Desenvolvimento de nanopartículas lipídicas sólidas para carreamento de curcumina e análise de sua atividade contra células de câncer colorretal murino CT26

Tese (Doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Nanociência e Nanobiotecnologia, 2020.A quimioterapia contra o câncer continua sendo um desafio devido aos mecanismos de resistência das células tumorais e à toxicidade dos fármacos anticâncer. Estudos clínicos sugerem que as respostas imunitárias específicas para células cancerosas podem ser responsáveis, pelo menos em parte, para o sucesso clínico dos esquemas terapêuticos que dependem de indutores de morte celular imunogênica. Neste contexto, a eficiência de agentes anticâncer que são indutores de morte celular imunogênica dependem da capacidade do sistema imunitário do hospedeiro em reconhecer os sinais desta morte e gerar uma robusta resposta imunitária contra as células cancerosas. Morte celular imunogênica é uma via proeminente para a ativação do sistema imunitário contra o câncer, podendo resultar no sucesso de terapias anticâncer em longo prazo, devido às respostas imunitárias específicas, aumentando assim a eficácia da terapia em comparação com os agentes anticâncer convencionais utilizados.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Cancer chemotherapy remains a challenge due to the resistance mechanisms of tumor cells and the toxicity of anticancer drugs. Clinical studies suggest that specific immune responses to cancer cells may be responsible, at least in part, for the clinical success of therapeutic regimens that depend on inducers of immunogenic cell death. In this context, the efficiency of anti-cancer agents that are immunogenic cell death inducers depends on the ability of the host's immune system to recognize the signs of this death and generate a robust immune response against cancer cells. Immunogenic cell death is a prominent pathway for the activation of the immune system against cancer and may result in the success of anti-cancer therapies in the long term due to specific immune responses, thus, increasing the effectiveness of therapy compared to conventional anti- cancer agents

PVM/MA-shelled selol nanocapsules promote cell cycle arrest in A549 lung adenocarcinoma cells

Background: Selol is an oily mixture of selenitetriacylglycerides that was obtained as a semi-synthetic compound containing selenite. Selol is effective against cancerous cells and less toxic to normal cells compared with inorganic forms of selenite. However, Selol’s hydrophobicity hinders its administration in vivo. Therefore, the present study aimed to produce a formulation of Selol nanocapsules (SPN) and to test its effectiveness against pulmonary adenocarcinoma cells (A549). Results: Nanocapsules were produced through an interfacial nanoprecipitation method. The polymer shell was composed of poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA) copolymer. The obtained nanocapsules were monodisperse and stable. Both free Selol (S) and SPN reduced the viability of A549 cells, whereas S induced a greater reduction in non-tumor cell viability than SPN. The suppressor effect of SPN was primarily associated to the G2/M arrest of the cell cycle, as was corroborated by the down-regulations of the CCNB1 and CDC25C genes. Apoptosis and necrosis were induced by Selol in a discrete percentage of A549 cells. SPN also increased the production of reactive oxygen species, leading to oxidative cellular damage and to the overexpression of the GPX1, CYP1A1, BAX and BCL2 genes. Conclusions: This study presents a stable formulation of PVM/MA-shelled Selol nanocapsules and provides the first demonstration that Selol promotes G2/M arrest in cancerous cells

Epiisopilosine alkaloid has activity against schistosoma mansoni in mice without acute toxicity

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSchistosomiasis is a disease caused by parasites of the genus Schistosoma, currently affecting more than 200 million people. Among the various species of this parasite that infect humans, S. mansoni is the most common. Pharmacological treatment is limited135119CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP404134/2012-22014/02282-76, 2016/18023-5, 2016/22488-3The authors are grateful to Phytobios Pesquisa Desenvolvimento e Inovação LTDA.,company of the Centroflora Group, for its support during the realization of this research. SMA is grateful to Conselho Nacional de Desenvolvimento Científico e Tecnológico

An overview on immunogenic cell death in cancer biology and therapy

Immunogenic cell death (ICD) is a modality of regulated cell death that is sufficient to promote an adaptive immune response against antigens of the dying cell in an immunocompetent host. An important characteristic of ICD is the release and exposure of damage-associated molecular patterns, which are potent endogenous immune adjuvants. As the induction of ICD can be achieved with conventional cytotoxic agents, it represents a potential approach for the immunotherapy of cancer. Here, different aspects of ICD in cancer biology and treatment are reviewed

Epiisopilosine alkaloid has activity against Schistosoma mansoni in mice without acute toxicity

