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 neuron al cell cultures in recent years, particularly in the area of cell dea th. Staurosporine, a nonselective protein kinase inhibitor, has been d emonstrated to be a particularly strong inducer of differentiation in the SH-SY5Y human neuroblastoma cell line. However, at present, no dat a exist on the long-term effects of this compound. We have compared th e effects of staurosporine with 12-O-tetradecanoyl phorbol-13 acetate and retinoic acid in terms of long-term cell viability and neuronal fu nction in the SH-SY5Y cell line. In the presence of serum, staurospori ne-treated cells underwent apoptosis, which ultimately resulted in tot al cell loss. In contrast, when cultured in defined serum-free medium, a cessation of apoptosis occurred after approximately 1 week, at whic h point viability could be maintained in excess of 1 month. The additi on of aurintricarboxylic acid, which has been demonstrated to prevent apoptosis in a variety of cell models, completely prevented both apopt osis and differentiation in staurosporine-treated cells both under ser um-supplemented and serum-free conditions. Apoptosis was not prevented by the protein synthesis inhibitor, cycloheximide. The removal of sta urosporine from the culture medium after 3 weeks had no effect on cell ular morphology, function, or proliferation, indicating that the attai ned neuronal phenotype was terminal. Voltage-gated calcium channel sen sitivity, used as a measurement of neuronal function, was highest in s taurosporine-treated cells. On the basis that apoptosis and neurotroph in independence are hallmarks of the maturation of dorsal root ganglio n neurons, results suggest that staurosporine-differentiated SH-SY5Y c ells may bear a similar phenotype to that found in vivo. Furthermore, this model may provide for an excellent means of obtaining a stable an d homogenous population of postmitotic monoaminergic neurons for inves tigating neuronal function and differentiation. (C) 1997 Elsevier Scie nce Inc.