title: GSK3 promotes arsenite-induced apoptosis via facilitation of mitochondria disruption.
abstract: Arsenic is an environmental toxicant that recently has been shown to have anticancer activity against a number of types of cancer cells by inducing apoptosis. Glycogen synthase kinase-3 (GSK3), a serine/threonine kinase, is an important pro-apoptotic signaling enzyme. Although GSK3 has been shown to promote apoptosis caused by a wide variety of insults, a role for GSK3 in arsenic-induced apoptosis has not yet been identified. Investigation of the involvement of GSK3 in arsenite-induced apoptosis demonstrated that arsenite induced apoptosis in SH-SY5Y human neuroblastoma cells, activating the executioner caspase-3 which caused cleavage of poly-ADP ribose-polymerase (PARP). Two selective GSK3 inhibitors, lithium and SB216763, attenuated caspase-3 activation and PARP cleavage induced by arsenite treatment indicating that GSK3 contributed to arsenite-induced apoptosis. Apoptotic signaling following exposure to arsenite involved cytochrome C release from mitochondria, and this was reduced by inhibition of GSK3 indicating that GSK3 promotes arsenite-induced apoptotic signaling upstream of mitochondrial disruption. Moreover, arsenite induced the translocation of Bax and p53 to the mitochondria and the activation-associated oligomerization of Bax, and these crucial events were reduced by inhibition of GSK3, indicating that GSK3 promotes arsenite-induced apoptosis by facilitating signals leading to mitochondrial apoptotic events. Taken together, the findings from this study reveal that GSK3 promotes arsenite-induced apoptosis by facilitating signaling leading to disruption of mitochondria.
authors.affiliation: Laboratory of Pharmacology, Chulabhorn Research Institute, Bangkok, 10210, Thailand. Piyajit@cri.or.th <Piyajit@cri.or.th>
authors.forename: Piyajit
authors.initials: P
authors.lastname: Watcharasit
authors.forename: Apinya
authors.initials: A
authors.lastname: Thiantanawat
authors.forename: Jutamaad
authors.initials: J
authors.lastname: Satayavivad
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D018053:Arsenites / Q000633:toxicity*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D018020:Lithium Compounds / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D009447:Neuroblastoma / Q000201:enzymology / Q000473:pathology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D017670:Sodium Compounds / Q000633:toxicity*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D018053:Arsenites; C494826:BAX protein, human; D007211:Indoles; D018020:Lithium Compounds; D008301:Maleimides; D047428:Protein Kinase Inhibitors; C417521:SB 216763; D017670:Sodium Compounds; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C017947:sodium arsenite; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3; C505407:CASP3 protein, human; D053148:Caspase 3