poor prognosis for high-risk patients. Discovery of new therapies would benefit from additional preclinical models. Here, we describe the generation of a collection of 19 pediatric RMS tumor organoid (tumoroid) models (success rate of 41%) comprising all major subtypes. For aggressive tumors, tumoroid models can often be established within 4-8 weeks, indicating the feasibility of personalized drug screening. Molecular, genetic, and histological characterization show that the models closely resemble the original tumors, with genetic stability over extended culture periods of up to 6 months. Importantly, drug screening reflects established sensitivities and the models can be modified by CRISPR/Cas9 with TP53 knockout in an embryonal RMS model resulting in replicative stress drug sensitivity. Tumors of mesenchymal origin can therefore be used to generate organoid models, relevant for a variety of preclinical and clinical research questions

Mesenchymal tumor organoid models recapitulate rhabdomyosarcoma subtypes

Rhabdomyosarcomas (RMS) are mesenchyme-derived tumors and the most common childhood soft tissue sarcomas. Treatment is intense, with a nevertheless poor prognosis for high-risk patients. Discovery of new therapies would benefit from additional preclinical models. Here, we describe the generation of a collection of 19 pediatric RMS tumor organoid (tumoroid) models (success rate of 41%) comprising all major subtypes. For aggressive tumors, tumoroid models can often be established within 4–8 weeks, indicating the feasibility of personalized drug screening. Molecular, genetic, and histological characterization show that the models closely resemble the original tumors, with genetic stability over extended culture periods of up to 6 months. Importantly, drug screening reflects established sensitivities and the models can be modified by CRISPR/Cas9 with TP53 knockout in an embryonal RMS model resulting in replicative stress drug sensitivity. Tumors of mesenchymal origin can therefore be used to generate organoid models, relevant for a variety of preclinical and clinical research questions

Mundos mesclados, espaços segregados: cultura material, mestiçagem e segmentação no sítio Aldeia em Santarém (PA)

This article discusses the processes of cultural exchange between Portuguese, Portuguese-Brazilian, Amerindians, and mestizos based on the analysis of the material culture from households of Santarém (PA), occupied during the eighteenth and nineteenth centuries,. Although these social groups manipulated material culture aiming to express different values, related to hierarchy, social segmentation, and affirmation of identities, ambiguity also characterizes these assemblages. This material ambiguity informs about the mixtures of both practices and cultural references that brought about the building of a mestizo society.Com base na análise da cultura material proveniente de unidades domésticas do núcleo urbano de Santarém (PA), ocupadas nos séculos XVIII e XIX, o presente artigo discute os processos de trocas culturais entre portugueses, luso-brasileiros, indígenas e mestiços. Embora esses grupos sociais tenham manipulado a cultura material visando expressar diferentes valores, relacionados à hierarquia, segmentação social e afirmação de identidades, a ambigüidade é uma característica das amostras analisadas, informando sobre as misturas de práticas e de referenciais culturais que levaram à construção de uma sociedade mestiça

Applying organoid technology to pediatric cancer research:: towards organoid-directed treatment of pediatric kidney cancer patients

Pediatric renal tumors are among the most frequent malignancies in children. The majority of patients is diagnosed with Wilms tumors. While survival rates have reached 90%, patients still suffer from severe long-term side effects, caused by the harsh therapy regiments. Furthermore, patients affected by rarer renal tumor subtypes, such as malignant rhabdoid tumor of the kidney (MRTK) and recurrent relapsed Wilms tumor (RWT), carry a dismal prognosis. To improve survival rates and quality of life for pediatric renal tumor patients, alternative therapies need to be sought. In recent years therapeutic innovation has been impaired by different factors, including the lack of preclinical models able to closely represent characteristics of pediatric kidney tumors. New frontiers in cell culture techniques allow for the establishment and expansion of multicellular structures, derived from stem cells, that self-organize to grow in a 3D fashion. These “mini organs”, able to mimic the architecture – and partial function - of the original tissues, are named organoids. Organoids can be generated from healthy tissues as well as from tumors. Tumor organoids can be established with high efficiency from patient tumor material, while maintaining characteristics of the original tissue, such as histology and genetic makeup. Furthermore, several studies have shown that tumor organoids are able to mirror the response to therapy registered in patients, making them appealing models for drug screening purposes. In this thesis, we present for the first time the application of the organoid technology to pediatric cancer research. We successfully generated more than 50 unique patient-derived organoid cultures for which preclinical models were scarce. This collection of organoids provides with the opportunity to study these rare malignancies with the advantages of an in vitro model, while the characteristics of the original tumors are still recapitulated to a large extend. We demonstrate that it is feasible to use these models to perform drug screening and identify novel therapy for high-risk pediatric patients. The work presented in this thesis sets the first steps towards the implementation of the organoid technology as tool for improving treatment of children with cancer

Applying organoid technology to pediatric cancer research:: towards organoid-directed treatment of pediatric kidney cancer patients

