Browsing by Author "Lima, Ana Paula Braga"

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    Additive effects of resveratrol and doxorubicin on bladder cancer cells.
    (2022) Soares, Luciana Bicalho Moreira; Lima, Ana Paula Braga; Melo, André Sacramento; Almeida, Tamires Cunha; Teixeira, Luiz Fernando de Medeiros; Silva, Glenda Nicioli da
    The treatment of bladder cancer remains a challenge in clinical practice. Different chemotherapeutic protocols can be used; however, it is common to observe tumor recurrence and secondary effects that result in toxicity. Doxorubicin (DOX), one of the most effective anticancer agents used to treat bladder cancer, can cause chronic cardiotoxicity, limiting its use in clinical practice. Resveratrol (RES), a natural product with potential antitumor activity against bladder cancer, is associated with rapid metabolism and low bioavailability and needs to be combined with chemotherapeutic drugs to improve its use. Our study aimed to assess the therapeutic effect of a low concentration of DOX (2µM) in combination with RES (150, 200 and 250µM) on two bladder cancer cell lines. We investigated the mechanism of interaction between the drugs by performing cytotoxicity, clonogenic, oxidative stress, cell migration, cell morphology and nuclear division index (NDI) assays. Cytotoxicity evaluation revealed an additive interaction between RES and DOX for both cell lines. Additionally, the results of cell colony formation, oxidative stress, cell migration, cell morphology and NDI assays showed that a combination of DOX and RES was more effective than RES or DOX alone. In conclusion, a low concentration of DOX combined with RES could potentiate the antitumor effects of the drugs on bladder cancer cells, thus overcoming the secondary effects caused by DOX and the low bioavailability of resveratrol.
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    Avaliação da genética do parasito e do hospedeiro, biologia do parasito e clínica da doença de Chagas em duas gerações de uma família.
    (2017) Lima, Ana Paula Braga; Silva, Glenda Nicioli da; Lana, Marta de; Silva, Glenda Nicioli da; Machado, Carlos Renato; Machado, Evandro Marques de Menezes
    A doença de Chagas, causada pelo protozoário Trypanosoma cruzi, é considerada uma doença multifatorial em que há interação de fatores do parasito e do hospedeiro. Estudos de correlação genética do parasito com suas propriedades biológicas, associando-as à genética do hospedeiro, vem sendo realizados com o objetivo de prever a evolução da infecção, auxiliando no diagnóstico, controle e conhecimento de sua epidemiologia. A proposta deste projeto foi avaliar a genética e a biologia do T. cruzi e a genética do hospedeiro de duas gerações de uma família com diagnóstico da doença de Chagas, procedentes da região do Alto Paranaíba, MG, constituída de mãe e suas cinco filhas. Amostras de sangue das voluntárias foram coletadas objetivando isolar o parasito e caracterizá-lo geneticamente. Entretanto, somente o parasito de uma única amostra foi isolado, sendo pertencente ao grupo genético ou DTU TcII. Na ausência de isolados do parasito da mãe e de quatro de suas filhas, a continuidade da caracterização genética do T. cruzi foi feita pela técnica de PCR-LSSP, com o objetivo de verificar a variabilidade intraespecífica do parasito. Com os resultados obtidos, um dendograma UPGMA foi construído, no qual as amostras foram divididas em três grupos distintos. O valor do índice Shannon (0,492) e a média do valor da heterozigosidade por locus (0,322) foram baixos, indicando baixa variabilidade genética entre os parasitos. A única amostra de parasito isolada apresentou baixa taxa de crescimento em meio de cultura acelular (LIT) e alta taxa de infectividade em células VERO e em camundongos. Três genes humanos relacionados à cardiopatia (TNF, WISP1 e TGF-β1) foram avaliados e as seis voluntárias apresentaram os mesmos genótipos para os três genes. Na ausência de diferenças genéticas, as voluntárias foram estudadas pelos questionários SF-36 (Versão Brasileira do Questionário de Qualidade de Vida) e Escala de Depressão Geriátrica de Yesavage para avaliar a autopercepção do estado de saúde e possibilidades de transtornos afetivos/depressivos. As voluntárias apresentaram transtornos afetivos associados a uma ruim/negativa auto-percepção do estado de saúde. Em conclusão, a compreensão da evolução clínica da DC vai além dos aspectos genéticos e biológicos do parasito e de aspectos genéticos do hospedeiro.
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    Efeitos antiproliferativos e toxicogenéticos da crisina em linhagens tumorais de bexiga com diferentes status do gene TP53.
