Efeitos biológicos e atividade terapêutica de nanocápsulas de selol em carcinoma de pulmão de células não pequenas

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2014.O selol é uma mistura oleosa de selenitotriacilgliceróis efetivo contra as células de câncer e menos tóxico às células normais em comparação às formas inorgânicas de selenito. No entanto, sua hidrofobicidade é um obstáculo à sua administração in vivo. Neste contexto, desenvolveu-se para o presente estudo uma formulação de nanocápsulas contendo selol estabilizadas pelo copolímero poli (vinil, metil-éter-co-anidrido maléico) (PVM/MA) (SNP). O objetivo deste trabalho foi caracterizar a formulação de nanocápsulas de selol e avaliar sua efetividade contra células de carcinoma de pulmão do tipo não-pequenas (CPCNP) em modelos in vitro e in vivo. As nanocápsulas de selol mostraram-se monodispersas e estáveis. As linhagens celulares de CPCNP utilizadas nos ensaios in vitro foram carcinoma de células escamosas (NCIH 2170) e adenocarcinoma (A549). Ambos selol livre (S) e SNP reduziram significantemente a viabilidade das células de adenocarcinoma pulmonar (A549), enquanto S reduziu mais pronunciadamente a viabilidade das células não tumorais em comparação a SNP. Células da linhagem NCIH 2170 não foram responsivas ao selol livre e encapsulado nas condições estudadas. O efeito supressor de SNP sobre as células A549 foi principalmente associado ao bloqueio na progressão do ciclo celular na fase G2/M, corroborado pelas reduções nas expressões gênicas de CCNB1 e CDC25C. Apoptose e necrose foram induzidas por S e SNP em porcentagens discretas de células A549. No entanto, SNP parece ter causado alterações celulares capazes de aumentar a produção de espécies reativas de oxigênio e os níveis dos transcritos de GPX1, CYP1A1, BAX e BCL2. Em camundongos portadores de adenocarcinoma de pulmão, SNP reduziu a área dos nódulos tumorais superficiais, no entanto não provocou redução do volume dos nódulos tumorais totais. A pequena diminuição da porcentagem de proliferação das células tumorais tratadas não foi estatisticamente significante. Os resultados bioquímicos e hematológicos são sugestivos de baixa toxicidade sistêmica por SNP. As propriedades de superfície das nanocápsulas de selol apontam para características compatíveis com o tratamento de tumores in vivo: baixos potenciais inflamatório e hemolítico, ausente ativação do sistema complemento e leves ou ausentes alterações conformacionais de proteínas plasmáticas. Concluindo, o presente estudo apresenta uma formulação de nanocápsulas de selol com potencial para ser utilizada como terapia contra células de adenocarcinoma de pulmão, e demonstra, pela primeira vez, bloqueio no ciclo celular induzido pelo selol. __________________________________________________________________________________________________ ABSTRACTSelol is an oily mixture of selenitetriacylglycerides that is effective against cancerous cells and less toxic to normal cells in comparison to the inorganic forms of selenite. However, its hydrophobicity hinders its administration in vivo. In this context, it was developed for the present study a formulation of poly (methyl vinyl ether-co-maleic anhydride) (PVM/MA)-stabilized selol nanocapsules (SNP). The aim of this work was to characterize the formulation of selol nanocapsules and evaluate its effectiveness against non-small cells lung carcinoma (NSCLC) at in vitro and in vivo models. Selol nanocapsules were monodisperse and stable. NSCLC cell lines used in in vitro assays were squamous cells carcinoma (NCIH 2170) and adenocarcinoma (A549). Both free selol (S) and SNP significantly reduced the viability of pulmonary adenocarcinoma (A549) cells, whereas S reduced more pronouncedly the viability of non-tumor cells, in comparison to SNP. The NCIH 2170 line cells were not responsive to both free selol and encapsuled under the conditions studied. The SNP suppressor effect at A549 cells was mainly associated to an arrest of cell cycle progression at G2/M phase, corroborated by down-regulation of CCNB1 and CDC25C genes. Apoptosis and necrosis were induced by S and SNP in discrete percentages of A549 cells. However, SNP appears to have induced cell changes able to increase reactive oxygen species production and transcripts levels of GPX1, CYP1A1, BAX and BCL2. In mice with lung adenocarcinoma, SNP reduced the area of superficial tumor nodules, however caused no reduction in the volume of total tumor nodules. Subtle decrease of proliferation percentage of treated tumor cells was not statistically significant. Biochemical and hematological findings are suggestive of low systemic toxicity by SNP. The surface properties of the selol nanocapsules indicate characteristics compatible with tumors treatment in vivo: low inflammatory and hemolytic potentials, no activation of complement system and mild or absent conformational changes of plasma protein. Concluding, this present study exhibits a selol nanocapsule with potential to be used as a therapy against lung adenocarcinoma cells, and shows, for the first time, cell cycle arrest induced by selol

