[Staurosporine inhibits enhancement of the metabolism of phospholipids induced by phorbol-ester in a manner similar to that of combined action agents with calmodulin].

Staurosporine, an antitumor-promoting agent, suppressed phorbol ester-enhanced phospholipid synthesis. The inhibitory effect of staurosporine was found to be dominant in the synthesis of phosphatidylcholine and phosphatidylethanolamine. The manner of this inhibitory action by staurosporine was similar to that of various kinds of antitumor-promoting agents, which have the ability to interact with Ca2(+)-calmodulin complex, although the effective dose of staurosporine was 1,000 times lower than these calmodulin-interacting agents. Furthermore, staurosporine was proved to interact directly with Ca2(+)-calmodulin complex. Thus, it is possible that staurosporine showed inhibitory effect on phospholipid metabolism via the modulation of Ca2(+)-calmodulin system.