Antioxidant response induced by serum withdrawal protects HL-60 cells against inhibition of NAD(P)H:quinone oxidoreductase 1.
We have previously shown that inhibition of NAD(P)H:quinone acceptor oxidoreductase 1 with dicoumarol decreases growth and viability of HL-60 cells in the absence of serum. Here we demonstrate that culturing HL-60 cells in serum-free medium in the presence of dicoumarol results in a significant potentiation of apoptosis. However, when cells were preincubated for 24 h without serum before they were treated with dicoumarol, the effect of the inhibitor on cell growth and death was much lower. We have investigated cellular changes induced in HL-60 cells by removal of serum that could account for protection against the effects of dicoumarol. Serum removal induced significant increases of NAD(P)H:quinone acceptor oxidoreductase 1, particularly at 32 h after serum withdrawal. Total amounts of ubiquinone in cells were unchanged but, its reduction state paralleled the observed increase in quinone reductase activity. Levels of the antiapoptotic protein Bcl-2 were also significantly increased after serum removal. Our results indicate that removal of serum evokes an antioxidant protective response that make HL-60 cells less sensitive to cell death induced by inhibition of NAD(P)H:quinone acceptor oxidoreductase 1 with dicoumarol.
Gómez-Díaz
Consuelo
C
Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Spain.
Bello
Rosario I
RI
López-Lluch
Guillermo
G
Forthoffer
Nathalie
N
Navas
Plácido
P
Villalba
José M
JM
D000975:Antioxidants / Q000378:metabolism*; D017209:Apoptosis; D001769:Blood; D002455:Cell Division; D002470:Cell Survival; D016895:Culture Media, Serum-Free; D001728:Dicumarol / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010084:Oxidation-Reduction; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D014451:Ubiquinone / Q000032:analysis / Q000378:metabolism
D000975:Antioxidants; D016895:Culture Media, Serum-Free; D004791:Enzyme Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D014451:Ubiquinone; D001728:Dicumarol; D006861:Hydrogen Peroxide; D016660:NAD(P)H Dehydrogenase (Quinone)