    (2021) Lima, Ana Paula Braga; Silva, Glenda Nicioli da; Silva, Glenda Nicioli da; Dolabela, Maria Fâni; Ribeiro, Daniel Araki; Magalhães, Cíntia Lopes de Brito; Brandão, Geraldo Célio
    A atividade antitumoral da crisina, flavonoide encontrado no mel, na própolis e na Passiflora caerulea, tem sido estudada em diversos tipos de cânceres. No câncer de bexiga, seus efeitos citotóxicos já foram demonstrados, entretanto pouco se sabe sobre seu mecanismo de ação. Nesse contexto, esse trabalho teve como objetivo avaliar os efeitos antiproliferativos e toxicogenéticos e os possíveis mecanismos de ação molecular da crisina em células tumorais de bexiga com diferentes status do gene TP53 (RT4 – com gene TP53 selvagem; 5637 e T24 – com gene TP53 mutado). As células foram tratadas com diferentes concentrações de crisina (10, 20, 40, 60, 80 e 100 µM) para análise de citotoxicidade, proliferação celular, sobrevivência clonogênica, efeito pró-oxidante, efeitos genotóxicos e mutagênicos, alterações morfológicas, migração celular, cinética do ciclo celular, índice de divisão nuclear, perfil de metilação global e expressão dos genes SRC, PLK1, HOXB3, mTOR, FGFR3, c-MYC e RASSF1A. Os resultados mostraram que a crisina foi citotóxica e diminuiu a proliferação celular para as três linhagens estudadas, provavelmente através da produção de espécies reativas de oxigênio e da indução de danos no DNA das células. Além disso, a crisina diminuiu significativamente a formação de colônias e a migração celular nas três linhagens, sendo que nas linhagens com TP53 mutado, esses efeitos foram acompanhados pela diminuição da expressão de HOXB3 e SRC. A crisina diminuiu a densidade celular de todas as linhagens e alterou a morfologia das linhagens com TP53 mutado. Além disso, nas linhagens com TP53 mutado, a crisina causou parada do ciclo celular na fase G2/M, acompanhado pela diminuição da expressão de PLK1. Nas células RT4 e T24, a crisina aumentou as taxas de apoptose; nas células T24, taxas significativas de necrose também foram observadas. Nas células 5637, a crisina demonstrou interferir em eventos epigenéticos, aumentando o padrão de metilação global do DNA. Ademais, na linhagem T24, a modulação negativa dos genes c-MYC, FGFR3 e mTOR também parece contribuir para os efeitos antiproliferativos da crisina. Concluindo, a crisina diminui a proliferação e a migração celular independente do status de TP53 em células tumorais de bexiga, entretanto, os efeitos sobre a morfologia, cinética do celular e expressão de genes são dependentes do status de TP53.
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    Evaluation of parasite and host genetics in two generations of a family with Chagas disease.
    (2018) Lima, Ana Paula Braga; Oliveira, Maykon Tavares de; Silva, Rafael Rodrigues; Torres, Rosália Morais; Veloso, Vanja Maria; Lana, Marta de; Silva, Glenda Nicioli da
    Chagas disease, caused by the protozoan Trypanosoma cruzi, is considered to be a multifactorial disease associated with host and parasite genetics, which influence clinical aspects of the disease and other host conditions. In order to understand better the evolution of the disease, this study intended to evaluation of parasite and host genetics in two generations of a family with Chagas disease from the Alto Paranaiba region, Minas Gerais, Brazil, comprising a mother and her five daughters. Several features were evaluated, including the characterization of T. cruzi directly from the blood of patients, host polymorphisms of genes related to cardiomyopathy (TNF, WISP1, CCR5, and TGF-β1) and clinical aspects of the patients. To verify the intraspecific variability of the parasite, the characterization was done directly from human blood using the PCR-LSSP technique and analyzed based on Dice coefficient and unweighted pair group analysis (UPGMA). The host polymorphism was evaluated by PCR-RFLP. The global results showed low variability of the parasites characterized from blood of patients, through Shannon index (0.492) and mean heterozygosity value per locus (0.322). All six patients presented the same genetic polymorphism profile for TNF, WISP1, and TGF-β1, and only one patient was homozygous to CCR5, which suggests that there is no association between the clinical aspects of the patients and their genetic profiles. In conclusion, the findings confirm that the understanding of the clinical evolution of Chagas disease goes beyond the genetic aspects of the parasite and the host.
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    Inhibition of urinary bladder cancer cell proliferation by silibinin.
