Browsing by Author "Costa, Madalena"
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- Adipocyte Secreted Factors Enhance Aggressiveness of Prostate Carcinoma CellsPublication . Moreira, Ângela; Pereira, Sofia S.; Costa, Madalena; Morais, Tiago; Pinto, Ana; Fernandes, Rúben; Monteiro, Mariana P.Obesity has been associated with increased incidence and risk of mortality of prostate cancer. One of the proposed mechanisms underlying this risk association is the change in adipokines expression that could promote the development and progression of the prostate tumor cells. The main goal of this study was to evaluate the effect of preadipocyte and adipocyte secretome in the proliferation, migration and invasion of androgen independent prostate carcinoma cells (RM1) and to assess cell proliferation in the presence of the adiposity signals leptin and insulin. RM1 cells were co-cultured in with preadipocytes, adipocytes or cultured in their respective conditioned medium. Cell proliferation was assessed by flow cytometry and XTT viability test. Cell migration was evaluated using a wound healing injury assay of RM1 cells cultured with conditioned media. Cellular invasion of RM1 cells co-cultured with adipocytes and preadipocytes was assessed using matrigel membranes. Preadipocyte conditioned medium was associated with a small increase in RM1 proliferation, while adipocytes conditioned media significantly increased RM1 cell proliferation (p<0.01). Adipocytes also significantly increased the RM1 cells proliferation in co-culture (p <0.01). Cell migration was higher in RM1 cells cultured with preadipocyte and adipocyte conditioned medium. RM1 cell invasion was significantly increased after co-culture with preadipocytes and adipocytes (p <0.05). Insulin also increased significantly the cell proliferation in contrast to leptin, which showed no effect. In conclusion, prostate carcinoma cells seem to be influenced by factors secreted by adipocytes that are able to increase their ability to proliferate, migrate and invade.
- In vivo models in cancer researchPublication . Costa, Madalena; Quintela Vieira, Filipa; Silva, ReginaCancers figure among the leading causes of morbidity and mortality worldwide. Over the last decade there has been an extraordinary increase in our knowledge of the fundamental molecular processes that are involved in the development of cancer and its response to treatment. Studies in tissue culture have multiplied our acquaintance of cancer cell pathophysiology, mechanisms of transformation and strategies of survival of cancer cell lines, revealing therapeutically exploitable differences to normal cells. However, tumors are heterogeneous, structurally complex and result from an evolving crosstalk between different cell types and its surrounding tissue. A full elucidation of events occurring inside the cancer microenvironment is fundamental more effective therapies. Experiment in vivo models remains essential to understand the fundamental mechanisms underpinning malignancy and to discover improved methods to prevent, diagnose and treat cancer. This presentation will summarize currently available in vivo models of cancer, define the limitations and advantages of each modeling option and suggest the basis with which particular models should be used to answer a specific scientific question.
- A mouse model reproducing the pathophysiology of neonatal group B streptococcal infectionPublication . Bonifácio Andrade, Elva; Magalhães, Ana; Puga, Ana; Costa, Madalena; Bravo, Joana; Portugal, Camila Cabral; Ribeiro, Adília; Correia-Neves, Margarida; Faustino, Augusto; Firon, Arnaud; Trieu-Cuot, Patrick; Summavielle, Teresa; Ferreira, PaulaGroup B streptococcal (GBS) meningitis remains a devastating disease. The absence of an animal model reproducing the natural infectious process has limited our understanding of the disease and, consequently, delayed the development of effective treatments. We describe here a mouse model in which bacteria are transmitted to the offspring from vaginally colonised pregnant females, the natural route of infection. We show that GBS strain BM110, belonging to the CC17 clonal complex, is more virulent in this vertical transmission model than the isogenic mutant BM110∆cylE, which is deprived of hemolysin/cytolysin. Pups exposed to the more virulent strain exhibit higher mortality rates and lung inflammation than those exposed to the attenuated strain. Moreover, pups that survive to BM110 infection present neurological developmental disability, revealed by impaired learning performance and memory in adulthood. The use of this new mouse model, that reproduces key steps of GBS infection in newborns, will promote a better understanding of the physiopathology of GBS-induced meningitis.