title: Bosutinib, an SRC inhibitor, induces caspase-independent cell death associated with permeabilization of lysosomal membranes in melanoma cells.
abstract: BACKGROUND
  SRC kinase (SRC proto-oncogene, non-receptor tyrosine kinase) is a promising target for the treatment of solid cancers including human melanoma. Bosutinib (Bosu), a SRC inhibitor, has already been applied to the treatment of human chronic myelogenous leukemia and also has been assessed its safety in dogs.
  
  
  OBJECTIVE
  The aim of this study was to clarify a novel anti-tumour mechanism of Bosu in canine and human melanoma cells.
  
  
  METHODS
  The canine and human melanoma cells were treated with Bosu and its effects were evaluated by the cell viability, the protein expression levels such as caspase-3 and LC3, Annexin V/Propidium iodide staining, and confocal immunostaining.
  
  
  RESULTS
  Bosu induced the massive caspase-independent cell death, and blocked autophagy flux, which resulted from lysosomal dysfunction. Lysosomal dysfunction caused by Bosu was due to lysosomal membrane permeabilization (LMP), which resulted in the release of lysosomal hydrolases including cathepsin B.
  
  
  CONCLUSIONS
  Our data suggest that Bosu induces the cell death through induction of LMP in melanoma cells and is a promising therapeutic agent for treatment of melanoma in both dogs and humans.
authors.affiliation: Laboratory of Veterinary Radiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.|Biomedical Science Center for Translational Research, The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan.
authors.forename: S
authors.identifier: http://orcid.org/0000-0002-0915-4829
authors.initials: S
authors.lastname: Noguchi
authors.affiliation: Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shibutani
authors.affiliation: Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fukushima
authors.affiliation: Laboratory of Veterinary Clinical Oncology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.affiliation: The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Igase
authors.affiliation: Biomedical Science Center for Translational Research, The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan.|Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mizuno
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D045744:Cell Line, Tumor; D004283:Dog Diseases / Q000188:drug therapy; D004285:Dogs; D008247:Lysosomes / Q000187:drug effects*; D008545:Melanoma / Q000188:drug therapy* / Q000662:veterinary; D018613:Microscopy, Confocal; D009570:Nitriles / Q000494:pharmacology*; D000090063:Proto-Oncogene Mas; D011804:Quinolines / Q000494:pharmacology*; D019061:src-Family Kinases / Q000037:antagonists & inhibitors*
chemical_list: D000814:Aniline Compounds; C000715470:MAS1 protein, human; D009570:Nitriles; D000090063:Proto-Oncogene Mas; D011804:Quinolines; C471992:bosutinib; D019061:src-Family Kinases; D020169:Caspases
keywords: 
  SRC inhibitor; blockage of autophagy flux; caspase-independent cell death; cathepsin B; lysosomal membrane permeabilization; melanoma