Cancer Chemotherapy and Pharmacology

, Volume 54, Issue 4, pp 315–321

Ascorbate modulation of H2O2 and camptothecin-induced cell death in Jurkat cells

  • Alain-Théophile Sané
  • André M. Cantin
  • Benoit Paquette
  • J. Richard Wagner
Original Article

DOI: 10.1007/s00280-004-0828-8

Cite this article as:
Sané, A., Cantin, A.M., Paquette, B. et al. Cancer Chemother Pharmacol (2004) 54: 315. doi:10.1007/s00280-004-0828-8

Abstract

The effect of ascorbate on cell death was examined in Jurkat cells (human T-cell leukemia) by incubation with dehydroascorbate (DHA), which is rapidly taken up by cells and efficiently reduced to ascorbate. Apoptosis was evaluated by caspase-3 activity in cell extracts and flow cytometry of annexin V-labeled cells. In parallel, necrosis was estimated by the release of lactate dehydrogenase. Minor effects on cell death were observed when Jurkat cells were incubated with either DHA alone (100–1,000 μM) or a single dose of 10 μM H2O2. However, pre-incubation with DHA followed by exposure to H2O2 clearly stimulated both apoptosis and necrosis. In complete contrast, pre-incubation of cells with DHA significantly inhibited apoptosis, but did not affect necrosis, induced by the topoisomerase I inhibitor camptothecin. Our results indicate that intracellular ascorbate can modulate cell death in a manner which depends upon the nature of the apoptotic stimulus, which in turn has critical implications regarding the mechanism and potential application of ascorbate in cancer therapy.

Keywords

DehydroascorbateReactive oxygen speciesTopoisomerase inhibitors

Abbreviations

CPT

20-S-camptothecin lactone

DHA

Dehydroascorbate

LDH

Lactate dehydrogenase

Ac-DEVD-AMC

Ac-Asp-Glu-Val-Asp-amino-4-methylcoumarin

PS

Phosphatidylserine

GSH

Glutathione

DTT

Dithiothreitol

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Alain-Théophile Sané
    • 1
  • André M. Cantin
    • 2
  • Benoit Paquette
    • 3
  • J. Richard Wagner
    • 1
    • 3
  1. 1.Centre de recherche sur le vieillissementInstitut Universitaire de Gériatrie de SherbrookeSherbrookeCanada
  2. 2.Unité de recherche pulmonaireCentre Hospitalier Universitaire de SherbrookeSherbrookeCanada
  3. 3.Département de médecine nucléaire et radiobiologie, Faculté de MédecineUniversité de SherbrookeSherbrookeCanada