Browsing by Author "Soares, Raquel"
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- 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.
- Angiogenesis in Schistosoma haematobium-associated urinary bladder cancerPublication . Dematei, Anderson; Fernandes, Rúben; Soares, Raquel; Alves, Helena; Richter, Joachim; Botelho, Monica C.Schistosoma haematobium, a parasitic flatworm that infects more than 100 million people, mostly in the developing world, is the causative agent of urogenital schistosomiasis, and is associated with a high incidence of squamous cell carcinoma (SCC) of the bladder. During infection, eggs are deposited in the bladder causing an intense inflammatory reaction. Angiogenesis is defined as the formation of new blood vessels from preexisting ones and is recognized as a key event in cell proliferation and carcinogenesis and spread of malignant lesions. A growing amount of evidence points to angiogenesis playing a key role in schistosomiasis-associated bladder cancer. Thus, identifying biomarkers of this process plays an important role in the study of cancer. Here, we review recent findings on the role of angiogenesis in bladder cancer and the growth factors that induce and assist in their development, particularly SCC of the bladder associated to urogenital schistosomiasis.
- Anti-Angiogenic Properties of Cafestol and Kahweol Palmitate Diterpene EstersPublication . Moeenfard, Marzieh; Cortez, Alice; Machado, Vera; Costa, Raquel; Luís, Carla; Coelho, Pedro; Soares, Raquel; Alves, Arminda; Borges, Nuno; Santos, AlejandroEpidemiological studies support the association of coffee-specific diterpenes, with various beneficial health effects. Although anti-antiangiogenic properties of free cafestol and kahweol have been recently described, available data regarding their esterified form, in particular palmitate esters as the main diterpene esters present in coffee, are still rare. Given that angiogenesis plays an important role in many pathological conditions, including cancer growth and metastasis, this study aimed to assess and compare the potential anti-angiogenic effects of cafestol palmitate (CP) and kahweol palmitate (KP) in an in vitro angiogenesis model. According to our findings, both compounds inhibited angiogenesis steps on human microvascular endothelial cells (HMVECs), although a more significant effect was observed for KP. Compared to control, HMVECs viability decreased in a dose-dependent manner upon incubation either with CP or KP. Concentrations of 75 and 100 μM of each compound were cytotoxic. Cell proliferation was also dramatically reduced by both diterpene esters at 50 μM, although KP had a stronger inhibitory effect. However, CP and KP did not induce apoptosis on HMVECs. Both compounds reduced cell migration, but this effect was only statistically significant after KP incubation. Inhibition of VEGFR2 expression and its downstream effector Akt, but not Erk, was also observed in CP- and KP-treated HMVECs. These findings were confirmed using ELISA assay for phosphorylated (active) VEGFR-2. Taken together, these data indicate that both CP and KP can be considered potent compounds against angiogenesis-dependent disorders. Our findings further indicate that KP exerts more potent anti-angiogenic effects than CP, in most of assays.
- Avoiding the interference of doxorubicin with MTT measurements on the MCF-7 breast cancer cell linePublication . Luís, Carla; Castaño-Guerrero, Yuselis; Soares, Raquel; Sales, Goreti; Fernandes, RúbenDoxorubicin (DOXO) is an adjuvant chemotherapy agent and is also commonly used in cell biology research. Cytotoxic assays in cell culture are frequently used in order to stablish drug concentrations that are useful for controlling cell proliferation. One common cytotoxic method used is 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT). Our present research aims to support future studies in engaging MTT assay using DOXO that exhibits a strong red coloration and fluorescence, and so it is assumed that DOXO may interfere with commonly used colorimetric assays such as MTT. The interference of DOXO in the MTT determination was evaluated in a Breast Cancer cell line Michigan Cancer Foundation-7 (MCF-7). The interference was evaluated by means of spectroscopic methods in particular spectrophometry and fluorescence spectroscopy of MTT and DOXO. We postulate that the medium and the MTT reagent itself can interfere on the metabolic activity method, so in order to achieve better results, DMEM was replaced by a neutral buffer like Phosphate-buffered saline (PBS). This protocol may be extremely useful in future studies involving DOXO.
