Efeitos citot?xicos e toxicogen?micos da silibinina em c?lulas de c?ncer de bexiga com diferentes status do gene TP53.

Programa de P?s-Gradua??o em Ci?ncias Farmac?uticas. CIPHARMA, Escola de Farm?cia, Universidade Federal de Ouro Preto.A silibinina, um composto natural extra?do de frutos e sementes de Silybum marianum, demonstrou propriedades antitumorais em c?lulas de c?ncer de bexiga; no entanto, o papel do gene TP53 nestes efeitos n?o ? claro. Para entender melhor os mecanismos moleculares e antiproliferativos deste composto, c?lulas de c?ncer de bexiga com diferentes status do gene TP53, RT4 (tumor de baixo grau, gene TP53 selvagem), 5637 (grau 2, tumor de alto grau, gene TP53 mutado) e T24 (grau 3, tumor de alto grau, gene TP53 mutado), foram tratadas com silibinina nas concentra??es 1; 5; 10; 50; 100 e 150 ?M. V?rios par?metros foram avaliados, incluindo citotoxicidade, efeito pr?-oxidante, altera??es morfol?gicas, migra??o celular, progress?o do ciclo celular, perfil de metila??o global e express?o relativa dos genes HOXB3, c-MYC, PLK1, SMAD4, SRC, HAT, HDAC e RASSF1A. Os resultados mostraram que a silibinina apresentou efeitos citot?xicos e pr?oxidantes nas tr?s linhagens celulares. A interfer?ncia significativa na migra??o celular e a parada do ciclo celular na fase G2 / M foram observadas em c?lulas com o gene TP53 mutado. Al?m disso, a silibinina induziu hipometila??o global de DNA nas c?lulas com maior grau de tumor. Para as c?lulas TP53 do tipo selvagem, o conte?do sub-G1 estava presente de forma significativa. Al?m disso, houve modula??o da express?o g?nica dos oncogenes respons?veis pelo crescimento celular (SMAD e c-MYC), migra??o (SRC e HOXB3), cin?tica do ciclo celular (PLK1), angiog?nese (HOXB3) e genes associados a eventos epigen?ticos como acetila??o de DNA (HAT) e desacetila??o (HDAC). Em conclus?o, a silibinina inibe a prolifera??o celular independentemente do status de TP53. Entretanto, os efeitos sobre o ciclo celular, a migra??o celular e a express?o g?nica s?o dependentes do status de TP53.Silibinin, a natural compound extracted from milk thistle, has demonstrated antitumor properties in 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, 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 ?M). Cytotoxicity, pro-oxidant 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 results shown silibinin presented cytotoxic and pro-oxidant effects in the three cell lines. In mutated TP53 cells, significant interference in the cell migration and cell cycle arrest at G2/M phase were observed. In addition, silibinin induced global DNA hypomethylation and downregulated RASSF1A gene expression in highest tumor grade cells. For wild-type TP53 cells, a sub-G1 apoptotic population was present. Furthermore, there was modulation gene expression responsible for cell growth (SMAD and C-MYC), migration (SRC and HOXB3), cell cycle kinetics (PLK1), and genes associated to epigenetic events such as DNA acetylation (HAT) and deacetylation (HDAC). In conclusion, silibinin inhibited the bladder tumor cell proliferation in TP53 status independent way, however cell cycle effects, gene expression changes and alteration of cell migration are dependent TP53 status