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Respiration of mitochondria isolated from differentiated and undifferentiated HT29 colon cancer cells in the presence of various substrates and ADP generating systems

1990; Elsevier BV; Volume: 22; Issue: 4 Linguagem: Inglês

10.1016/0020-711x(90)90145-s

1878-6014

Thierry Gauthier, Colette Denis, J.C. Murat,

Plant nutrient uptake and metabolism

1. Oxygen consumption was investigated in two cultured subpopulations of either undifferentiated (Glc+ cells) or differentiated (Glc- cells) HT29 colon cancer cells and in the corresponding isolated mitochondria. In Glc+ cells, a decrease of the respiration is induced by the presence of glucose (Crabtree effect), whereas it is not the case in Glc- cells. 2. The oxidative phosphorylation rate of Glc- mitochondria is found to be much higher than that of Glc+ mitochondria, due to a higher efficiency to oxidize glutamine, glutamate, 2-oxoglutarate, succinate or malate. 3. In both types of mitochondria, respiration can be supported by the ADP formed by adenylate kinase or nucleotide diphosphate kinase, and, although to a lesser extent in Glc- mitochondria, by hexokinase. 4. Glc+ cells are characterized by a low respiration capacity and a high glycolytic flux leading to the Crabtree effect. Glc- cells are characterized by a better correlation between a moderate glycolytic flux and a high respiratory capacity.