title: Involvement of PAR-4 in cannabinoid-dependent sensitization of osteosarcoma cells to TRAIL-induced apoptosis.
abstract: The synthetic cannabinoid WIN 55,212-2 is a potent cannabinoid receptor agonist with anticancer potential. Experiments were performed to determine the effects of WIN on proliferation, cell cycle distribution, and programmed cell death in human osteosarcoma MG63 and Saos-2 cells. Results show that WIN induced G2/M cell cycle arrest, which was associated with the induction of the main markers of ER stress (GRP78, CHOP and TRB3). In treated cells we also observed the conversion of the cytosolic form of the autophagosome marker LC3-I into LC3-II (the lipidated form located on the autophagosome membrane) and the enhanced incorporation of monodansylcadaverine and acridine orange, two markers of the autophagic compartments such as autolysosomes. WIN also induced morphological effects in MG63 cells consisting in an increase in cell size and a marked cytoplasmic vacuolization. However, WIN effects were not associated with a canonical apoptotic pathway, as demonstrated by the absence of specific features, and only the addition of TRAIL to WIN-treated cells led to apoptotic death probably mediated by up-regulation of the tumor suppressor factor PAR-4, whose levels increased after WIN treatment, and by the translocation of GRP78 on cell surface.
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Notaro
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Selenia
authors.initials: S
authors.lastname: Sabella
authors.affiliation: 2. Laboratory of Cellular and Developmental Genetics, Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec, Canada.
authors.forename: Ornella
authors.initials: O
authors.lastname: Pellerito
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Di Fiore
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: De Blasio
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Renza
authors.initials: R
authors.lastname: Vento
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Calvaruso
authors.affiliation: 1. Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Giuliano
mesh_terms: D000165:Acridine Orange; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D048588:Benzoxazines / Q000494:pharmacology*; D002103:Cadaverine / Q000031:analogs & derivatives; D063386:Cannabinoid Receptor Agonists / Q000494:pharmacology*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology*; D009281:Naphthalenes / Q000494:pharmacology*; D012516:Osteosarcoma / Q000188:drug therapy / Q000503:physiopathology*; D034741:RNA, Small Interfering / Q000235:genetics; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; D048588:Benzoxazines; D063386:Cannabinoid Receptor Agonists; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D009025:Morpholines; D009281:Naphthalenes; D034741:RNA, Small Interfering; D053221:TNF-Related Apoptosis-Inducing Ligand; C101296:prostate apoptosis response-4 protein; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D000165:Acridine Orange; C008542:monodansylcadaverine; D002103:Cadaverine
keywords: Cannabinoids; ER stress; GRP78/PAR-4 complex.; TRAIL; autophagy; osteosarcoma cells