Blockage of nerve growth factor action in PC12h cells by staurosporine, a potent protein kinase inhibitor.

Staurosporine, which has a structure similar to that of K-252a, a potent protein kinase inhibitor that blocks nerve growth factor (NGF) action in PC12 and PC12h cells, is also known as a potent inhibitor of several protein kinases. This study shows that in PC12h cells staurosporine has a dual action: at lower concentrations than that required by K-252a, it is an inhibitor of NGF induction of neurite formation and of changes in the phosphorylation of specific proteins, whereas at concentrations higher than that required to inhibit NGF-induced neurite outgrowth, it rapidly enhances outgrowth by itself.