title: Loss of strength capacity is associated with mortality, but resistance exercise training promotes only modest effects during cachexia progression.
abstract: OBJECTIVE
  Resistance exercise training (RET) has been adopted as non-pharmacological anti-catabolic strategy. However, the role of RET to counteract cancer cachexia is still speculative. This study aimed to verify whether short-term RET would counteract skeletal muscle wasting in a severe cancer cachexia rat model.
  
  
  METHODS
  Wistar rats were randomly allocated into four experimental groups; 1) untrained control rats (control), 2) rats submitted to RET (control+RET), 3) untrained rats injected with Walker 256 tumor cells in the bone marrow (tumor) and 4) rats injected with Walker 256 tumor cells in the bone marrow and submitted to RET (tumor+RET).
  
  
  RESULTS
  Tumor group displayed skeletal muscle atrophy fifteen days post tumor cells injection as assessed by plantaris (-20.5%) and EDL (-20.0%) muscle mass. EDL atrophy was confirmed showing 43.8% decline in the fiber cross sectional area. Even though RET increased the lactate dehydrogenase protein content and fully restored phosphorylated form of 4EBP-1 to the control levels in skeletal muscle, it failed to rescue muscle morphology in tumor-bearing rats. Indeed, RET did not mitigated loss of muscle function, anorexia, tumor growth or mortality rate. However, loss of strength capacity (assessed by 1-RM test performance) demonstrated a negative correlation with rats' survival (p=0.02; r=0.40), suggesting that loss of strength capacity might predict cancer mortality.
  
  
  CONCLUSIONS
  These results demonstrated that bone marrow injection of Walker 256 tumor cells in rats induces cancer cachexia, strength capacity is associated with cancer survival and short-term RET promotes only modest effects during cachexia progression.
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Willian
authors: W
authors: das Neves
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Christiano Robles Rodrigues
authors: CR
authors: Alves
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Ney Robson
authors: NR
authors: de Almeida
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Fátima Lúcia Rodrigues
authors: FL
authors: Guimarães
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Paulo Rizzo
authors: PR
authors: Ramires
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Patricia Chakur
authors: PC
authors: Brum
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil. Electronic address: lanchajr@usp.br.
authors: Antonio Herbert
authors: AH
authors: Lancha
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D000855:Anorexia / Q000628:therapy; D002100:Cachexia / Q000150:complications* / Q000628:therapy*; D045744:Cell Line, Tumor; D018450:Disease Progression; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009133:Muscular Atrophy / Q000150:complications* / Q000628:therapy*; D009369:Neoplasms / Q000150:complications / Q000628:therapy; D051381:Rats; D017208:Rats, Wistar; D055070:Resistance Training; D015996:Survival Rate
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C511885:PA2G4 protein, rat; D007770:L-Lactate Dehydrogenase
keywords: Atrophy; Physical activity; Skeletal muscle wasting