Functional differentiation of a human ganglion cell derived neuroblastoma cell line SH-SY5Y induced by a phorbol ester (TPA).

When the human neuroblastoma cell line SH-SY5Y is exposed to 12-o-tetradecanoyl-phorbol-13-acetate (TPA) the cells grow long processes indicative of neural differentiation. Concomitantly there is an increase in the resting membrane potential from ?44 +/- 2 mV found in untreated cells to ?63 +/- 4 mV after induction. The TPA treated cells are depolarized when the external potassium concentration is increased to 46 mM and upon addition of veratridine. In contrast to the untreated cells depolarization in differentiated cells leads to an increase in the rate of Ca(2+) influx. This increase in Ca(2+) influx is blocked by the Ca(2+) channel antagonist, verapamil, while the Na(+) channel blocker tetrodotoxin only marginally inhibits the K(+) depolarization-induced Ca(2+) influx. The results suggest that the induction of morphological differentiation in this cell line is associated with the appearance of features of excitable cells.