Staurosporine differentiated human SH-SY5Y neuroblastoma cultures exhibit transient apoptosis and trophic factor independence.

The use of chemically differentiated neuroblastoma cells in the study of neuronal function has become a common alternative to primary neuronal cell cultures in recent years, particularly in the area of cell death. Staurosporine, a nonselective protein kinase inhibitor, has been demonstrated to be a particularly strong inducer of differentiation in the SH-SY5Y human neuroblastoma cell line. However, at present, no data exist on the long-term effects of this compound. We have compared the effects of staurosporine with 12-O-tetradecanoyl phorbol-13 acetate and retinoic acid in terms of long-term cell viability and neuronal function in the SH-SY5Y cell line. In the presence of serum, staurosporine-treated cells underwent apoptosis, which ultimately resulted in total cell loss. In contrast, when cultured in defined serum-free medium, a cessation of apoptosis occurred after approximately 1 week, at which point viability could be maintained in excess of 1 month. The addition of aurintricarboxylic acid, which has been demonstrated to prevent apoptosis in a variety of cell models, completely prevented both apoptosis and differentiation in staurosporine-treated cells both under serum-supplemented and serum-free conditions. Apoptosis was not prevented by the protein synthesis inhibitor, cycloheximide. The removal of staurosporine from the culture medium after 3 weeks had no effect on cellular morphology, function, or proliferation, indicating that the attained neuronal phenotype was terminal. Voltage-gated calcium channel sensitivity, used as a measurement of neuronal function, was highest in staurosporine-treated cells. On the basis that apoptosis and neurotrophin independence are hallmarks of the maturation of dorsal root ganglion neurons, results suggest that staurosporine-differentiated SH-SY5Y cells may bear a similar phenotype to that found in vivo. Furthermore, this model may provide for an excellent means of obtaining a stable and homogenous population of postmitotic monoaminergic neurons for investigating neuronal function and differentiation.