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Browsing ESS - TBIO - Artigos by Author "Almeida, Cátia"
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- Exploring the potential protective effect of probiotics in obesity-induced colorectal cancer: What insights can in vitro models provide?Publication . Viana, Rejane; Rocha, Ana C.; Sousa, André P.; Ferreira, Diogo; Fernandes, Rúben; Almeida, Cátia; Pais, Patrick J.; Baylina, Pilar; Pereira, Ana CláudiaColorectal cancer (CRC) is the third most common cancer diagnosed today and the third leading cause of death among cancer types. CRC is one of the gastrointestinal tumors with obesity as the main extrinsic risk factor, since, according to authors, the meta-inflammation sustained by the excess adipose tissue can provide abundant circulating lipids, as well as hormones and metabolites crucial to tumor development and aggressiveness. The gut microbiota can protect the colon from metainflammation and endocrine changes caused by obesity. The present study aimed to investigate the antitumor activity of a commercial probiotic in intestinal tumor cells under two adiposity conditions. Experimental assays were performed on the Caco2 cell line (colon adenocarcinoma) supplemented with differentiated adipocyte’s secretomes of the 3T3-L1 cell line (mouse pre-adipocytes) in two adiposity conditions: (i) differentiation without the use of Pioglitazone (noPGZ) and (ii) differentiation using Pioglitazone (PGZ). The Caco2 cells were first exposed to both secretomes for 24 h and evaluated and subsequently exposed to probiotic extract followed by secretome and evaluated. The effects of these treatments were evaluated using cytotoxicity assays by MTT, cell migration by injury, and antioxidant activity by glutathione assay. The use of secretomes showed a statistically significant increase in cell viability in Caco2 cells, either in noPGZ (p < 0.01) or PGZ (p < 0.05), and the probiotic was not able to reduce this effect. In the injury assay, secretome increased cell migration by more than 199% in both adiposity conditions (p < 0.001 in noPGZ and p < 0.01 in PGZ). In the probiotic treatment, there was a reduction in cell migration compared to the control in adiposity conditions. The antioxidant response of Caco2 cells was increased in both adiposity conditions previously exposed to the probiotic supernatant. This pilot work brings to light some findings that may answer why the modulation of the intestinal microbiota using probiotics is an alternative strategy leading to improvements in the condition and stage of the colon tumor. Additional studies are needed to clarify the role of Pioglitazone in this type of tumor and the metabolites of obesity that are attenuated by the use of probiotics.
- Harvesting the power of green synthesis: gold nanoparticles tailored for prostate cancer therapyPublication . Oliveira, Marco; Sousa, André; Sá, Sara; Soares, Sílvia; Pereira, Ana Cláudia; Rocha, Ana Catarina; Pais, Patrick; Ferreira, Diogo; Almeida, Cátia; Luís, Carla; Lima, Cláudio; Almeida, Fábio; Gestoso, Álvaro; Duarte, Miguel-Correa; Barata, Pedro; Martins-Mendes, Daniela; Baylina, Pilar; Pereira, Carla F.; Fernandes, RúbenBiosynthetic gold nanoparticles (bAuNPs) present a promising avenue for enhancing biocompatibility and offering an economically and environmentally responsible alternative to traditional production methods, achieved through a reduction in the use of hazardous chemicals. While the potential of bAuNPs as anticancer agents has been explored, there is a limited body of research focusing on the crucial physicochemical conditions influencing bAuNP production. In this study, we aim to identify the optimal growth phase of Pseudomonas aeruginosa cultures that maximizes the redox potential and coordinates the formation of bAuNPs with increased efficiency. The investigation employs 2,6-dichlorophenolindophenol (DCIP) as a redox indicator. Simultaneously, we explore the impact of temperature, pH, and incubation duration on the biosynthesis of bAuNPs, with a specific emphasis on their potential application as antitumor agents. Characterization of the resulting bAuNPs is conducted using ATR-FT-IR, TEM, and UV-Vis spectroscopy. To gain insights into the anticancer potential of bAuNPs, an experimental model is employed, utilizing both non-neoplastic (HPEpiC) and neoplastic (PC3) epithelial cell lines. Notably, P. aeruginosa cultures at 9 h/OD600 = 1, combined with biosynthesis at pH 9.0 for 24 h at 58 ◦C, produce bAuNPs that exhibit smaller, more spherical, and less aggregated characteristics. Crucially, these nanoparticles demonstrate negligible effects on HPEpiC cells while significantly impacting PC3 cells, resulting in reduced viability, migration, and lower IL-6 levels. This research lays the groundwork for the development of more specialized, economical, and ecologically friendly treatment modalities.
- Moving towards personalized medicine—The broad use of aptamers for targeted theranosticPublication . Sousa, André P.; Rocha, Ana C.; Almeida, Cátia; Carneiro, Mariana C. C. G.; Pais, Patrick P.; Viana, Rejane; Fernandes, Rúben; Barata, Pedro; Gestoso, Álvaro; Ramalho, Susana; Martins-Mendes, Daniela; Baylina, Pilar; Pereira, Ana CláudiaAptamers are short, single-stranded oligonucleotides synthesized in vitro from a randomized oligonucleotide library against a specific target. These molecules are capable of binding to a wide range of biological targets with high specificity and affinity. They present great advantages over antibodies with potential applications in research, diagnosis, and therapeutics. Specifically for tumors with late-stage identification and poor prognosis, like pancreatic cancer, the study of novel aptamers holds tremendous potential for cancer diagnosis and treatment. Along with cancer treatment, aptamers have also shown high potential in regulating the immune response and modulating several critical steps of signaling cascades, such as in immune checkpoints. In the context of microbiota and infection, aptamers are being studied to identify microbes and their metabolites. This assessment has the potential to improve the detection and management of infectious diseases while assisting us in better understanding health risks and treatment outcomes by tracking changes in the microbiota. In this review, the potential of aptamers is explored regarding their applications in cancer, immune, and microbiota therapy.