The prevention of the staurosporine-induced apoptosis by Bcl-X(L), but not by Bcl-2 or caspase inhibitors, allows the extensive differentiation of human neuroblastoma cells.
Staurosporine is one of the best apoptotic inducers in different cell types including neuroblastomas. In this study we have compared the efficiency and final outcome of three different anti-apoptotic strategies in staurosporine-treated SH-SY5Y human neuroblastoma cells. At staurosporine concentrations up to 500 nm, z-VAD.fmk a broad-spectrum, noncompetitive inhibitor of caspases, reduced apoptosis in SH-SY5Y cells. At higher concentrations, z-VAD.fmk continued to inhibit caspases and the apoptotic phenotype but not cell death which seems to result from oxidative damage. Stable over-expression of Bcl-2 in SH-SY5Y protected cells from death at doses of staurosporine up to 1 microm. At higher doses, cytochrome c release from mitochondria occurred, caspases were activated and cells died by apoptosis. Therefore, we conclude that Bcl-2 increased the threshold for apoptotic cell death commitment. Over-expression of Bcl-X(L) was far more effective than Bcl-2. Bcl-X(L) transfected cells showed a remarkable resistance staurosporine-induced cytochrome c release and associated apoptotic changes and survived for up to 15 days in 1 microm staurosporine. In these conditions, SH-SY5Y displayed a remarkable phenotype of neuronal differentiation as assessed by neurite outgrowth and expression of neurofilament, Tau and MAP-2 neuronal specific proteins.
Yuste
Víctor J
VJ
Grup de Neurobiologia Molecular, Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain.
Sánchez-López
Isabel
I
Solé
Carme
C
Encinas
Mario
M
Bayascas
Jose R
JR
Boix
Jacint
J
Comella
Joan X
JX
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D061945:Caspase Inhibitors; D002454:Cell Differentiation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D016501:Neurites / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D009447:Neuroblastoma / Q000473:pathology* / Q000503:physiopathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000494:pharmacology*; D019311:Staurosporine / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D051020:bcl-X Protein
D000590:Amino Acid Chloromethyl Ketones; C494811:BCL2L1 protein, human; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D019311:Staurosporine