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Avaliação de complexos metálicos de Cobre (Cu(II)) e de Platina (Pt(II)) como agentes antiproliferativos em células tumorais
Publication . Marques, Cristiana de Jesus Rodrigues; Fernandes, Maria Alexandra
O cancro é uma doença complexa e devastadora que afeta milhões de pessoas em todo o mundo, caracterizada pelo crescimento descontrolado de células anormais no organismo. A quimioterapia é um dos tratamentos mais comuns para o cancro, consistindo na administração de agentes químicos que visam destruir as células cancerígenas ou inibir o seu crescimento.
Dentro dos agentes químicos, os complexos metálicos têm despertado o interesse na investigação médica, pois mostram elevado potencial como agentes quimioterapêuticos eficazes, devido às suas propriedades únicas que permitem a combinação com diversos ligandos existindo uma maior seletividade no ataque às células malignas, minimizando o impacto nas células saudáveis. Este avanço representa uma promissora perspetiva para o tratamento do cancro, em busca de alternativas mais eficazes, menos tóxicas e que evitem o aparecimento de resistências.
Neste trabalho, vários complexos de cobre (Cu(II)) e de platina (Pt(II)) foram testados em termos de atividade antiproliferativa em culturas 2D de carcinoma colorretal, carcinoma colorretal resistente à doxorrubicina, carcinoma do ovário e em fibroblastos primários humanos.
Entre os complexos testados, os complexos Cu1a, Cu1b e Pt1a mostram-se como os mais promissores com maiores índices de seletividade para as células de carcinoma de colorretal resistente à doxorrubicina (HCT116doxR; IC50 de 0,239, 0,290 e 0,683 respetivamente). Os resultados revelam que estes complexos são capazes de internalizar nas células HCT116doxR ao fim de 3h levando à formação de ROS com consequente alteração do potencial de membrana mitocondrial e indução de morte celular programada pela via apoptótica intrínseca e por autofagia. Estes complexos interferem ainda na progressão do ciclo celular com formação de células senescentes, conseguem clivar o DNA plasmídico através de mecanismos oxidativos e interagir com a albumina sérica bovina (BSA). Verificou-se ainda que os três complexos atrasam o processo de migração celular, mas apenas o complexo Pt1a parece ter algum efeito na retardação da neovascularização.
Breaking the mold
Publication . Cordeiro, Sandra; Oliveira, Beatriz B.; Valente, Ruben; Ferreira, Daniela; Luz, André; Baptista, Pedro V.; Fernandes, Alexandra R.; DCV - Departamento de Ciências da Vida; UCIBIO - Applied Molecular Biosciences Unit; Frontiers Media
Despite extensive efforts to unravel tumor behavior and develop anticancer therapies, most treatments fail when advanced to clinical trials. The main challenge in cancer research has been the absence of predictive cancer models, accurately mimicking the tumoral processes and response to treatments. The tumor microenvironment (TME) shows several human-specific physical and chemical properties, which cannot be fully recapitulated by the conventional 2D cell cultures or the in vivo animal models. These limitations have driven the development of novel in vitro cancer models, that get one step closer to the typical features of in vivo systems while showing better species relevance. This review introduces the main considerations required for developing and exploiting tumor spheroids and organoids as cancer models. We also detailed their applications in drug screening and personalized medicine. Further, we show the transition of these models into novel microfluidic platforms, for improved control over physiological parameters and high-throughput screening. 3D culture models have provided key insights into tumor biology, more closely resembling the in vivo TME and tumor characteristics, while enabling the development of more reliable and precise anticancer therapies.
Simplified Chip Prototyping for Improved Screening of Gene-silencing Therapeutics Using 3D Cell Models
Publication . Oliveira, Ana Beatriz Brito de; Baptista, Pedro
Cancer research has long been hindered by the limitations of conventional 2D culture models, which
fail to replicate the intricacies of the tumor microenvironment. This lack of complexity prevents accurate
evaluation of cancer therapeutics, including gene-silencing approaches. The shortcomings of standard
cancer models in recapitulating the dynamic microenvironment of tumors prompted the development of
more physiologically relevant models. While Tumor-on-Chip systems show promise in addressing these
challenges, their widespread adoption is limited due to technical complexity and high fabrication costs.
To overcome these barriers, this thesis presents a strategy to simplify the prototyping of ToC devices by
focusing on accessible materials and fabrication processes. This work outlines a pathway to create
efficient, reproducible, and cost-effective biochips suitable for cancer modeling and screening gene-
silencing therapeutics. The objectives include synthesizing and characterizing gold nanoparticle
conjugates, evaluating their gene silencing efficiency in 2D and 3D models, streamlining the biochip
fabrication, and translating these findings to the final device.
The results provided insights into the differential behavior of nanoparticle uptake and resultant silencing
efficiency between models. While 2D cultures exhibit faster uptake kinetics, 3D spheroids better mimic
diffusional barriers and tumor heterogeneity, making them a more reliable model for evaluating
nanoparticle-based therapies. The developed ToC device successfully reproduced these complexities,
yielding promising results. Still, future work should aim to incorporate fluidic channels and immune
cells to further enhance tumor microenvironment recapitulation, bridging the gap between preclinical
models and in vivo complexity to improve therapeutic predictions.
Mild hyperthermia via gold nanoparticles and visible light irradiation for enhanced siRNA and ASO delivery in 2D and 3D tumour spheroids
Publication . Ferreira, Daniela; Fernandes, Alexandra R.; Baptista, Pedro V.; DCV - Departamento de Ciências da Vida; UCIBIO - Applied Molecular Biosciences Unit; BioMed Central (BMC)
Background: The delivery of therapeutic nucleic acids, such as small interfering RNA (siRNA) and antisense oligonucleotides (ASO) into cells, is widely used in gene therapy. Gold nanoparticles (AuNPs) have proved to be effective in delivering silencing moieties with high efficacy. Moreover, AuNPs offer the possibility of spatial–temporal triggering of cell uptake through light irradiation due to their unique optical properties. Our study focuses on the use of AuNPs as improved vectorisation agents through mild photothermy triggered by visible light irradiation. This method promotes the transfection of oligonucleotides for gene silencing in 2D cells and more complex 3D spheroids. Results: Improving gene silencing strategies in 3D cell cultures is crucial since it provides more effective in vitro models to study cellular responses that closely resemble the in vivo tumour microenvironment. We demonstrate the potential of mild photothermy by effectively silencing the GFP gene in 2D cell cultures: HCT116 and MCF-7. Then we showed that mild photothermy could be effectively used for silencing the c-MYC oncogene transcript, which is greatly overexpressed in cancer cells. A decrease of 25% and 30% in c-MYC expression was observed in HCT116 2D cells and 7-day 3D spheroids, respectively. Conclusions: In summary, our findings offer a novel transfection approach for gene therapy applications in 2D and 3D tumour models. This approach is based on the use of mild photothermy mediated by AuNPs combined with visible laser irradiation that might pave the way for the spatial–temporal control of gene modulation.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
Concurso de Projetos de I&D em Todos os Domínios Científicos - 2022
Número da atribuição
2022.04315.PTDC