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- Potentional radiosensitizer effect of TUDCA in a obesity model of brain tumor cellsPublication . Silva, Liliana; Almeida, Joana; Coelho, Pedro; Faria, Isabel; Monteiro, Armanda; Soares, Raquel; Vieira, Mónica; Prudêncio, Cristina; Fernandes, RúbenObesity may play an important role in the biology of seve ral types of cancer, but the correlation with glioma Is still not very well defined. Former studies indicated that obesity may be related with an decreased resistance to radiation and increased redox status in brain tumors. Since radiothetapy is the most commonly treatment modality used in this type of tumor, we creale a new model of experiments to determinate the influence of obesity in glioma cells [n the presence of radiation with an imbalance of redox status, BC3H1 glioma cells were treated with t-BOOH (150~M), TUDCA (25~M) and a mix of t-BOOH and TUOCA{150~M and 25~M respectively) in serum-free OMEM or conditioned media (CM) from differentiated 3T3-L 1 adj pocytes. Afterwards the cells were irradiated with a total dose of 2 Gy. Subsequently BC3H1 viability was evaluated, by MTT assay, after 4 and 12 hours. We observed an increase in viability In all cells treated solely with 3T3-L 1 eM. Interestingly, in the presence of CM plus TUDCA or t-BOOH, the viability of 6C3H1 was inferior of TUOCA or t~BOOH treatments alone, this effect was independent of irradia tion. After 12 hours the I/iability of the glioma cells was significantly higher on irradiated ceUs treated only with eM, this effect was not yet observed at the 4 hours time point But, in the presence of mix of t~BOOH and TUDCA, with eM and irradiation the cells viability decrea se significanUy. The 3T3-L 1 Me increase (he cell viabrlity in the presence of radiation or not, after 12 hours expose" But in the presence of oxidatIve inducer and, In specially, with the antioxidant TUDCA, the BC3Hi viability significantly decrease. So, we observed a potential radiosensitfzer effect of TUDCA in BC3H1 in the presence of 3T3-L1 adipocytes.
- Adipocyte secretome increases radioresistance of malignant melanocytes by improving cell survival and decreasing oxidative statusPublication . Coelho, Pedro; Silva, Liliana; Faria, Isabel; Vieira, Mónica; Monteiro, Armanda; Pinto, Gabriela; Prudêncio, Cristina; Fernandes, Rúben; Soares, RaquelRadiotherapy is a treatment option for the majority of malignancies. However, because melanoma is known to be radioresistant, the use of ionizing radiation as an adjuvant therapy in cutaneous melanoma patients is ineffective. Obesity has now been recognized as a risk factor for melanoma. High adiposity is generally associated with a more pro-oxidative status. Oxidative stress is a major player in radiation therapy and also a common link between obesity and cancer. Several adipocyte-released proteins are known to have a role in controlling cellular growth and pro-survival signaling. For that reason, we investigated the influence of 3T3-L1 mature adipocyte secretome in B16-F10 malignant melanocyte radiosensitivity. We evaluated B16-F10 cell survival and redox homeostasis when exposed to four daily doses of ionizing radiation (2 Gy per day) up to a total of 8 Gy in a medical linear accelerator. B16-F10 melanocytes exhibited slight alterations in survival, catalase activity, nitrative stress and total oxidant concentration after the first 2 Gy irradiation. The motility of the melanocytes was also delayed by ionizing radiation. Subsequent irradiations of the malignant melanocytes led to more prominent reductions in overall survival. Remarkably, 3T3-L1 adipocyte-secreted molecules were able to increase the viability and migration of melanocytes, as well as lessen the pro-oxidant burden induced by both the single and cumulative X-ray doses. In vitro adipocyte-released factors protected B16-F10 malignant melanocytes from both oxidative stress and loss of viability triggered by radiation, enhancing the radioresistant phenoyype of these cells with a concomitant activation of the AKT signaling pathway These results both help to elucidate how obesity influences melanoma radioresistance and support the usage of conventional medical linear accelerators as a valid model for the in vitro radiobiological study of tumor cell lines.
- Book of abstracts 4th Meeting on Medicinal Biotechnology (4EBtM)Publication . Costa, Ana Rita; Dias, Ana Rita; Prudêncio, Cristina; Borges, Cristina; Teixeira, Dulce; Almeida, Joana; Vieira, Mónica; Coelho, Pedro; Ferraz, Ricardo; Cunha, SofiaThese meetings have been held once a year since 2015 and have played an important role as a point of contact among several professionals and students in Medicinal Biotechnology. Like the Medicinal Biotechnology field itself, these meetings have also been expanding, not only in the number of participants, but also in their geographical origin. Therefore, it is our goal to act as an interface between students and biotechnology companies/researchers, as well as to increasingly promote networking, projects and collaborations within this field for the upcoming years.
- Development of a chromatographic method for simultaneous analysis of glutathione formsPublication . Teixeira, Dulce; Coelho, Pedro; Prudêncio, Cristina; Azenha, Manuel; Vieira, MónicaReduced glutathione (GSH)is the most abundant low molecular weight thiol-containing tripeptide (glycine, cysteine, and glutamate) which is synthesized in the cells. GSHplays critical roles in protecting cells from oxidative damage and the toxicity of xenobiotics. Besides, it is also involved in the regulation of intracellular redox homeostasis, which leads to its oxidation into oxidized glutathione (GSSG). Determining the ratio of GSH/GSSG in different biological samples is a major procedure for the evaluation of an individual’s oxidative status and can be a potential biomarker of oxidative stress.