Schistosomiasis is a disease caused by parasites of the genus Schistosoma, currently affecting more than 200 million people. Among the various species of this parasite that infect humans, S. mansoni is the most common. Pharmacological treatment is limited to the use of a single drug, praziquantel (PZQ), despite reports of parasite resistance and low efficacy. It is therefore necessary to investigate new potential schistosomicidal compounds. In this study, we tested the efficacy of epiisopilosine (EPIIS) in a murine model of schistosomiasis. A single dose of EPIIS (100 or 400 mg/kg) administered orally to mice infected with adult S. mansoni resulted in reduced worm burden and egg production. The treatment with the lower dose of EPIIS (100 mg/kg) significantly reduced total worm burden by 60.61% (P < 0.001), as well as decreasing hepatosplenomegaly and egg excretion. Scanning electron microscopy revealed morphological changes in the worm tegument after treatment. Despite good activity of EPIIS in adult S. mansoni, oral treatment with single dose of EPIIS 100 mg/kg had only moderate effects in mice infected with juvenile S. mansoni. In addition, we performed cytotoxicity and toxicological studies with EPIIS and found no in vitro cytotoxicity (in HaCaT, and NIH-3T3 cells) at a concentration of 512 μg/mL. We also performed in silico analysis of toxicological properties and showed that EPIIS had low predicted toxicity. To confirm this, we investigated systemic acute toxicity in vivo by orally administering a 2000 mg/kg dose to Swiss mice. Treated mice showed no significant changes in hematological, biochemical, or histological parameters compared to non-treated animals. Epiisopilosine showed potential as a schistosomicidal drug: it did not cause acute toxicity and it displayed an acceptable safety profile in the animal model

Induction of Immunogenic Cell Death by Photodynamic Therapy Mediated by Aluminum-Phthalocyanine in Nanoemulsion

Photodynamic therapy (PDT) has been clinically employed to treat mainly superficial cancer, such as basal cell carcinoma. This approach can eliminate tumors by direct cytotoxicity, tumor ischemia, or by triggering an immune response against tumor cells. Among the immune-related mechanisms of PDT, the induction of immunogenic cell death (ICD) in target cells is to be cited. ICD is an apoptosis modality distinguished by the emission of damage-associated molecular patterns (DAMP). Therefore, this study aimed to analyze the immunogenicity of CT26 and 4T1 treated with PDT mediated by aluminum-phthalocyanine in nanoemulsion (PDT-AlPc-NE). Different PDT-AlPc-NE protocols with varying doses of energy and AlPc concentrations were tested. The death mechanism and the emission of DAMPs–CRT, HSP70, HSP90, HMGB1, and IL-1β–were analyzed in cells treated in vitro with PDT. Then, the immunogenicity of these cells was assessed in an in vivo vaccination-challenge model with BALB/c mice. CT26 and 4T1 cells treated in vitro with PDT mediated by AlPc IC50 and a light dose of 25 J/cm2 exhibited the hallmarks of ICD, i.e., these cells died by apoptosis and exposed DAMPs. Mice injected with these IC50 PDT-treated cells showed, in comparison to the control, increased resistance to the development of tumors in a subsequent challenge with viable cells. Mice injected with 4T1 and CT26 cells treated with higher or lower concentrations of photosensitizer and light doses exhibited a significantly lower resistance to tumor development than those injected with IC50 PDT-treated cells. The results presented in this study suggest that both the photosensitizer concentration and light dose affect the immunogenicity of the PDT-treated cells. This event can affect the therapy outcomes in vivo

Effect on egg development and on Stoll egg count of a single dose 100 mg/kg of EPIIS administered to mice harboring a 60-day-old adult <i>S</i>. <i>mansoni</i> infection.

<p><b>(A)</b> EPIIS effect on egg development stages (oogram) <b>(B)</b> Effect on Stoll egg count. Points represent data from individual mice that were infected and treated with EPIIS, or infected and untreated (control). The horizontal bars represent median values. **<i>P</i> < 0.01 and ***<i>P</i> < 0.001 compared with untreated groups.</p

<i>In silico</i> analysis of toxicological properties of EPIIS predicted using the pkCSM methodology.

<p><i>In silico</i> analysis of toxicological properties of EPIIS predicted using the pkCSM methodology.</p

Physicochemical parameters through <i>in silico</i> analysis of EPIIS using pkCSM methodology.

<p>Physicochemical parameters through <i>in silico</i> analysis of EPIIS using pkCSM methodology.</p