    (2020) Barros, Tatiane Martins Barcelos; Lima, Ana Paula Braga; Almeida, Tamires Cunha; Silva, Glenda Nicioli da
    Silibinin, a natural compound extracted from milk thistle, has demonstrated antitumor properties in urinary bladder cancer cells; however, the role of TP53 gene in these effects is unclear. In order to better understand the molecular and antiproliferative mechanisms of this compound, urinary bladder cancer cells with different TP53 gene status, RT4 (low-grade tumor, wild TP53 gene), 5637 (high-grade tumor, Grade 2, mutated TP53 gene), and T24 (high-grade tumor, Grade 3, mutated TP53 gene) were treated with several concentrations of silibinin (1, 5, 10, 50, 100, and 150 μM). Cytotoxicity, prooxidant effect, morphological changes, cell migration, cell cycle progression, global methylation profile, and relative expression of HOXB3, c-MYC, PLK1, SMAD4, SRC, HAT, HDAC, and RASSF1A genes were evaluated. The silibinin presented cytotoxic and prooxidant effects in the three cell lines. In mutated TP53 cells, significant interference in cell migration and cell cycle arrest at the G2/M phase was observed. Additionally, silibinin induced global DNA hypomethylation in the highest grade tumor cells. For wild-type TP53 cells, a sub-G1 apoptotic population was present. Furthermore, there was modulation of gene expression responsible for cell growth (SMAD and c-MYC), migration (SRC), cell cycle kinetics (PLK1), angiogenesis (HOXB3), and of genes associated with epigenetic events such as DNA acetylation (HAT) and deacetylation (HDAC). In conclusion, the silibinin inhibited the urinary bladder tumor cell proliferation independently of TP53 status; however, cell cycle effects, gene expression changes, and alteration of cell migration are dependent on TP53 status.
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    Naringin : antitumor potential in silico and in vitro on bladder cancer cells.
    (2022) Radicchi, Débora Carvalho; Melo, André Sacramento; Lima, Ana Paula Braga; Almeida, Tamires Cunha; Souza, Gustavo Henrique Bianco de; Silva, Glenda Nicioli da
    Introduction: Urothelial carcinoma is a significant public health problem. Transitional cell carcinoma (TCC) is the most common subtype, accounting for approximately 90 % of all bladder cancers. Chemotherapeutic protocols have been studied, but some present high toxicity and low tolerability. Naringin is a polyphenolic compound found mainly in citrus fruits, which antitumor activity has been studied in several types of cancer. However, there is little information about naringin effects on bladder cancer. This study aimed to evaluate the antitumor potential of nar- ingin in silico and in vitro using two bladder cancer cell lines Method: In silico analysis was carried out by PASS Online software. In vitro, the effects of naringin treatment (12.5 - 400 μM) were evaluated regarding its cytotoxicity, clonogenic survival, morphological alterations, cell cycle pro- gression, migration, and mutagenicity Results: In silico analyses predicted antitumor activity through several mechanisms of action. In vitro results showed naringin presented cytotoxic effects, reduced the number of colonies, inhibited cell migration, and changed the morphology and cell cycle progression of the two cell lines evaluated. However, naringin did not present mu- tagenic effects. Conclusions: Naringin has antiproliferative activity and is a promising candidate for bladder cancer treatment.
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    Toxicogenetic and antiproliferative effects of chrysin in urinary bladder cancer cells.
    (2020) Lima, Ana Paula Braga; Almeida, Tamires Cunha; Barros, Tatiane Martins Barcelos; Rocha, Lorrana Cachuite Mendes; Garcia, Camila Carrião Machado; Silva, Glenda Nicioli da
    The antitumour activity of chrysin have been studied in several types of cancer cells. In urinary bladder cancer, its cytotoxic effects have already demonstrated; however, its mechanism of action is not completely understood and the role of tumour protein p53 (TP53) gene in these effects is unclear. In this study, we investigated the role of chrysin (10, 20, 40, 60 80 and 100 µM) in progression of bladder tumour cells with different status of the TP53 gene and different degrees of tumour (RT4, grade 1, TP53 wild type; 5637, grade 2, TP53 mutated and T24, grade 3, TP53 mutated). Results demonstrated that chrysin inhibited cell proliferation by increasing reactive oxygen species and DNA damage and inhibited cell migration in all cell lines. In TP53 wild-type cells, a sub-G1 apoptotic population was present. In mutated TP53 cells, chrysin caused arrest at the G2/M phase and morphological changes accompanied by downregulation of PLK1, SRC and HOXB3 genes. In addition, in Grade 2 cells, chrysin induced global DNA hypermethylation and, in the highest-grade cells, downregulated c-MYC, FGFR3 and mTOR gene expression. In conclusion, chrysin has antiproliferative and toxicogenetic activity in bladder tumour cells independently of TP53 status; however, the mechanisms of action are dependent on TP53 status.