Implication of Radical Oxygen Species in Ceramide Generation, c-Jun N-Terminal Kinase Activation and Apoptosis Induced by Daunorubicin
- Véronique Mansat-De Mas1,
- Christine Bezombes1,
- Anne Quillet-Mary1,
- Ali Bettaïeb1,
- Aurélie De Thonel D’orgeix,
- Guy Laurent1,2 and
- Jean-Pierre Jaffrézou1
- 1Institut National de la Sante et de la Recherche Medicale E9910, Institut Claudius Régaud (V.M.D., C.B., A.Q.M., A.B., G.L., J.P.J.), and 2Service d’Hématologie, Centre Hospitalier Universitaire Purpan (G.L.), Toulouse, France
Abstract
Anthracyclines such as daunorubicin (DNR) generate radical oxygen species (ROS), which account, at least in part, for their cytotoxic effect. We observed that early ceramide generation (within 6–10 min) through neutral sphingomyelinase stimulation was inhibitable by the antioxidants N-acetylcysteine and pyrrolidine dithiocarbamate, which led to a decrease in apoptosis (>95% decrease in DNA fragmentation after 6 h). Furthermore, we observed that DNR triggers the c-Jun N-terminal kinase (JNK) and the transcription factor activated protein-1 through an antioxidant-inhibitable mechanism. Treatment of U937 cells with cell-permeant ceramides induced both an increase in ROS generation and JNK activation, and apoptosis, all of which were antioxidant-sensitive. In conclusion, DNR-triggered apoptosis implicates a ceramide-mediated, ROS-dependent JNK and activated protein-1 activation.
Footnotes
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Send reprint requests to: Dr. Jean-Pierre Jaffrézou, Institut National de la Sante et de la Recherche Medicale E9910, Institut Claudius Régaud, 20 rue du Pont Saint-Pierre, Toulouse Cedex, 31052 France. E-mail: jaffrezou{at}icr.fnclcc.fr
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1 This work was supported by grants from La Fédération Nationale des Centres de Lutte Contre le Cancer (J-P.J., G.L.), L’Association pour la Recherche contre le Cancer 9296 (G.L.), 9788 (J-P.J.), and by La Ligue Nationale Contre le Cancer (J-P.J.). V.M.D. is an Institut National de la Sante et de la Recherche Medicale fellow and C.B. is a recipient of a study grant from la Ligue Nationale contre le Cancer.
- Abbreviations:
- DNR
- daunorubicin
- SM
- sphingomyelin
- SMase
- sphingomyelinase
- N-SMase
- neutral magnesium-dependent sphingomyelinase
- CER
- ceramide
- TNFα
- tumor necrosis factor α
- ROS
- radical oxygen species
- PDTC
- pyrrolidine dithiocarbamate
- N-Ac
- N-acetylcysteine
- BSO
- buthionine-sulfoximine
- JNK
- c-Jun-N terminal kinase
- AP-1
- activated protein 1
- DAPI
- 4′, 6′-diamino 2-phenylindol
- DTT
- dithiothreitol
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- Received July 8, 1999.
- Accepted August 6, 1999.
- The American Society for Pharmacology and Experimental Therapeutics