- Quinoxaline-1, 4-dioxide derivatives inhibitory action in melanoma and brain tumor cellsPublication . Silva, Liliana; Coelho, Pedro; Soares, Raquel; Prudêncio, Cristina; Vieira, MónicaQuinoxaline-1,4-dioxide derivatives are synthetic heterocyclic compounds with multiple biological and pharmacological effects. In this study, we investigated the bioactivity of five quinoxaline-1,4-di-N-oxides derivatives in different animal cell lines.
- Book of abstracts of the III Encontro de Biotecnologia Medicinal/ I Iberian Congress on Medicinal BiotechnologyPublication . Costa, Ana Rita; Prudêncio, Cristina; Teixeira, Dulce; Almeida, Joana; Vieira, Mónica; Coelho, Pedro; Ferraz, Ricardo; Cunha, Sofia; Dias, Ana RitaEstes encontros de Biotecnologia Medicinal iniciaram-se em 2015 e sentimos que estamos a crescer, tal como a Biotecnologia Medicinal. Esta área da Biotecnologia tem ganho relevância, quer em empresas, quer a nível académico, criando interfaces entre a biologia molecular, a microbiologia e a química medicinal.
- Melanoma and obesity: Should antioxidant vitamins be addressed?Publication . Oliveira, Sofia; Coelho, Pedro; Prudêncio, Cristina; Vieira, Mónica; Soares, Raquel; Guerreiro, Susana G.; Fernandes, RúbenMelanoma is an aggressive form of skin cancer refractory to conventional therapies. Obesity has reached epidemic dimensions acting as a risk factor for several cancer types, such as melanoma. Several reactive species of oxygen are also involved in melanoma initiation and progression. Low levels of antioxidant content and/or activity in lightly pigmented cells could expose them to an extremely oxidative environment and rise the susceptibility to oxidative damage and consequently loss of cell homeostasis. Despite the knowledge about melanoma biology, pathogenesis and developed therapies, is extremely important to understand the antioxidant modulation of melanoma under an environment of obesity, especially the effect of some natural compounds of the diet, such as antioxidant vitamins A, C and E and selenium in order to establish alternatives to conventional therapies, which are known to be ineffective against melanoma.
- Evaluation of quinoxaline-1,4-dioxide and derivatives biological activity in normal and tumour cellPublication . Silva, Liliana; Coelho, Pedro; Soares, Raquel; Prudêncio, Cristina; Vieira, MónicaQuinoxaline derivatives are synthetic heterocyclic compounds with multiples pharmacological applications and biological effects. Previous studies of our group about the biological activity in eukaryotic and prokaryotic microbial models with quinoxaline-1,4-dioxide (QNX) derivatives concluded a selective antimicrobial activity in gram negative strains. To further evaluate these compounds’ potential, we investigated the biologic activity in vitro of this chemical structures in normal and tumour cells lines.
- ß-lactamases in the biochemistry and molecular biology laboratoryPublication . Amador, Paula; Prudêncio, Cristina; Vieira, Mónica; Ferraz, Ricardo; Fonte, Rosália; Silva, Nuno; Coelho, Pedro; Fernandes, Rúbenβ-lactamases are hydrolytic enzymes that inactivate the β-lactam ring of antibiotics such as penicillins and cephalosporins. The major diversity of studies carried out until now have mainly focused on the characterization of β-lactamases recovered among clinical isolates of Gram-positive staphylococci and Gram-negative enterobacteria, amongst others. However, only some studies refer to the detection and development of β-lactamases carriers in healthy humans, sick animals, or even in strains isolated from environmental stocks such as food, water, or soils. Considering this, we proposed a 10-week laboratory programme for the Biochemistry and Molecular Biology laboratory for majors in the health, environmental, and agronomical sciences. During those weeks, students would be dealing with some basic techniques such as DNA extraction, bacterial transformation, polymerase chain reaction (PCR), gel electrophoresis, and the use of several bioinformatics tools. These laboratory exercises would be conducted as a mini research project in which all the classes would be connected with the previous ones. This curriculum was compared in an experiment involving two groups of students from two different majors. The new curriculum, with classes linked together as a mini research project, was taught to a major in Pharmacy and an old curriculum was taught to students from environmental health. The results showed that students who were enrolled in the new curriculum obtained better results in the final exam than the students who were enrolled in the former curriculum. Likewise, these students were found to be more enthusiastic during the laboratory classes than those from the former curriculum.
- Extended-spectrum β-lactamases from the North of Portugal in the boundaries to Spain: emergence of high resistance to 4th generation cephalosporinsPublication . Fernandes, Rúben; Ferraz, Ricardo; Vieira, Mónica; Amador, Paula; Brito, Luísa; Coelho, Pedro; Silva, Nuno; Oliveira, C.; Prudêncio, CristinaDuring the past 15 years, emergence and dissemination of third-generation cephalosporins resistance in nosocomial Enterobacteriaceae became a serious problem worldwide, due to the production of extended-spectrum-β-lactamases (ESBLs). The aim of this study was to investigate among the presence of ESBL-producing enterobacteria among Portuguese clinical isolates nearby Spain, to investigate the antimicrobial susceptibility patterns and to compare the two countries. The β-lactamases genes, blaTEM, blaSHV and blaCTX-M were detected by molecular methods. Among the ESBL-producing isolates it was found extraordinary levels (98.9%) of resistance to the fourth-generation cephalosporin Cefepime. These findings point to the need of reevaluate the definition of ESBL.