Pediatric renal tumors are among the most frequent malignancies in children. The majority of patients is diagnosed with Wilms tumors. While survival rates have reached 90%, patients still suffer from severe long-term side effects, caused by the harsh therapy regiments. Furthermore, patients affected by rarer renal tumor subtypes, such as malignant rhabdoid tumor of the kidney (MRTK) and recurrent relapsed Wilms tumor (RWT), carry a dismal prognosis. To improve survival rates and quality of life for pediatric renal tumor patients, alternative therapies need to be sought. In recent years therapeutic innovation has been impaired by different factors, including the lack of preclinical models able to closely represent characteristics of pediatric kidney tumors. New frontiers in cell culture techniques allow for the establishment and expansion of multicellular structures, derived from stem cells, that self-organize to grow in a 3D fashion. These “mini organs”, able to mimic the architecture – and partial function - of the original tissues, are named organoids. Organoids can be generated from healthy tissues as well as from tumors. Tumor organoids can be established with high efficiency from patient tumor material, while maintaining characteristics of the original tissue, such as histology and genetic makeup. Furthermore, several studies have shown that tumor organoids are able to mirror the response to therapy registered in patients, making them appealing models for drug screening purposes. In this thesis, we present for the first time the application of the organoid technology to pediatric cancer research. We successfully generated more than 50 unique patient-derived organoid cultures for which preclinical models were scarce. This collection of organoids provides with the opportunity to study these rare malignancies with the advantages of an in vitro model, while the characteristics of the original tumors are still recapitulated to a large extend. We demonstrate that it is feasible to use these models to perform drug screening and identify novel therapy for high-risk pediatric patients. The work presented in this thesis sets the first steps towards the implementation of the organoid technology as tool for improving treatment of children with cancer

Correção cirúrgica de pseudoaneurismas e fístula arteriovenosa complexa entre vasos poplíteos

Resumo A fístula arteriovenosa (FAV) é uma comunicação anormal e permanente entre uma artéria e uma veia devido a traumas penetrantes e lesões iatrogênicas. O trauma penetrante na parede arterial pode levar à formação de pseudoaneurismas (PSA) e, se houver lesão venosa concomitante, à formação de uma FAV. Os autores apresentam o caso de um paciente portador de FAV complexa de vasos poplíteos associada a pseudoaneurisma de artéria poplítea, sugeridos a partir de exames clínicos e exames de imagem, e tratados por cirurgia convencional devido à indisponibilidade de um stent graft com diâmetro apropriado, além de a cirurgia endovascular não estar disponível no serviço em que o paciente foi operado

Somatic mutations and single-cell transcriptomes reveal the root of malignant rhabdoid tumours.

Malignant rhabdoid tumour (MRT) is an often lethal childhood cancer that, like many paediatric tumours, is thought to arise from aberrant fetal development. The embryonic root and differentiation pathways underpinning MRT are not firmly established. Here, we study the origin of MRT by combining phylogenetic analyses and single-cell mRNA studies in patient-derived organoids. Comparison of somatic mutations shared between cancer and surrounding normal tissues places MRT in a lineage with neural crest-derived Schwann cells. Single-cell mRNA readouts of MRT differentiation, which we examine by reverting the genetic driver mutation underpinning MRT, SMARCB1 loss, suggest that cells are blocked en route to differentiating into mesenchyme. Quantitative transcriptional predictions indicate that combined HDAC and mTOR inhibition mimic MRT differentiation, which we confirm experimentally. Our study defines the developmental block of MRT and reveals potential differentiation therapies

Organoid-based drug screening reveals neddylation as therapeutic target for malignant rhabdoid tumors

Malignant rhabdoid tumors (MRTs) represent one of the most aggressive childhood malignancies. No effective treatment options are available, and prognosis is, therefore, dismal. Previous studies have demonstrated that tumor organoids capture the heterogeneity of patient tumors and can be used to predict patient response to therapy. Here, we perform drug screening on patient-derived normal and tumor organoids to identify MRT-specific therapeutic vulnerabilities. We identify neddylation inhibitor MLN4924 as a potential therapeutic agent. Mechanistically, we find increased neddylation in MRT organoids and tissues and show that MLN4924 induces a cytotoxic response via upregulation of the unfolded protein response. Lastly, we demonstrate in vivo efficacy in an MRT PDX mouse model, in which single-agent MLN4924 treatment significantly extends survival. Our study demonstrates that organoids can be used to find drugs selectively targeting tumor cells while leaving healthy cells unharmed and proposes neddylation inhibition as a therapeutic strategy in MRT

Organoid-based drug screening reveals neddylation as therapeutic target for malignant rhabdoid tumors

Malignant rhabdoid tumors (MRTs) represent one of the most aggressive childhood malignancies. No effective treatment options are available, and prognosis is, therefore, dismal. Previous studies have demonstrated that tumor organoids capture the heterogeneity of patient tumors and can be used to predict patient response to therapy. Here, we perform drug screening on patient-derived normal and tumor organoids to identify MRT-specific therapeutic vulnerabilities. We identify neddylation inhibitor MLN4924 as a potential therapeutic agent. Mechanistically, we find increased neddylation in MRT organoids and tissues and show that MLN4924 induces a cytotoxic response via upregulation of the unfolded protein response. Lastly, we demonstrate in vivo efficacy in an MRT PDX mouse model, in which single-agent MLN4924 treatment significantly extends survival. Our study demonstrates that organoids can be used to find drugs selectively targeting tumor cells while leaving healthy cells unharmed and proposes neddylation inhibition as a therapeutic strategy in MRT