ABSTRACT
Three-dimensional organoid culture technologies have revolutionized cancer research by allowing for more realistic and scalable reproductions of both tumour and microenvironmental structures1-3. This has enabled better modelling of low-complexity cancer cell behaviours that occur over relatively short periods of time4. However, available organoid systems do not capture the intricate evolutionary process of cancer development in terms of tissue architecture, cell diversity, homeostasis and lifespan. As a consequence, oncogenesis and tumour formation studies are not possible in vitro and instead require the extensive use of animal models, which provide limited spatiotemporal resolution of cellular dynamics and come at a considerable cost in terms of resources and animal lives. Here we developed topobiologically complex mini-colons that are able to undergo tumorigenesis ex vivo by integrating microfabrication, optogenetic and tissue engineering approaches. With this system, tumorigenic transformation can be spatiotemporally controlled by directing oncogenic activation through blue-light exposure, and emergent colon tumours can be tracked in real-time at the single-cell resolution for several weeks without breaking the culture. These induced mini-colons display rich intratumoural and intertumoural diversity and recapitulate key pathophysiological hallmarks displayed by colorectal tumours in vivo. By fine-tuning cell-intrinsic and cell-extrinsic parameters, mini-colons can be used to identify tumorigenic determinants and pharmacological opportunities. As a whole, our study paves the way for cancer initiation research outside living organisms.
Subject(s)
Cell Transformation, Neoplastic , Colon , Colorectal Neoplasms , Optogenetics , Organoids , Animals , Humans , Mice , Cell Transformation, Neoplastic/pathology , Cell Transformation, Neoplastic/radiation effects , Colon/pathology , Colon/radiation effects , Colorectal Neoplasms/etiology , Colorectal Neoplasms/pathology , Light , Optogenetics/methods , Organoids/pathology , Organoids/radiation effects , Single-Cell Analysis , Time Factors , Tissue Engineering/methods , Tumor Microenvironment , Drug Evaluation, PreclinicalABSTRACT
Abstract Purpose: To describe a new model of actinic enteritis that does not use radiotherapy machines. Methods: Sixteen Wistar rats were divided into four groups, consisting of four animals each: control (group A), two weeks after irradiation (group B), five weeks after irradiation (group C) and eight weeks after irradiation (group D). Animals were given a 10Gy radiation from a Cobalt-60 natural source in a nuclear technology research center. Protections of the surrounding tissues were obtained through the usage of plumb devices with a hole in the center, which served as a collimator. We obtained irradiated and non-irradiated colons from each animal. Results: In group B we found an important inflammatory response in the irradiated colon, which appeared in a reduced way in group C and was minimal in group D, in which we found a relevant collagen submucosal deposition/fibrosis. In all groups, the non-irradiated colon had a lower pathological damage in comparison with the irradiated colon. Conclusion: We thus described an efficient and feasible technique for obtaining an animal model of actinic enteritis.
Subject(s)
Animals , Female , Rats , Radiation Injuries, Experimental/pathology , Cobalt Radioisotopes , Colon/radiation effects , Dose-Response Relationship, Radiation , Rats, Wistar , Colon/pathology , Disease Models, AnimalABSTRACT
OBJETIVO: Avaliar as alterações estruturais na parede do cólon irradiado, em ratos, verificando se a suplementação de L-glutamina pode prevení-las. MÉTODOS: Foram empregados 30 ratos Wistar, machos, adultos, divididos em três grupos: I - controle, II- irradiado e III - irradiado, com suplementação de L-glutamina durante os 14 dias do estudo. O Grupo Controle foi mantido em condições-padrão de laboratório, enquanto os grupos II e III foram submetidos à irradiação abdominal, com dose única de 1000 cGy, no 8°. dia da experimentação. Todos os animais foram operados no 15°. dia, para ressecção de segmento colônico para análise estereológica. RESULTADOS: O grupo II apresentou volume total da parede colônica significativamente menor que o Grupo Controle, sem alterar os volumes parciais de cada camada histológica. No grupo III, houve manutenção do volume total da parede do cólon, próxima ao Grupo Controle, com aumento significativo da camada mucosa, quando comparada aos grupos I e II. Na camada mucosa do grupo III, houve a manutenção do volume parcial do epitélio, comparado ao Grupo Controle, sem melhora significativa da superfície epitelial. CONCLUSÃO: Sugere-se que a suplementação de L-glutamina seja benéfica na parede do cólon irradiado, em ratos.
Subject(s)
Animals , Male , Rats , Colon/radiation effects , Glutamine/therapeutic use , Radiation Injuries, Experimental/prevention & control , Abdominal Wall , Administration, Oral , Colon/drug effects , Colon/pathology , Intestinal Mucosa/drug effects , Intestinal Mucosa/pathology , Intestinal Mucosa/radiation effects , Organ Size/drug effects , Organ Size/radiation effects , Rats, Wistar , Radiation Injuries, Experimental/pathology , Statistics, Nonparametric , Time FactorsABSTRACT
Objetivo: Avaliar a ação da oxigenação hiperbárica em lesões actínicas provocadas por radiação ionizante no colo distal de ratas. Métodos: Foram utilizadas 32 ratas adultas distribuídas em quatro grupos. I - sham; II - oxigenoterapia hiperbárica (OHT); III - radioterapia (RT), e IV - radioterapia e oxigenoterapia hiperbárica (da mesma maneira que nos grupos II e III). Segmentos de colo distal foram fixados em formol a 10 por cento e processados para avaliação histológica e morfométrica. Resultados: Os resultados do experimento mostraram lesão das glândulas intestinais, vasodilatação e infiltrado leucocitário na lâmina própria e submucosa no colo dos animais pertencentes ao grupo RT que diminuiu acentudadamente após a oxigenioterapia hiperbárica. Conclusão: A oxigenitoterapia hiperbárica atenua as alterações morfológicas da mucosa e submucosa do cólon distal de ratas com enterite induzida por radiação ionizante.
Subject(s)
Animals , Female , Rats , Colon/radiation effects , Colon/injuries , Enteritis , Hyperbaric Oxygenation/methods , Radiation Effects , Radiation, Ionizing , Rats, WistarABSTRACT
La rectorragia es un síntoma frecuente en los pacientes con colitis por radiación crónica y se debe a lesiones vasculares mucosas usualmente confinadas al resto. Presentamos nuestra experiencia con el uso de la sonda caliente (HP), en 8 pacientes con colitis por radiación cuyo síntoma más importante fue la rectorragía. En 6 pacientes la indicación de la radioterapia fue cáncer de cuello uterno y en 2 casos cáncer de endometrio. Se realizaron de 1 a 4 sesiones de termocoagulación con una intensidad entre los 200 a 400 joules por sesión. En todos los pacientes se obtuvo una respuesta favorable con disminución o desaparición de los episodios de sangramiento y por lo tanto mejoría de las cifras hematológicas y de la necesidad del número de transfunsiones. Pensamos que la sonda caliente representa una excelente alternativa de tratamiento para estos pacientes de difícil manejo terapéutico