title: Changes in myostatin signaling in non-weight-losing cancer patients.
abstract: BACKGROUND
  Myostatin is a negative regulator of skeletal muscle mass. We recently demonstrated that myostatin expression is upregulated in an experimental model of cancer cachexia, suggesting that modulations of this pathway might play a pathogenic role in cancer-related muscle wasting. The present study was designed to investigate whether myostatin signaling is modulated in the muscle of non-weight-losing (nWL) patients with lung and gastric cancer.
  
  
  METHODS
  Myostatin signaling was studied in muscle biopsies obtained during surgical procedure from nWL patients affected by gastric (n=16) or lung (n=17) cancer. Western blotting was applied to test both the total expression of myostatin and the expression of phosphorylated form of GSK-3beta and Smad2/3.
  
  
  RESULTS
  In patients with gastric cancer, the expression of both myostatin and phosphorylated GSK-3beta (p-GSK3β) were significantly increased. By contrast, in patients with lung cancer, myostatin levels were comparable to controls, whereas the expression of p-GSK3β significantly decreased in patients with disease stage III/IV.
  
  
  CONCLUSIONS
  Myostatin signaling is altered in nWL cancer patients. Different tumor types may give rise to different patterns of molecular changes within the muscle, which occur even before cachexia becomes clinically apparent.
authors.affiliation: Department of Clinical Medicine, Sapienza, University of Rome, Rome, Italy.
authors.forename: Zaira
authors.initials: Z
authors.lastname: Aversa
authors.forename: Andrea
authors.initials: A
authors.lastname: Bonetto
authors.forename: Fabio
authors.initials: F
authors.lastname: Penna
authors.forename: Paola
authors.initials: P
authors.lastname: Costelli
authors.forename: Gaetano
authors.initials: G
authors.lastname: Di Rienzo
authors.forename: Angelo
authors.initials: A
authors.lastname: Lacitignola
authors.forename: Francesco M
authors.initials: FM
authors.lastname: Baccino
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ziparo
authors.forename: Paolo
authors.initials: P
authors.lastname: Mercantini
authors.forename: Filippo
authors.initials: F
authors.lastname: Rossi Fanelli
authors.forename: Maurizio
authors.initials: M
authors.lastname: Muscaritoli
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D002100:Cachexia / Q000209:etiology / Q000378:metabolism; D005260:Female; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D055435:Myostatin / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000150:complications*; D015854:Up-Regulation; D015431:Weight Loss
chemical_list: D015415:Biomarkers; D055435:Myostatin; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3