title: Long-term selenium supplementation in HaCaT cells: importance of chemical form for antagonist (protective versus toxic) activities.
abstract: The beneficial effect of selenium (Se) on cancer is known to depend on the chemical form, the dose and the duration of the supplementation. The aim of this work was to explore long term antagonist (antioxidant versus toxic) effects of an inorganic (sodium selenite, Na2SeO3) and an organic (seleno-L-methionine, SeMet) forms in human immortalized keratinocytes HaCaT cells. HaCaT cells were supplemented with Na2SeO3 or SeMet at micromolar concentrations for 144 h, followed or not by UVA radiation. Se absorption, effects of UVA radiation, cell morphology, antioxidant profile, cell cycle processing, DNA fragmentation, cell death triggered and caspase-3 activity were determined. At non-toxic doses (10 μM SeMet and 1 μM Na2SeO3), SeMet was better absorbed than Na2SeO3. The protection of HaCaT from UVA-induced cell death was observed only with SeMet despite both forms increased glutathione peroxidase-1 (GPX1) activities and selenoprotein-1 (SEPW1) transcript expression. After UVA irradiation, malondialdehyde (MDA) and SH groups were not modulated whatever Se chemical form. At toxic doses (100 μM SeMet and 5 μM Na2SeO3), Na2SeO3 and SeMet inhibited cell proliferation associated with S-G2 blockage and DNA fragmentation leading to apoptosis caspase-3 dependant. SeMet only led to hydrogen peroxide production and to a decrease in mitochondrial transmembrane potential. Our study of the effects of selenium on HaCaT cells reaffirm the necessity to take into account the chemical form in experimental and intervention studies.
authors.affiliation: Unité de Biochimie Hormonale et Nutritionnelle, Département de Biochimie, Toxicologie et Pharmacologie, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire de Grenoble, CS10217, 38043 Grenoble, France. FPuch@chu-grenoble.fr
authors.forename: Florence
authors.initials: F
authors.lastname: Hazane-Puch
authors.forename: Pierre
authors.initials: P
authors.lastname: Champelovier
authors.forename: Josiane
authors.initials: J
authors.lastname: Arnaud
authors.forename: Catherine
authors.initials: C
authors.lastname: Garrel
authors.forename: Bruno
authors.initials: B
authors.lastname: Ballester
authors.forename: Patrice
authors.initials: P
authors.lastname: Faure
authors.forename: François
authors.initials: F
authors.lastname: Laporte
mesh_terms: D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D002461:Cell Line, Transformed; D053938:DNA Fragmentation / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D015603:Keratinocytes / Q000378:metabolism* / Q000473:pathology; D008315:Malondialdehyde / Q000378:metabolism; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects* / Q000528:radiation effects; D012643:Selenium / Q000009:adverse effects / Q000494:pharmacology; D012645:Selenomethionine / Q000009:adverse effects / Q000494:pharmacology; D018038:Sodium Selenite / Q000009:adverse effects / Q000494:pharmacology; D014131:Trace Elements / Q000009:adverse effects / Q000494:pharmacology; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D014131:Trace Elements; D008315:Malondialdehyde; D012645:Selenomethionine; D006861:Hydrogen Peroxide; C505407:CASP3 protein, human; D053148:Caspase 3; D012643:Selenium; D018038:Sodium Selenite