Induction of apoptosis by hinokitiol, a potent iron chelator, in teratocarcinoma F9 cells is mediated through the activation of caspase-3

Cell Prolif. 1999 Feb;32(1):63-73. doi: 10.1046/j.1365-2184.1999.3210063.x.


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.

MeSH terms

  • Amino Acid Chloromethyl Ketones / pharmacology
  • Aniline Compounds / pharmacology
  • Apoptosis / drug effects*
  • Caspase 3
  • Caspases / metabolism*
  • Cell-Free System
  • Cysteine Proteinase Inhibitors / pharmacology
  • DNA Fragmentation
  • Embryonal Carcinoma Stem Cells
  • Enzyme Activation / drug effects
  • Enzyme Activation / physiology
  • Iron Chelating Agents / pharmacology*
  • Monoterpenes*
  • Neoplastic Stem Cells / cytology
  • Neoplastic Stem Cells / drug effects*
  • Neoplastic Stem Cells / enzymology
  • Oligopeptides / pharmacology
  • Teratocarcinoma*
  • Tropolone / analogs & derivatives*
  • Tropolone / pharmacology


  • Amino Acid Chloromethyl Ketones
  • Aniline Compounds
  • Cysteine Proteinase Inhibitors
  • Iron Chelating Agents
  • Monoterpenes
  • Oligopeptides
  • acetyl-aspartyl-glutamyl-valyl-aspartal
  • benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone
  • L 709049
  • nitroaniline
  • Tropolone
  • Caspase 3
  • Caspases
  • beta-thujaplicin