Induction of apoptosis by hinokitiol, a potent iron chelator, in teratocarcinoma F9 cells is mediated through the activation of caspase-3.
Hinokitiol, a potent iron chelator, has been reported to induce differentiation in teratocarcinoma F9 cells with a reduction of viable cells. In this study, we examined the steps leading to eventual cell death by hinokitiol during differentiation. Hinokitiol induced DNA fragmentation of F9 cells in a concentration- and time-dependent manner. This effect was also observed in a cell-free system using the nuclei from intact cells and the cytosols from hinokitiol-treated cells. In contrast, hinokitiol methyl ether and hinokitiol-Fe (III) complex, which are deficient in iron-chelating activity, showed no DNA fragmentation activity in both cell culture and cell-free systems. These results suggest that iron deprivation by hinokitiol may be involved in the induction of apoptosis of F9 cells. Caspase-3, one of the key enzymes in the apoptotic cascade, was specifically activated by hinokitiol treatment, but not by the other two derivatives. In addition, its specific inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, strongly blocked hinokitiol-induced DNA fragmentation. These results indicate that iron deprivation by hinokitiol can induce apoptosis of F9 cells through the activation of caspase-3.
Ido
Y
Y
Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan.
Muto
N
N
Inada
A
A
Kohroki
J
J
Mano
M
M
Odani
T
T
Itoh
N
N
Yamamoto
K
K
Tanaka
K
K
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000814:Aniline Compounds / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002474:Cell-Free System; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D053938:DNA Fragmentation; D054278:Embryonal Carcinoma Stem Cells; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D007502:Iron Chelating Agents / Q000494:pharmacology*; D039821:Monoterpenes; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D009842:Oligopeptides / Q000494:pharmacology; D018243:Teratocarcinoma; D014334:Tropolone / Q000031:analogs & derivatives* / Q000494:pharmacology
D000590:Amino Acid Chloromethyl Ketones; D000814:Aniline Compounds; D015853:Cysteine Proteinase Inhibitors; D007502:Iron Chelating Agents; D039821:Monoterpenes; D009842:Oligopeptides; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C096429:L 709049; C008625:nitroaniline; D014334:Tropolone; D053148:Caspase 3; D020169:Caspases; C009479:beta-thujaplicin