title: Both calcium and ROS as common signals mediate Na(2)SeO(3)-induced apoptosis in SW480 human colonic carcinoma cells.
abstract: Recent studies have shown that reactive oxygen species (ROS) play a crucial role in Se-induced cell apoptosis. A number of studies have demonstrated that perturbed cellular calcium homeostasis has been implicated in apoptosis. The main objective of this study was to evaluate the role of Ca(2+) in Na(2)SeO(3)-induced apoptosis and the relationship between Ca(2+) and ROS in human colonic carcinoma cells SW480. When SW480 cells were exposed to 25-100 microM Na(2)SeO(3), both cell apoptosis and growth inhibition were observed by flow cytometric analysis and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Na(2)SeO(3) was able to induce increase of [Ca(2+)](i) and ROS production and disrupt mitochondrial membrane potential (Delta Psi m) in SW480 cells monitored by using a confocal laser scanning microscope. Ca(2+) channel inhibitor CoCl(2) and an intracellular Ca(2+) chelator o-phtalaldehyde, 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid acetoxymethyl ester (BAPTA) completely inhibited [Ca(2+)](i) increase, but catalase had no effect on Na(2)SeO(3)-induced increase of [Ca(2+)](i). BAPTA-AM, CoCl(2), and mitochondrial Ca(2+) uptake inhibitor ruthenium red blocked Delta Psi m dissipation. The increase of ROS was also suppressed by CoCl(2), BAPTA, ruthenium red, N-acetylcysteine and catalase, respectively. The mitochondrial uncoupler carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) completely inhibited Na(2)SeO(3)-induced ROS increase. This showed that ROS increase is due to mitochondrial Ca(2+) overload. The Na(2)SeO(3)-induced apoptosis of SW480 cells was also inhibited by CoCl(2), BAPTA, ruthenium red, N-acetylcysteine, and catalase, respectively. The results mentioned above imply that both calcium and Ca(2+)-dependent ROS as a signal molecule mediate apoptosis induced by Na(2)SeO(3) in SW480 cells.
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000814:Aniline Compounds / Q000032:analysis / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002118:Calcium / Q000032:analysis / Q000502:physiology*; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D045744:Cell Line, Tumor / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003035:Cobalt / Q000494:pharmacology; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D053938:DNA Fragmentation / Q000187:drug effects; D004229:Dithiothreitol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D005434:Flow Cytometry; D005452:Fluoresceins / Q000032:analysis / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism*; D012430:Ruthenium Red / Q000494:pharmacology; D018038:Sodium Selenite / Q000494:pharmacology*; D014966:Xanthenes / Q000032:analysis / Q000494:pharmacology
chemical_list: D000814:Aniline Compounds; D005452:Fluoresceins; D017382:Reactive Oxygen Species; D014966:Xanthenes; D012430:Ruthenium Red; C029569:diacetyldichlorofluorescein; C059715:Fluo-3; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D003035:Cobalt; D004533:Egtazic Acid; D002374:Catalase; C018021:cobaltous chloride; D005978:Glutathione; D018038:Sodium Selenite; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium; D004229:Dithiothreitol; D000111:Acetylcysteine