- 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.
- 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.
- Estrogen Metabolism-Associated CYP2D6 and IL6-174G/C Polymorphisms in Schistosoma haematobium InfectionPublication . Cardoso, Rita; Lacerda, Pedro; Costa, Paulo; Machado, Ana; Carvalho, André; Bordalo, Adriano; Fernandes, Rúben; Soares, Raquel; Richter, Joachim; Alves, Helena; Botelho, MonicaSchistosoma haematobium is a human blood fluke causing a chronic infection called urogenital schistosomiasis. Squamous cell carcinoma of the urinary bladder (SCC) constitutes chronic sequelae of this infection, and S. haematobium infection is accounted as a risk factor for this type of cancer. This infection is considered a neglected tropical disease and is endemic in numerous countries in Africa and the Middle East. Schistosome eggs produce catechol-estrogens. These estrogenic molecules are metabolized to active quinones that induce modifications in DNA. The cytochrome P450 (CYP) enzymes are a superfamily of mono-oxygenases involved in estrogen biosynthesis and metabolism, the generation of DNA damaging procarcinogens, and the response to anti-estrogen therapies. IL6 Interleukin-6 (IL-6) is a pleiotropic cytokine expressed in various tissues. This cytokine is largely expressed in the female urogenital tract as well as reproductive organs. Very high or very low levels of IL-6 are associated with estrogen metabolism imbalance. In the present study, we investigated the polymorphic variants in the CYP2D6 gene and the C-174G promoter polymorphism of the IL-6 gene on S. haematobium-infected children patients from Guine Bissau. CYP2D6 inactivated alleles (28.5%) and IL6G-174C (13.3%) variants were frequent in S. haematobium-infected patients when compared to previously studied healthy populations (4.5% and 0.05%, respectively). Here we discuss our recent findings on these polymorphisms and whether they can be predictive markers of schistosome infection and/or represent potential biomarkers for urogenital schistosomiasis associated bladder cancer and infertility.
- 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.
- Exploring the anti-cancer properties of pomegranate peel aqueous extractPublication . Luís, Carla; Sousa, André P.; Costa, Raquel; Maduro, Ana T.; Pais, Patrick J.; Sá, Sara; Gestoso, Álvaro; Fernandes, Flávia; Jerónimo, Eliana; Soares, Raquel; Fernandes, Rúben; Baylina, Pilar; Duarte, Maria F.The objective of this work is to evaluate the influence of pomegranate peel extract (PPE) in the behavior of breast cell lines (epithelial and tumor type) and related oxidative metabolism. Fruitbased functional foods have been the target of increasing scientific research for their physiological and pathophysiological properties. Pomegranate (Punica granatum) is a suitable example with both prophylactic and medicinal effects. MCF-7 cell line from tumor breast carcinoma, and MCF-10A cell line from normal epithelial mammary gland were used and subjected to different concentrations of PPE, ranging from 1 to 5 mM of gallic acid equivalents (GAE). Viability, proliferation, mobility, and cytotoxicity assays were performed along with the quantification of antioxidant enzymes, namely, catalase, superoxide dismutase (SOD) and reduced (GSH) and oxidized (GSSG) glutathione. We observed a decrease in viability and proliferation of MCF-7 cells, at higher concentrations of PPE, with no influence in epithelial cells. Interestingly, in a concentration-dependent manner, PPE triggered a significant decrease in migration on both cell lines, with a more pronounced effect in breast cancer cell line. Regarding antioxidant enzyme activity, on tumor cells higher concentrations of PPE decreased catalase activity and significantly increased SOD activity. Regarding GSH and GSSG, we observed different expression levels between MCF-7 and MCF-10A, with MCF-7 presenting lower levels compared to MCF-10A. GSH/GSSG ratio was notably higher in MCF-7 at 5 mM GAE. PPE exhibits anti-tumor effects without significantly affecting normal epithelial cells. Our work strengthens the potential antitumoral effect of PPE by reducing MCF-7 cell viability and proliferation through the imbalance of antioxidant enzymes.