Involvement of protein kinase C-regulated ceramide generation in inostamycin-induced apoptosis

Makoto Kawatani, Siro Simizu, Hiroyuki Osada, Minoru Takada, Nadir Arber, Masaya Imoto

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Activation of caspases is commonly involved in the apoptosis induced by various anticancer drugs. However, the upstream events leading to the activation of caspases seem to be specific to each anticancer drug. In the present study, we examined the possible involvement of protein kinase C (PKC) and ceramide generation in caspase-3(-like) protease activation induced by inostamycin, a phosphatidylinositol synthesis inhibitor. Treatment of cells with 12-O-tetradecanoyl phorbol-13-acetate (TPA), an activator of PKC, suppressed the release of cytochrome c from mitochondria and the activation of caspase-3(-like) proteases in inostamycin-treated cells, but not in other anticancer drug-treated cells. Inostamycin induced the elevation of intracellular ceramide levels, and fumonisin B1, an inhibitor of ceramide synthase, inhibited inostamycin-induced cytochrome c release, caspase-3(-like) protease activation, and apoptosis. Moreover, TPA also inhibited inostamycin-induced ceramide synthesis. Taken together, our results suggest that inostamycin-induced apoptosis is mediated by PKC-regulated ceramide generation, leading to the activation of a caspase cascade. (C) 2000 Academic Press.

Original languageEnglish
Pages (from-to)389-397
Number of pages9
JournalExperimental Cell Research
Issue number2
Publication statusPublished - 2000 Sept 15
Externally publishedYes

ASJC Scopus subject areas

  • Cell Biology


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