AVALIAÇÃO DOS EFEITOS TÓXICOS E CAPACIDADE DE INDUÇÃO DE MORTE E PARADA DE CICLO EM CÉLULAS TUMORAIS B16F10 POR COMPOSTOS CONTENDO O GRUPO MALEIMIDA E 1,4-DIOXO-2-BUTENIL LIGADOS AO ENXOFRE

Abstract

Cancer reached more than 17 million new cases in the world in 2018, leading to the death of almost 9.5 million people. When it comes to melanoma, a more aggressive type of skin cancer, there has been an increase in the number of cases in the 21st century. Although surgical treatment remains the "gold standard", recent advances in immunotherapy and targeted molecular therapy for metastatic diseases have showed very promising results. It emphasizes the importance of studying new molecular structures and building new substances that can be used in the therapy of this disease. In this study, evaluation and screening of five compounds that combine the maleimide and 1,4-dioxo-2-butenyl group, containing sulfur in its structure, in B16F10 tumor cells in relation to cytotoxicity, through the MTT assay, emerged with more significant results in cell proliferation inhibition, called Compound 3 and Compound 5. The cells were subjected to 24 hours of treatment and evaluated in a flow cytometer for membrane integrity and cell count, demonstrating a significant reduction in the number of cells in treatment with both compounds, at all concentrations tested, without significant change in membrane integrity. Then, a cell cycle profile was evaluated, showing marked retention in the G1 phase, mainly in Compound 3, in addition to the appearance of a sub-G1 population, providing evidence of cell death, confirmed by the induction of initial apoptosis in both compounds and concentrations tested. An increase in ROS is observed from the concentration of 125 μM in both compounds, after 3 hours of treatment. The genotoxicity study identifies expressive results in both molecules. Compound 5 proved to be more efficient in genotoxic damage than Compound 3, increasing both the length of the comet and the amount of DNA in the tail. The study is concluded with gene expression, obtaining a considerable increase in GADD45a, a marker of generalized damage, increase in ATR, TP53, CDKN1a, CHK2, COX2 and CASP3, in both compounds, at concentrations of 125 μM and 500 μM. Activation of GADD45a indicates that damage caused by both compounds is signaled by activation of the p38/JNK pathway, in this case, possibly independent of P53 activation. These results, added together, indicate a future therapeutic possibility for them to fight melanoma.