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

Lip squamous cell carcinoma in a Brazilian population : epidemiological study and clinicopathological associations

Objectives: It was evaluated epidemiological aspects of primary lip squamous cell carcinoma (LSCC) and its associations with clinicopathological factors. Study design: This retrospective, cross-sectional study analysed a sociodemographic, clinical, and morphological data of HNSCC in a Brazilian population (n=30). Data analysis included descriptive statistics and bivariate analyses using the chi-square and Fisher's exact tests to compare the variables. Results: The LSCC represented 10.8% of all oral cavity squamous cell carcinoma. Lip malignant disease was more prevalent in elderly men, with male-to-female ratio of 5:1. Lower lip was more affected. It was observed high rates of chronic solar exposure, and tobacco and alcohol drinking habits. Clinically, early TNM staging, small tumour lesions, and non-metastatic disease were predominant findings. It was identified a high frequency of well differentiated tumor samples. Worse Karnofsky performance status was associated with cervical metastasis. Conclusions: Our findings showed that LSCC patients exhibited similar epidemiological and clinical profiles as noted in other studies. Still, the occurrence of metastatic disease was associated with a worse physical performance status of the LSCC patients during diagnosis. © Medicina Oral S. L

challenges and strategies for adherence to treatment during the COVID-19 pandemic in Brazil

Funding Information: The study was supported by the São Paulo Research Foundation (FAPESP) [Grant 2018/14337–0], the National Council for Scientific and Technological Development (CNPq) [Grant 130160/2020–2] and Research Productivity Grant from the National Council for Scientific and Technological Development (CNPq) [Grant 304483/2018–4 - PQ modality (Level 1C)]. Publisher Copyright: © 2021, The Author(s).Background: Multidrug-resistant tuberculosis (MDR-TB) is a serious phenomenon on a global scale that can worsen with the COVID-19 pandemic. The study aimed to understand the perceptions of health professionals about MDR-TB, their strategies to ensure adherence to treatment and their challenges in the context of the COVID-19 pandemic in a priority municipality for disease control. Methods: We conducted a qualitative study and recruited 14 health providers (four doctors, three nurses, three nursing technicians, three nursing assistants and a social worker) working in a city in the state of São Paulo, Brazil. Remote semi-structured interviews were conducted with the participants. For data analysis, the thematic content analysis technique was applied according to the study’s theoretical framework. Results: The study revealed the causes of MDR-TB are associated with poverty, vulnerability, and social risk. A pre-judgement from the providers was observed, namely, all patients do not adhere due their resistance and association with drug abuse or alcoholism. The study also observed difficulty among health providers in helping patients reconstruct and reframe their life projects under a care perspective, which would strengthen adherence. Other issues that weakened adherence were the cuts in social protection and the benefits really necessary to the patients and a challenge for the providers manage that. The participants revealed that their actions were impacted by the pandemic and insecurity and fear manifested by patients after acquiring COVID-19. For alleviating this, medical appointments by telephone, delivery of medicine in the homes of patients and visits by health professionals once per week were provided. Conclusion: The study advances knowledge by highlighting the challenges faced by the health system with the adherence of patients with MDR-TB in a context aggravated by the pandemic. An improvement in DOT is really necessary to help the patients reframe their lives without prejudices, face their fears and insecurity, recover their self-esteem and motivate in concluding their treatment.publishersversionpublishe

Methodological validation of a vertical ladder with low intensity shock stimulus for resistance training in C57BL/6 mice: Effects on muscle mass and strength, body composition, and lactate plasma levels

