In vitro variations of the metabolic activity in macrophages against lung cancer andhepatocarcinoma tumor cells

Abstract

Introduction. Metabolic activity determines the phenotype of macrophages, which can be oriented towards activation of defense mechanisms or tissue repair (phenotypic plasticity). Objectives. To evaluate the behavior of the main enzymes involved in the metabolic pathways of energy production in macrophages exposed to two tumor environments. Methods. In vitro experimental study that consisted of measuring the enzymatic activity of hexokinase (HQN), lactate dehydrogenase (LDH), isocitrate dehydrogenase (IDH) and glucose-6-phosphate dehydrogenase (G6P) by spectrophotometric absorbance in macrophages exposed to lung cancer and hepatocarcinoma cells. We compared the medians of enzyme activity between the isolated cell lines and their co-cultures (Kruskal-Wallis (H) test) and the medians of enzyme activity between each co-culture (Mann-Whitney U test). Results. The enzymatic activity of LDH was significantly higher in macrophages exposed to the hepatocellular carcinoma line, at 0 (H = 5,96, p = 0,03), 2 (H = 6,49, p = 0,01) and 6 hours (H = 7,20, p = 0,004). On the contrary, the enzymatic activity of IDH and HQN in cocultures was significantly lower compared to monocultures. The G6P had lower activity after 2 hours in macrophage monocultures compared to cocultures in the hepatocellular carcinoma line. The enzymatic activity of LDH, IDH, G6P and HQN in macrophages exposed to lung cancer cells was lower compared to macrophages and tumor cells in monoculture. Conclusion: The interaction between macrophages and tumor cells produces changes in the ways glucose is used.