Vitamin C protects HL60 and U266 cells from arsenic toxicity Journal Article
| Authors: | Karasavvas, N.; Cárcamo, J. M.; Stratis, G.; Golde, D. W. |
| Article Title: | Vitamin C protects HL60 and U266 cells from arsenic toxicity |
| 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 (As2O 3) 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 As 2O3 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. © 2005 by The American Society of Hematology. |
| Keywords: | controlled study; human cell; cell viability; apoptosis; cytotoxicity; cell line, tumor; arsenic trioxide; reactive oxygen species; reactive oxygen metabolite; hydrogen peroxide; ascorbic acid; cell protection; dehydroascorbic acid; copper; biological transport; oxidation-reduction; glutathione; colony formation; arsenic; chelating agent; buffer; cell-free system; hl-60 cells; cell volume; cell strain hl 60; iron chelating agent |
| Journal Title: | Blood |
| Volume: | 105 |
| Issue: | 10 |
| ISSN: | 0006-4971 |
| Publisher: | American Society of Hematology |
| Date Published: | 2005-05-15 |
| Start Page: | 4004 |
| End Page: | 4012 |
| Language: | English |
| DOI: | 10.1182/blood-2003-03-0772 |
| PUBMED: | 15677571 |
| PROVIDER: | scopus |
| PMCID: | PMC1895087 |
| DOI/URL: | |
| Notes: | --- - "Cited By (since 1996): 29" - "Export Date: 24 October 2012" - "CODEN: BLOOA" - "Source: Scopus" |
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
Related MSK Work