Valeria Righi1,
  2, Cibely Cristine Fontes De Oliveira3, Alexander A. Shestov4,
  Dionyssios Mintzopoulos1, 5, Nikolaos Psychogios1,
  5, Caterina Constantinou1, 6, Silvia Busquets3,
  Francisco J. Lopez-Soriano3, Sylvain Milot7, Francois
  Lepine8, Michael N. Mindrinos9, Laurence G. Rahme6,
  Josep M. Argiles3, Aria A. Tzika1, 5
 1NMR
  Surgical Laboratory, Department of Surgery, Massachusetts General Hospital
  and Shriners Burn Institute, Harvard Medical School, Boston, MA, United
  States; 2Department of Science for Life Quality, University of
  Bologna, Rimini, Italy; 3Cancer Research Group, Department de
  Bioqumica y Biologia Molecular, Facultat de Biologia, Universitat de
  Barcelona, Barcelona, Spain; 4Center for Magnetic Resonance
  Research, Department of Radiology, University of Minnesota Medical School,
  Minneapolis, MN, United States; 5Department of Radiology,
  Athinoula A. Martinos Center of Biomedical Imaging, Boston, MA, United
  States; 6Molecular Surgery Laboratory, Department of Surgery, Massachusetts
  General Hospital and Shriners Burn Institute, Harvard Medical School, Boston,
  MA, United States; 7INRS-Institut Armand-Frappier, Universit du
  Qubec, Laval,, Quebec, Canada; 8INRS-Institut Armand-Frappier,
  Universit du Qubec, Leval, Quebec, Canada; 9Department of
  Biochemistry, Stanford University School of Medicine, Stanford,, CA, United
  States
We tested the hypothesis that cancer promotes mitochondrial uncoupling in skeletal muscle. We employed in vivo 31P NMR on intact mice and GC-MS in skeletal muscle samples, in a mouse cancer cachexia model. ATP synthesis rate and TCA cycle flux were significantly reduced in cancer-bearing mice. The ratio of ATP synthesis rate/TCA cycle flux, which provides an index of mitochondrial coupling, was 32% less in cancer-bearing mice. Our results were cross-validated with genomic analysis, showing aberrant expression levels in key regulatory genes and by electron microscopy showing abnormal giant mitochondria.