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- Distúrbios alimentares – anorexia: da auto-imagem às atitudes e comportamentosPublication . Fernandes, Rúben; Reis, AC.; Esteves-Pinto, A.; Fonte, R.; Coelho, Pedro; Prudêncio, CristinaSão ainda escassos os estudos sobre distúrbios alimentares em alunos do ensino universitário em Portugal. Estudos mais recentes indicam que poderá existir uma predisposição genética para a anorexia, no entanto, os fatores ambientais são os que apresentam um papel determinante, em particular factores sócio-económicos, psicológicos, biológicos entre outros. Entre esses diversos factores, sabe-se que a auto-imagem pode relacionar-se como múltiplos distúrbios alimentares como a anorexia e bulimia.
- 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.
- A hiperglicemia e o secretoma de adipócitos alteram o padrão de crescimento de micobactérias in vitroPublication . Fernandes, Rúben; Bronze, M.; Pereira, C.; Coelho, Pedro; Prudêncio, Cristina
- 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.
- Adipocyte-released factors enhance melanocyte’s proliferation and motilityPublication . Fernandes, Rúben; Coelho, Pedro; Almeida, Joana; Prudêncio, Cristina; Soares, RaquelObesity, favored by the modern lifestyle, acquired epidemic proportions nowadays. Obesity has been associated with various major causes of death and morbidity including malignant neoplasms. Cutaneous melanoma incidence rates have also been increasing uring the last four decades in several countries. Obesity involvement in melanoma etiology has been recognized, but the implicated mechanisms remain unclear. We propose to address the above relationship and investigate the mechanism interplaying between obesity and an increased risk of melanoma onset.
- Differential imune response to vitamin A in B16-F10 malignant melanocytesPublication . Oliveira, S.; Coelho, Pedro; Costa, J.; Prudêncio, Cristina; Soares, R.; Guerreiro, S. G.; Fernandes, RúbenMelanoma is an aggressive form of skin cancer with a poor prognosis, due to its refractory behavior to radiation and chemotherapy. Although the diagnosis is straightforward, there are many disagreements regarding its treatment and surveillance. In order to surpass some of the limitations addressed to the treatment, preventive methods like antioxidant vitamins are nowadays a relevant field of research, as well as immunostimulation by external agents. Despite the knowledge about melanoma biology, pathogenesis and developed therapies, is important to understand the effect of vitamin A in order to suggest alternatives to conventional therapies, which are known to be ineffective against melanoma.
- Biomolecules in the relationship of cancer and obesityPublication . Almeida, Joana; Coelho, Pedro; Prudêncio, Cristina; Vieira, Mónica; Fernandes, Rúben; Fonseca, Magda; Soares, Raquel; Silva, Liliana; Faria, Isabel; Monteiro, Armanda; Pinto, Gabriela; Cea, V.; Galesio, M.; Noronha, J. P.; Diniz, M. S.; Sala, C.Obesity has been associated with various major causes of death and morbidity including malignant neoplasms. This increased prevalence has been accompanied by a worldwide increase in cutaneous melanoma incidence rates during the last decades, as well as gliomas, the most common primary malignant brain tumors in adults (Almeida et al., 2019). Although obesity aetiology is established, the implicated mechanisms remain unclear (Coelho et al., 2016). Melanoma is refractory to conventional therapies, and radiotherapy usage as an adjuvant therapy in cutaneous melanoma patients is ineffective, so it is extremely important to understand the antioxidant modulation of melanoma under an environment of obesity (Coelho et al., 2017; Oliveira et al., 2016). Moreover, the metastatic potential of some types of cancer is reduced or inhibited by obesity, which drives major concerns on the prognosis of metastasized patients (Fonseca et al., 2021). All of the studies disclose interesting models for the study of these tumors’ biology under an obese environment, that can be explored for the search of biomarkers, prognostic markers and therapeutic approaches.
- 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.
- Metabolic syndrome and inflammation: is there a microvascular and an incretin system impairment in the gastrointestinal tract?Publication . Costa, J.; Almeida, J.; Coelho, Pedro; Oliveira, S.; Prudêncio, Cristina; Soares, R.; Gomes-Guerreiro, S.; Fernandes, RúbenMetabolic syndrome is a multifactorial disorder characterized by increased plasma levels of glucose, cholesterol and triglycerides, but also overweight and obesity promoted by increase of body fat mass, alterations in oxidative stress, chronic low grade inflammation and resistance to insulin leading to risk of cardiovascular diseases. The stomach and the intestine have an essential role in metabolism with functions of digesting food and absorption of nutrients. Also, the intestine produces incretin hormones, such as GLP-1 which regulates glucose metabolism and processes of the gastrointestinal tract.
- Effect of Adipocyte Secretome in Melanoma Progression and Vasculogenic MimicryPublication . Coelho, Pedro; Almeida, Joana; Prudêncio, Cristina; Fernandes, Rúben; Soares, RaquelObesity, favored by the modern lifestyle, acquired epidemic proportions nowadays. Obesity has been associated with various major causes of death and morbidity including malignant neoplasms. This increased prevalence has been accompanied by a worldwide increase in cutaneous melanoma incidence rates during the last decades. Obesity involvement in melanoma aetiology has been recognized, but the implicated mechanisms remain unclear. In the present study, we address this relationship and investigate the influence of adipocytes secretome on B16-F10 and MeWo melanoma cell lines. Using the 3T3-L1 adipocyte cell line, as well as ex vivo subcutaneous (SAT) and visceral (VAT) adipose tissue conditioned medium, we were able to show that adipocyte-released factors play a dual role in increasing melanoma cell overall survival, both by enhancing proliferation and decreasing apoptosis. B16-F10 cell migration and cell-cell and cell-matrix adhesion capacity were predominantly enhanced in the presence of SAT and VAT released factors. Melanocytes morphology and melanin content were also altered by exposure to adipocyte conditioned medium disclosing a more dedifferentiated phenotype of melanocytes. In addition, exposure to adipocyte-secreted molecules induced melanocytes to rearrange, on 3D cultures, into vessel-like structures, and generate characteristic vasculogenic mimicry patterns. These findings are corroborated by the released factors profile of 3T3-L1, SAT, and VAT assessed by microarrays, and led us to highlight the mechanisms by which adipose secretome from sub-cutaneous or visceral depots promote melanoma progression.