12-O-tetradecanoyl-phorbol-13-acetate-induced differentiation of human neuroblastoma cells is not accompanied by an increase in the intracellular concentration of cyclic AMP

Human neuroblastoma cell lines as models for the in vitro study of neoplastic and neuronal cell differentiation.

“…Indeed, in leukemic cell lines, DAG inhibits DMSO-induced differentiation (130). However, inhibition of PKC alone cannot be the sole initiator of differentiation since the phorbol diester 12-0-tetradecancyl-phorbol-13-acetate, which activates PKC (131), can also induce morphologic and biochemical differentiation in some cells, including NB (132)(133)(134)(135). Further explorations in the actions of these compounds on PKC activity in NB would be of great interest.…”

Protein Kinase C-dependent Tyrosine Phosphorylation of p130 in Differentiating Neuroblastoma Cells

“…Effect of Dibutyryl cAMP on p130 cas Phosphorylation-To evaluate if activation of cyclic AMP-dependent protein kinase, in addition to PKC, promotes p130 cas phosphorylation, SH-SY5Y cells were stimulated with 1 mM dibutyryl cAMP (dbcAMP) for 5 min to 2 h. In SH-SY5Y cells, dbcAMP potentiates TPA-induced differentiation but lacks a differentiating effect when added alone (39). An increase in p130 cas tyrosine phosphorylation was seen 1 to 2 h after stimulation, but the effect was somewhat weaker and delayed compared with stimulation with TPA (Fig.…”