The specific inhibitor of protein kinase C, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7), induces morphological change and cell differentiation of human neural crest-derived cell lineages.

It has been proved that inhibition of protein kinase C by 1-(5-isoquinolinylsulfonyl)-1-methylpiperazine (H7) induces morphological differentiation in murine neuroblastoma (nb) cell. Here we report that H7 is also active on human nb cell lines. The human nb cell had originally neuroblast-like (N) or intermediate (I) morphology. N and I type are thought to represent different stages of neuroblastoma differentiation. Neurite outgrowth was observed in N and I type morphology treating the cells with 7, 14 or 28 microM of H7. The results confirm previous observations and show that inhibition of PKC by H7 also promotes neuronal differentiation in human cell line variants.