title: Effect of selenium compounds and thiols on human mammary tumor cells.
abstract: The effect on cell viability and growth rate of sodium selenite, selenocystine, sodium selenate, and selenomethionine at selenium concentrations of 6.25 and 12.5 uM was studied in vitro on cells of the human mammary tumor cell line HTB123/DU4475. Selenite and selenocystine affected both cell viability and growth rate of the tumor cells at these selenium concentrations. Selenite and selenocystine decreased intracellular glutathione concentrations, but did not affect tumor cell glutathione peroxidase activity. After six days of exposure to either selenate or selenomethionine, the viability of tumor cells remained stable, but cell growth, as measured by numbers of cells, was retarded. Neither selenate nor selenomethionine produced changes in concentrations of intracellular glutathione. The toxic effect of selenite on tumor cells was enhanced by addition of 0.25 mM glutathione to the growth medium. Preincubation of the tumor cells with 62.5 uM buthionine sulfoximine decreased cellular glutathione to 15% of controls at 24 h and enhanced the toxicity of selenite toward the tumor cells. Glutathione, 2-mercaptoethanol, and L-cysteine were all toxic to the tumor cells in a dose-dependent manner.
authors.affiliation: Center for Food and Nutrition, Texas Tech University, Lubbock 79409.
authors.forename: L
authors.initials: L
authors.lastname: Yan
authors.forename: J A
authors.initials: JA
authors.lastname: Yee
authors.forename: L M
authors.initials: LM
authors.lastname: Boylan
authors.forename: J E
authors.initials: JE
authors.lastname: Spallholz
mesh_terms: D000368:Aged; D000963:Antimetabolites / Q000494:pharmacology; D001943:Breast Neoplasms / Q000201:enzymology / Q000473:pathology*; D019328:Buthionine Sulfoximine; D002470:Cell Survival / Q000187:drug effects; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005978:Glutathione / Q000378:metabolism / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D008623:Mercaptoethanol / Q000494:pharmacology; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D016566:Organoselenium Compounds / Q000494:pharmacology*; D064586:Selenic Acid; D020887:Selenious Acid; D012643:Selenium / Q000494:pharmacology*; D018036:Selenium Compounds; D017279:Selenocysteine; D012645:Selenomethionine / Q000494:pharmacology; D018038:Sodium Selenite; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D014343:Trypan Blue; D014407:Tumor Cells, Cultured
chemical_list: D000963:Antimetabolites; D016566:Organoselenium Compounds; D018036:Selenium Compounds; D013438:Sulfhydryl Compounds; D017279:Selenocysteine; D008717:Methionine Sulfoximine; D019328:Buthionine Sulfoximine; D008623:Mercaptoethanol; D012645:Selenomethionine; D005979:Glutathione Peroxidase; D020887:Selenious Acid; D005978:Glutathione; D012643:Selenium; D018038:Sodium Selenite; D064586:Selenic Acid; D014343:Trypan Blue; D003545:Cysteine