检索策略:cancer and arsenic trioxide (("neoplasms" OR "neoplasms" OR "cancer" ) AND ("arsenic trioxide" OR "arsenic trioxide" )) AND Research Support, N I H, Extramural http://www.ncbi.nlm.nih.gov/pubmed 检索结果 115篇 pubmed_result (1) 115.txt 研究项目实例: Blood. 2005 May 15;105(10):4004-12. Epub 2005 Jan 27. Vitamin C protects HL60 and U266 cells from arsenic toxicity. Karasavvas N , Cárcamo JM , Stratis G , Golde DW . Source Memorial Sloan-Kettering Cancer Center, Box 451, 1275 York Ave, New York, NY 10021, USA. Abstract Although there is no compelling evidence that vitamin C has antitumor activity in humans, clinical trials are testing the hypothesis that ascorbic acid (AA) will enhance the efficacy of arsenic trioxide (As2O3) in myeloma. In vitro, AA cytotoxicity depends on its interaction with free transition metal ions in culture media leading to the generation of H2O2 and other reactive oxygen species (ROSs). Therefore, to circumvent the extracellular in vitro pro-oxidant effects of AA, we loaded HL60, U266, and RPMI-8226 cells with vitamin C by incubation with dehydroascorbic acid (DHA). Loading cells in this manner resulted in prominent, dose-dependent protection of As2O3-treated cells as measured by viability, colony formation, and apoptosis assays. Glutathione depletion enhanced cell sensitivity to the cytotoxic effects of As2O3 and vitamin C loading provided protection. AA was found to generate cytotoxic concentrations of H2O2 in culture medium without cells and copper/iron chelators inhibited this reaction. However, AA did not generate H2O2 in simple buffer or human plasma. Direct incubation with AA resulted in increased intracellular ROSs, whereas DHA incubation decreased it. These results clarify an apparent paradox and indicate that vitamin C loading in HL60, U266, and RPMI-8226 cells ameliorates As2O3 cytotoxicity. PMID:15677571 PMCID:PMC1895087 Free PMC Article Images from this publication. See all images (7) Free text The following toggler user interface control may not be accessible. Tab to the next button to revert the control to an accessible version. Destroy user interface control Publication Types, MeSH Terms, Substances, Grant Support Publication Types Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. MeSH Terms Arsenic/metabolism Arsenic/toxicity* Ascorbic Acid/metabolism Ascorbic Acid/pharmacology* Biological Transport Cell Line, Tumor Cell-Free System Glutathione/metabolism HL-60 Cells Humans Hydrogen Peroxide/metabolism Oxidation-Reduction Reactive Oxygen Species/metabolism Substances Reactive Oxygen Species Ascorbic Acid Glutathione Arsenic Hydrogen Peroxide Grant Support R01 CA30388/CA/NCI NIH HHS/United States The following toggler user interface control may not be accessible. Tab to the next button to revert the control to an accessible version. Destroy user interface control LinkOut - more resources Full Text Sources HighWire Europe PubMed Central PubMed Central Medical Arsenic - MedlinePlus Health Information Vitamin C - MedlinePlus Health Information Molecular Biology Databases ARSENIC, ELEMENTAL - HSDB HYDROGEN PEROXIDE - HSDB ASCORBIC ACID - HSDB SODIUM ASCORBATE - HSDB