title: Respiration of mitochondria isolated from differentiated and undifferentiated HT29 colon cancer cells in the presence of various substrates and ADP generating systems.
abstract: 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.
authors.affiliation: Institut de Physiologie, INSERM U.317, Université Paul Sabatier, Toulouse, France.
authors.forename: T
authors.initials: T
authors.lastname: Gauthier
authors.forename: C
authors.initials: C
authors.lastname: Denis-Pouxviel
authors.forename: J C
authors.initials: JC
authors.lastname: Murat
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000263:Adenylate Kinase / Q000378:metabolism; D002454:Cell Differentiation; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology; D005947:Glucose / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D009701:Nucleoside-Diphosphate Kinase / Q000378:metabolism; D010101:Oxygen Consumption; D014407:Tumor Cells, Cultured / Q000378:metabolism* / Q000473:pathology
chemical_list: D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006593:Hexokinase; D000263:Adenylate Kinase; D009701:Nucleoside-Diphosphate Kinase; D005947:Glucose