ESS - CIIMAR@E2S - Comunicações em eventos científicos
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- Cytotoxicity of marine cyanobacteria extracts on osteosarcoma cellsPublication . Costa-Rodrigues, João; Costa, M. M.; Costa, S.; Garcia, M.; Fernandes, M. H.; Vasconcelos, V.; Barros, Piedade; Martins, RosárioMarine cyanobacteria have been identified as a rich source of secondary metabolites with potential pharmacological applications. Anti-inflammatory, antibacterial and anticancer activities are some examples of properties described for cyanobacteria compounds, being the cytoxicity against cancer cell lines one of the most documented. The Laboratory of Ecotoxicology Genomics and Evolution (LEGE) — CIIMAR, Porto, Portugal, possesses a large collection of cyanobacteria strains isolated from the Portuguese coast. In order to investigate the interest of genera such as Cyanobium, Synechocystis, Synechococcus, Leptolyngbya and Pseudoanabaena which are genera that have been largely overlooked in terms of bioactivity, we have been screening their ability to induce cytotoxicity on human cancer cell lines. Assays have been conducted with a crude extract obtained by a dichloromethane and methanol extraction of freeze dried biomass and three fractions obtained using Si column chromatography with a gradient from 100% hexane, to 100% ethyl acetate to 100% methanol. The cytotoxicity of cyanobacteria crude extract and fractions has been evaluated by the MTT assay at 24, 48 and 72 h. Here we present the results concerning the cytotoxicity of 24 cyanobacteria strains on the osteosarcoma cell line MG63. The results show both inhibitory and stimulatory effects on cell growth within the same cyanobacteria strain. However, five cyanobacteria strains were found to induce a decrease in cell viability that reached the 80% within the ethyl acetate fraction, which makes this fraction interesting for the isolation and characterization of new bioactive compounds.
- Elucidating the mechanisms Involved in the cytotoxicity induced by marine cyanobacteria strains against the RKO colon carcinoma cell linePublication . Freitas, S.; Urbatzka, R.; Osório, H.; Costa, M.; Barros, Piedade; Vasconcelos, V.; Martins, RosárioCyanobacteria are known to synthesize secondary metabolites that may have potential as drugs for the treatment of human diseases such as cancer. Previous studies on marine cyanobacteria isolated from the Portuguese coast revealed strains of the picoplanktonic genera Cyanobium and Synechocystis as potential sources of anticancer compounds. The ethyl acetate fraction of the strains Cyanobium sp. LEGE06113 and the Synechocystis salina LEGE06155 was found to reduce cell viability of cancer cell lines. This work aimed to elucidate the mechanisms involved in the cytotoxicity of this strains in the colon adenocarcinoma cell line RKO by employing real-time PCR (RT-PCR) for genes involved in cell cycle and apoptosis, by flow cytometry for cell cycle and by two-dimensional gel electrophoresis for protein expression. RT-PCR results revealed differences in mRNA expression of genes CCNB1 (cell cycle) and BCL-2 (apoptosis). Flow cytometry results revealed a decrease in the G0/G1 and S phase and increased its number in the G2/M phase, which is in accordance with the lower expression of CCNB1. The proteomic results demonstrated different protein patterns comparing treatment groups with control. Proteins differentially regulated in exposed RKO cells were involved in cell cycle regulation, apoptosis, cell structure, protein regulation and cell metabolism. Although several of these proteins were identified in cells exposed to both cyanobacterial extracts, the data provides an indication that the cytotoxicity is induced by different toxic mechanisms in LEGE06113 and LEGE06155 fractions.
- Evaluating the effect of the Ionic liquid [C16Pyr] [Amp] in hormone-resistant tumors using an in vivo zebrafish assayPublication . Barros, Piedade; Martins, Rosário; Cruz, Agostinho; Silva, ReginaThe NASYTHOR project, aimes to study the potential of novel natural and synthetic compounds as anti-cancer drugs on hormone-resistant tumors. One of the objectives is the evaluation of the in vivo efficacy of the anticancer activity of the compounds using Danio rerio, zebrafish embryo as a model. In this work we describe the general methodology, advantages and disadvantages. Among a large range of advantages in the use of zebrafish in cancer research, the high level of genetic and physiologic homology with humans, including brain, digestive tract, musculature and vasculature can be highlighted. Also, the immature immune system of the embryos favors xenotransplantation of human cancer cells, and makes these animals a promising experimental model to tumorigenesis, angiogenesis, invasion and metastasis. The ionic liquid cetylpyridinium ampicillin [C16Pyr] [Amp] induces cytotoxicity in hormone-resistant breast and prostate cancer cell lines. To study the possible use of [C16Pyr] [Amp] as an anticancer, the toxicity towards zebrafish embryos should be evaluated first by an acute toxic assay that should be carried out following the OECD 236 Guideline.
- Marine cyanobacteria isolated from the portuguese coast as a source of bioactive compounds: cytotoxicity against human tumour cells and normal cellsPublication . Martins, Rosário; Costa-Rodrigues, João; Barros, Piedade; Costa, Margarida; Leão, PedroAs cianobactérias marinhas constituem uma fonte promissora de compostos com potencial antitumoral. Nos últimos anos, um arsenal de compostos tem sido revelado, alargando a gama de novos compostos ou estruturas de base ao desenvolvimento de novas drogas. Neste projeto tivemos como objetivo avaliar o potencial de cianobactérias da coleção LEGE-CC como fonte de compostos antitumorais. Foi também nosso objetivo avaliar os mecanismos que conduzem à inibição do crescimento celular nomeadamente o envolvimento da apoptose. O projeto resultou na seleção de estirpes promissoras com potencial bioativo. Os compostos hierridina B, hierridina C e bartolosidas foram isolados. A hierridina B foi citotóxica para a linha celular de adenocarcinoma do cólon HT-29, reduzindo a atividade mitocondrial e paragem do ciclo celular. A hierridina C não revelou citotoxicidade. No entanto, este composto foi testado quanto à sua atividade antiplasmodial, de onde resultou uma patente
- Projeto Nasythor - novos compostos naturais e sintéticos para o tratamento de tumores hormono-resistentesPublication . Quintela Vieira, Ana Filipa; Cruz, Agostinho; Oliveira, Ana; Pinho, Cláudia; Prudêncio, Cristina; Vieira, Mónica; Barros, Piedade; Ferraz, Ricardo; Martins, Rosário; Silva, ReginaUma equipa multidisciplinar do CISA-ESS | P. PORTO em colaboração com o CI|IPOP dedicou-se ao estudo do potencial anti-tumoral de novos compostos em tumores de grande incidência em Portugal: cancro da mama e da próstata. O potencial anti-tumoral de extratos de plantas e compostos sintéticos foi avaliado em linhas celulares de cancro da próstata e da mama, sendo a resposta terapêutica prevista através de amostras biológicas. Um líquido iónico provou estar associado à atenuação do fenótipo maligno das linhas celulares testadas, mostrando-se um promissor agente terapêutico anti-tumoral. A expressão de genes que se mostrou alterada após tratamento foi validada em amostras de pacientes com cancro da próstata e da mama. Os resultados foram divulgados sob a forma de artigo científico e de várias comunicações orais e posters em congressos nacionais e internacionais.