Identificação de produtos do sobrenadante bacteriano com propriedade antitumoral em células de câncer de próstata
Data
2021-02-19
Tipo
Trabalho de conclusão de curso
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ISSN da Revista
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Resumo
O câncer de próstata é o tipo de tumor mais recorrente e o segundo com maior letalidade, em homens. Apesar da prostatectomia ser muito eficaz para o seu tratamento, em alguns casos o câncer pode voltar ainda mais agressivo, como uma metástase. O qual até o momento ainda não apresenta um tratamento efetivo. Entretanto, terapias bacterianas antitumorais tem sido cada vez mais estudadas e demonstrado sua capacidade de atuar contra tumores. Apresentando alternativas diferentes de tratamento, desde a utilização de bactérias como vetores ou então a extração das toxinas bacterianas com atividade antitumoral. Com isto alguns produtos do metabolismo bacteriano já foram demonstrados na literatura como sendo capazes de induzir a morte de células tumorais e têm sido testados em Ensaios clínicos como agentes antitumorais. Nosso laboratório possui uma coleção de isolados bacterianos provenientes de compostagem de matéria orgânica do Zoológico de São Paulo. Desta forma, em nosso trabalho testamos a atividade antitumoral de sobrenadante de culturas de 36 isolados de bactérias de compostagem sobre células de tumor de próstata PC3 e DU145 em cultura. Inicialmente procedemos a padronização do teste de atividade antitumoral com sobrenadante de culturas bacterianas crescidas em meio LB (Luria Bertani) ou em meio DMEM (Dulbeco Modified Eagle´s Medium). O ensaio utilizando meio DMEM mostrou-se mais adequado por não interferir na viabilidade das células tumorais em cultura. Realizada esta padronização, iniciou-se a análise da atividade antitumoral, e a partir de 36 isolados investigados, o sobrenadante de 3 isolados exibiram comprometimento da viabilidade das células tumorais por meio de ensaios com Prestoblue. Dentre os isolados cujos sobrenadantes reduzem a viabilidade das células tumorais em cultura, temos bactérias dos gêneros Serratia e Bacillus. Sendo estes identificados por MALDI-TOF e sequenciamento do gene do RNA Ribossomal 16S.
Prostate cancer is the most frequent type of tumor and the second most lethal in men. Although prostatectomy is a very effective treatment, in some cases cancer can return even more aggressively. To date, there are no effective treatment for the metastatic disease. Anti-tumor bacterial therapies have been increasingly studied and demonstrated their ability to act against tumors. There are different treatment alternatives, like the use of bacterial vectors or the extraction of bacterial toxins with antitumoral activity. Some products of bacterial metabolism have already been demonstrated in the literature as being capable of inducing the death of tumor cells and have been tested in clinical trials as antitumor agents. Our laboratory has a collection of bacterial isolates from composting organic matter from Zoológico de São Paulo. In this way, in our project we tested the antitumor activity of culture supernatant from about 36 isolates of composting bacteria on cultured prostate tumor cells. Initially, we standardized the protocols to evaluate the antitumor activity of supernatants from bacterial cultures grown in LB (Luria bertani) or DMEM (Dulbeco Modified Eagle´s Medium). The assay using DMEM was shown to be more appropriate as it did not interfere in viability of tumor cells in culture. Once this standardization was carried out, the analysis of the antitumor activity began, and from 36 investigated isolates, the supernatant of 3 isolates exhibited impairment of the viability of the tumor cells through tests with Prestoblue. Among the isolates whose supernatants reduce the viability of tumor cells in culture, we have bacteria of genus Serratia and Bacillus. Their identities were determined by MALDI-TOF and sequencing of the Ribosomal 16S RNA gene previously to this work.
Prostate cancer is the most frequent type of tumor and the second most lethal in men. Although prostatectomy is a very effective treatment, in some cases cancer can return even more aggressively. To date, there are no effective treatment for the metastatic disease. Anti-tumor bacterial therapies have been increasingly studied and demonstrated their ability to act against tumors. There are different treatment alternatives, like the use of bacterial vectors or the extraction of bacterial toxins with antitumoral activity. Some products of bacterial metabolism have already been demonstrated in the literature as being capable of inducing the death of tumor cells and have been tested in clinical trials as antitumor agents. Our laboratory has a collection of bacterial isolates from composting organic matter from Zoológico de São Paulo. In this way, in our project we tested the antitumor activity of culture supernatant from about 36 isolates of composting bacteria on cultured prostate tumor cells. Initially, we standardized the protocols to evaluate the antitumor activity of supernatants from bacterial cultures grown in LB (Luria bertani) or DMEM (Dulbeco Modified Eagle´s Medium). The assay using DMEM was shown to be more appropriate as it did not interfere in viability of tumor cells in culture. Once this standardization was carried out, the analysis of the antitumor activity began, and from 36 investigated isolates, the supernatant of 3 isolates exhibited impairment of the viability of the tumor cells through tests with Prestoblue. Among the isolates whose supernatants reduce the viability of tumor cells in culture, we have bacteria of genus Serratia and Bacillus. Their identities were determined by MALDI-TOF and sequencing of the Ribosomal 16S RNA gene previously to this work.