Ceramide induces early and late apoptosis in human papilloma virus+ cervical cancer cells by inhibiting reactive oxygen species decay, diminishing the intracellular concentration of glutathione and increasing nuclear factor-kappaB translocation.
Ceramide is regarded as an important cellular signal for the induction of cell death. We have previously shown that ceramide induces the death of cervical tumor cells without biochemical and morphological markers of apoptosis. The mechanisms by which ceramide induces cell death are not understood, therefore we evaluated the effect of C6-ceramide, a synthetic cell-permeable analog of endogenous ceramides, in signaling pathways involved in the oxidative stress of three cervical human papilloma virus cancer cell lines. Reactive oxygen species production was determined by fluorescent 2,7-dichlorofluorescein, nitrite concentration by the Griess reaction (as an indirect measure of nitric oxide production), mitochondrial membrane potential by staining with Rh123, reduced-glutathione concentration by high-pressure liquid chromatography, nuclear factor-kappaB translocation by electrophoretic mobility shift assay, inhibitory protein of nuclear factor-kappaB expression by Western blot and cell death by a poly-caspases fluorochrome-labeled inhibitors of caspases apoptosis assay. C6-ceramide induced early and late apoptosis, which was associated with an increase in reactive oxygen species and nitric oxide production, a loss in mitochondrial membrane potential, an increase in nuclear factor-kappaB translocation, and a decrease in reduced glutathione concentration. C6-ceramide did not modify the expression of inhibitory protein of nuclear factor-kappaB and its antiproliferative effect was not abrogated by Bay 11-7082, an inhibitory protein of nuclear factor-kappaB kinase inhibitor. Our results suggest that oxidative stress might participate in the ceramide-induced damage to human papilloma virus cervical cancer cells.
Gutiérrez
Gisela
G
Department of Cell Biology, National Institute of Cardiology Ignacio Chávez, Juan Badiano No. 1, Colonia Sección 16, Tlalpan, CP 14080, Mexico DF, Mexico.
Mendoza
Criselda
C
Montaño
Luis F
LF
López-Marure
Rebeca
R
D017209:Apoptosis / Q000187:drug effects; D061945:Caspase Inhibitors; D045744:Cell Line, Tumor; D002518:Ceramides / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D009573:Nitrites / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013450:Sulfones / Q000494:pharmacology; D014178:Translocation, Genetic / Q000187:drug effects; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy* / Q000821:virology*
C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile; D061945:Caspase Inhibitors; D002518:Ceramides; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D009570:Nitriles; D009573:Nitrites; D017382:Reactive Oxygen Species; D013450:Sulfones; D005978:Glutathione