The objective of this study was to evaluate the effects of a vertical ladder device for resistance exercises with or without electrical shock stimulus on muscle strength, body composition, limb volume, muscle fibres and plasma lactate and glycemia of female mice. This device is represented by a vertical ladder with electrostimulation. It was analysed in groups of C57BL/6 mice practicing spontaneous physical activity in enriched environment, practicing resisted climbing exercises, practicing resistance exercises with the utility model in question and controls. The acute effects of blood lactate and dark light-box behaviour, and the short-term chronic effects of muscle strength, limb volume, body composition, muscle fibre area, and central and light-dark quantification were verified. According to the findings, the vertical electrostimulation ladder model presented acute effects on lactate levels, similar to other experimental models of resistance exercise and physical activity. The behaviour in the light-dark box test showed no difference between the groups. Regarding the short-term chronic response, the best results were obtained in the impact-stimulated resistive exercise in the limb traction muscle variables, greater brown adipose tissue weight, greater quadriceps femoral muscle structure, limb and greater weight number of nuclei in the skeletal striated muscle fibres. The use of the prototype showed similarities in the acute and chronic adaptations expected in resistance training. However, new study proposals should be encouraged, as the data presented here are the first notes on the use of this utility model.We would like to thank the Foundation for Research Support of the Minas Gerais State (FAPEMIG; grant numbers: PPM-00029-17 and DEG-00010-16); National Council for Scientific and Technological Development (CNPq, grant number: 150038/2017-8 and 430759/2016-9); and the Coordination of Improvement of Higher Education Personnel (CAPES) for the support to carry out this study. AMB De-Paula is research productivity fellow of the CNPq

DNA repair gene excision repair cross complementing-group 1 (ERCC1) in head and neck squamous cell carcinoma: analysis of methylation and polymorphism (G19007A), protein expression and association with epidemiological and clinicopathological factors

Aims: To evaluate the associations of excision repair cross complementing-group 1 (ERCC1) (DNA repair protein) (G19007A) polymorphism, methylation and immunohistochemical expression with epidemiological and clinicopathological factors and with overall survival in head and neck squamous cell carcinoma (HNSCC) patients. Methods and results: The study group comprised 84 patients with HNSCC who underwent surgery and adjuvant radiotherapy without chemotherapy. Bivariate and multivariate analyses were used. The allele A genotype variant was observed in 79.8% of the samples, GG in 20.2%, GA in 28.6% and AA in 51.2%. Individuals aged more than 45 years had a higher prevalence of the allelic A variant and a high (83.3%) immunohistochemical expression of ERCC1 protein [odds ratio (OR) = 4.86, 95% confidence interval (CI): 1.2-19.7, P = 0.027], which was also high in patients with advanced stage (OR= 5.04, 95% CI: 1.07-23.7, P = 0.041). Methylated status was found in 51.2% of the samples, and was higher in patients who did not present distant metastasis (OR = 6.67, 95% CI: 1.40-33.33, P = 0.019) and in patients with advanced stage (OR = 5.04, 95% CI: 1.07-23.7, P = 0.041). At 2 and 5 years, overall survival was 55% and 36%, respectively (median = 30 months). Conclusion: Our findings may reflect a high rate of DNA repair due to frequent tissue injury during the lifetime of these individuals, and also more advanced disease presentation in this population with worse prognosis

Zika, dengue and chikungunya population prevalence in Rio de Janeiro city, Brazil, and the importance of seroprevalence studies to estimate the real number of infected individuals.

In the last 40 years, Latin America countries, including Brazil, have suffered from the emergence and reemergence of arboviruses, first Dengue (DENV) and recently Zika (ZIKV) and Chikungunya (CHIKV). All three arboviruses are currently endemic in Brazil and have caused major outbreaks in recent years. Rio de Janeiro city, host of the last Summer Olympic Games and the Football World Cup, has been specially affected by them. A surveillance system based on symptomatic reports is in place in Rio, but the true number of affected individuals is unknown due to the great number of Zika, Dengue and Chikungunya asymptomatic cases. Seroprevalence studies are more suitable to evaluate the real number of cases in a given population. We performed a populational seroprevalence survey in Rio, with recruitment of a sample of volunteers of all ages and gender from July to October 2018, within randomly selected census tracts and household. A total of 2,120 volunteers were interviewed and tested with rapid immunochromatographic test for ZIKV, DENV and CHIKV. Individuals with positive results for IgG and/or IgM from only one virus were classified accordingly, while those with test results positive for both ZIKV and DENV were classified as flaviviruses. We corrected for sample design and non-response in data analysis, and calculated point estimate prevalence and 95% confidence intervals for each virus. Arbovirus prevalence in the Rio's population (n = 6,688,927) was estimated at 48.6% [95% CI 44.8-52.4] (n = 3,254,121) for flaviviruses and at 18.0% [95% CI 14.8-21.2] (n = 1,204,765) for CHIKV. Approximately 17.0% [95% CI 14.1-20.1] (n = 1,145,674) of Rio´s population had no contact with any of the three arboviruses. The reported cases of Zika, Dengue and Chikungunya by the current surveillance system in place is insufficient to estimate their real numbers, and our data indicate that Zika seroprevalence could be at least five times and Chikungunya 45 times bigger. The high number of individuals having never been infected by any of the three arboviruses, may indicate a proper scenario for future outbreaks

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data