Cancer represents a set of more than 100 diseases, including malignant tumors from different locations. Strategies inducing differentiation have had limited success in the treatment of established cancers. Marine sponges are a biological reservoir of bioactive molecules, especially lectins. Several animal and plant lectins were purified with antitumor activity, mitogenic, anti-inflammatory and antiviral, but there are few reports in the literature describing the mechanism of action of lectins purified from marine sponges to induce apoptosis in human tumor cells. In this work, a lectin purified from the marine sponge Cinachyrella apion (CaL) was evaluated with respect to its hemolytic, cytotoxic and antiproliferative properties, besides the ability to induce cell death in tumor cells. The antiproliferative activity of CaL was tested against HeLa, PC3 and 3T3 cell lines, with highest growth inhibition for HeLa, reducing cell growth at a dose dependent manner (0.5–10 µg/mL). Hemolytic activity and toxicity against peripheral blood cells were tested using the concentration of IC₅₀ (10 µg/mL) for both trials and twice the IC₅₀ for analysis in flow cytometry, indicating that CaL is not toxic to these cells. To assess the mechanism of cell death caused by CaL in HeLa cells, we performed flow cytometry and western blotting. Results showed that lectin probably induces cell death by apoptosis activation by pro-apoptotic protein Bax, promoting mitochondrial membrane permeabilization, cell cycle arrest in S phase and acting as both dependent and/or independent of caspases pathway. These results indicate the potential of CaL in studies of medicine for treating cancer.

Objective: The aim of the present study was to evaluate the influence of a cryopreservation protocol on the proliferation and viability of stem cells from human exfoliated deciduous teeth (SHEDs). Materials and methods: Cells from the pulp of three deciduous teeth were isolated and characterized to confirm their stem cell nature. In second passage, part of the cells were submitted to normal conditions of cell culture (Control group), while part of the cells were maintained in 10% DMSO diluted in foetal bovine serum and submitted to the following cryopreservation protocol: 2 h at 4 °C, 18 h at −20 °C and then at −80 °C for two intervals (30 days – Cryopreservation I; and 180 days Cryopreservation II). Cell proliferation and cell cycle were evaluated at intervals of 24, 48 and 72 h after plating, and apoptosis-related events were analyzed at 72 h. Results: All groups exhibited an increase in the number of cells, and no significant differences between the cryopreserved and control groups were observed (p > .05). The distribution of cells in the cell cycle phases was consistent with cell proliferation, and the percentage of viable cells was higher than 99% in all groups, indicating that cell viability was not affected by the cryopreservation protocol throughout the experiment. Conclusion: The proposed cryopreservation protocol is adequate for the storage of SHED, permitting their use in future experimental studies.

Este artigo relata uma intervenção desenvolvida na Escola de Referência em Ensino Médio Professor Moacyr de Albuquerque, em Jaboatão dos Guararapes (Pernambuco – Brasil), com o objetivo de promover a educação ambiental e fortalecer o protagonismo juvenil no enfrentamento da crise climática. A metodologia, de abordagem quali-quantitativa, incluiu oficinas, construção de pluviômetro, aplicação de questionários, peça teatral e elaboração do Plano de Ação Escolar para Redução de Riscos e Adaptação Climática (PERAClima). As ações articularam princípios da educação ambiental, justiça climática e Educação para Redução de Riscos de Desastres (ERRD). Os resultados demonstram que a escola pode ser um espaço estratégico para o protagonismo da juventude, favorecendo a construção de soluções locais e o desenvolvimento da consciência ambiental, em contextos de maior vulnerabilidade socioambiental às mudanças climáticas.