Avaliação da atividade antitumoral de compostos n-fenilpiperazínicos em linhagem tumoral K562

• Autor(a) principal: Santos, Thaís Rosa Marques dos
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6756
• topic: LQFM166; Trifluormetil; Apoptose; K562; Morte Celular; LQFM166; Trifluoromethyl; Apoptosis; K562; Cell death; FARMACIA::FARMACOTECNIA

Although the efforts employed by scientific community to discover new anticancer therapies suitable to the increasing cancer incidence and multidrug resistance, its necessary to develop more selective and target driven drugs. Therefore, in this work we have done a screening with LQFM030 analogues, which is a Nutlin-1 analogue, aiming to evaluate their cytotoxic potential. Furthermore, we have evaluated the cytotoxicity, the morphological alterations and the cell death induction mechanisms of the compound LQFM166 in leukemia cell line K562. In parallel, we have investigated the security profile of the compound upon 3T3 basal cell line to estimate its LD50 and the Selectivity Index. The cytotoxicity assays included the tetrazolium salt (MTT) reduction and the Neutral Red Uptake assays, to assess the cytotoxicity of LQFM166 in K562 and 3T3 cell lines, respectively. The investigation of cell death induction mechanisms was carried out using flow cytometry, whereby we have evaluated the cells biochemistry parameters, including cell cycle progression, phosphatidylserine externalization, caspases 3/7, 8 and 9 activity, cytochrome c release from mitochondria, p21, p27, Bax, Bcl-2, cyclin-B1 and NFkB expression, using specific labeling for each assay. Data were analyzed by t test and the difference between control and treated groups averages was considered statistically significant when p<0,05. Regarding leukemia cell line K562, the compound LQFM166 was cytotoxic, showing a dose-time-dependent profile. Morphological alterations were observed after treatment with the compound at cellular and nuclear levels, which corroborate with apoptotic cell death. Additionally, treatment with the IC50 for 48 hours has promoted cellular and molecular changes that characterize this process, including phosphatidylserine externalization, increase of caspases 3/7, 8 and 9 activity, expression of pro-apoptotic proteins Bax, p21and p27, as well as diminution of Bcl-2 and cyclin-B1. We have also observed increase of cytochrome-c release and NFkB expression. Concerning the security profile, the compound was considered relatively selective, once the IC50 found to basal cell line (185,3 µM) was the double of the obtained to leukemia cell line regarding the same time of exposure (56,76 µM). The outcomes allow us to conclude that LQFM166 was cytotoxic upon leukemia cells K562, promoting morphological and biochemical alterations that indicate apoptotic cell death induction.