O efeito da benfotiamina sobre enzimas alvo do ciclo de Krebs em cultura de células da linhagem 4T1

Abstract

Introduction: The energetic metabolism is one of the major differences between tumor and normal cells, of which tumor cells produce energy by anaerobic glycolysis preferably at the expense of mitochondrial oxidative phosphorylation Among the enzymes of the glycolytic metabolismo, the pyruvate dehydrogenase complex, which is located in the mitochondria, requires some cofactors to catalyze the conversion of pyruvate to acetyl-CoA. One of the cofactors is vitamin B1 which is also known as thiamine . Benfotiamine is a synthetic analogue of thiamine, having superior bioavailability. Objective: To investigate the influence of thiamine through its pro-forma, ie, benfotiamine on the energetic metabolism of tumor cells and programmed cell death in breast cancer cells of the 4T1 lineage. Materials and Methods: For this purpose, cells from the 4T1 lineage, which come from mouse breast cancer, were used. Three groups were formed according to the concentration of benfotiamine used in the culture medium, ie , Control, Benfo50 (benfotiamine 50µmol/L) and Benfo100 (benfotiamine 100µmol/L). Each group was performed in triplicate and kept for 24 or 72 hours exposed to benfotiamine (except the control). Results: The lactate concentration was lower in the groups exposed to benfotiamine (24h and 72h). Cytometry results showed a reduction in the number of living cells in the Bf50 and Bf100 groups compared to the control at both times. Greater number of cells in early apoptosis in the groups exposed to benfotiamine for 24 hours compared to the control, and in late apoptosis in both groups exposed to benfotiamine (24h and 72h) in all comparisons. The number of cells in necrosis was lower in the groups that stayed for a period of 24 hours than in the control, but the comparison between Bf50, Bf100 and the times showed a higher percentage of cells in necrosis in the period of 72 hours. The 24h Bf100 group was significantly higher than the 72h Bf100 in relation to thiamine. The comparison of group C 72h of TDP was less than the same group in 24 hours. The comparison of the TMP/TDP ratio was higher in the 72-hour C group than in the 24-hour C group.Conclusion: The exposure of a cancer cell line to benfotiamine potentiates the pathway of the pyruvate dehydrogenase enzymatic complex. Furthermore, it influences on cell death by apoptosis and decreases the number of cells undergoing necrosis within 24 hours. New studies are valid, given the scarcity of works in the area, to assess the mechanisms of this analogue in vitro inside the cell, enabling the beginning of the advance of specific therapies for an aggressive type of breast cancer.