title: Interaction between ERK and GSK3beta mediates basic fibroblast growth factor-induced apoptosis in SK-N-MC neuroblastoma cells.
abstract: The Ewing's sarcoma family of tumors (ESFT) includes Ewing's sarcoma (ES), Askin's tumor of the chest wall, and peripheral primitive neuroectodermal tumor. Basic fibroblast growth factor (FGF2) suppresses the growth of ESFT cells and causes their apoptosis. The underlying mechanism is unclear. Using a human peripheral primitive neuroectodermal tumor cell line, SK-N-MC, we demonstrated FGF2 stimulated phosphorylation of ERK1 and ERK2 (pERK1/2) and GSK3beta (pGSK3beta(Tyr-216)), all of which were primarily retained in the cytoplasm. FGF2 promoted the association between ERK and pGSK3beta(Tyr-216). Inhibitors for GSK3beta (TDZD and LiCl) and ERK (PD98059) protected cells from FGF2-induced apoptosis. On the other hand, inhibitors of GSK3beta, but not PD98059 decreased ERK/pGSK3beta(Tyr-216) association and caused a nuclear translocation of pERK1/2. Similarly, expression of a kinase-deficient (K85R) GSK3beta or GSK3beta-small interfering RNA inhibited FGF2-regulated ERK/pGSK3beta(Tyr-216) association and translocated pERK to the nucleus. Both K85R GSK3beta and small interfering RNA offered protection against FGF2-induced cell death. In contrast, overexpression of wild-type GSK3beta sensitized cells to FGF2 cytotoxicity. Hydrogen peroxide and ethanol enhanced FGF2-stimulated pGSK3beta(Tyr-216), ERK/pGSK3beta(Tyr-216) association, and cytoplasmic retention of pERK1/2. As a result, they potentiated FGF2-induced cell death. Taken together, our results suggested that FGF2-induced accumulation of pERK1/2 in the cytoplasm is toxic for SK-N-MC cells. The formation of an ERK.GSK3beta complex retained pERK1/2 in the cytoplasm. In contrast, disruption of the ERK.GSK3beta complex resulted in nuclear translocation of pERK1/2 and offered protection.
authors.affiliation: Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Robert C. Byrd Health Sciences Center, Morgantown, WV 26506, USA.
authors.forename: Cuiling
authors.initials: C
authors.lastname: Ma
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Bower
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Xianglin
authors.initials: X
authors.lastname: Shi
authors.forename: Zun-Ji
authors.initials: ZJ
authors.lastname: Ke
authors.forename: Jia
authors.initials: J
authors.lastname: Luo
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000494:pharmacology*; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D020125:Mutation, Missense; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D016877:Oxidants / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D034741:RNA, Small Interfering; D012512:Sarcoma, Ewing / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D012997:Solvents / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D009097:Multienzyme Complexes; D009363:Neoplasm Proteins; D016877:Oxidants; D034741:RNA, Small Interfering; D012997:Solvents; D016222:Fibroblast Growth Factor 2; D000431:Ethanol; D006861:Hydrogen Peroxide; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D038362:Glycogen Synthase Kinase 3