Induction of apoptosis by tocotrienol in rat hepatoma dRLh-84 cells

Anticancer Res. 2004 May-Jun;24(3a):1683-8.

Abstract

Our aim was to evaluate the antitumor activities of tocopherol (Toc) and tocotrienol (T3) derivatives. At first, we examined the effect of these vitamin E homologues on the proliferation of rat normal hepatocyte RLN-10 and hepatoma dRLh-84 cells and found that especially T3 inhibited cell proliferation in dRLh-84 cells. Then, we examined the effect of vitamin E homologues on apoptosis induction and found that T3 induced DNA fragmentation and stimulated a rise of caspase-3 activity. In addition, T3 stimulated a rise in caspase-8 activity, while a caspase-8 inhibitor suppressed apoptosis induction by T3. We also examined the incorporation of vitamin E homologues into dRLh-84 cells. T3 was incorporated more quickly compared to Toc. These results indicated that T3 induces apoptosis in dRLh-84 cells and that caspase-8 is involved in this apoptosis induction. The difference in terms of apoptosis induction by vitamin E homologues seems to be related to their different rates of cellular incorporation.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Caspase 3
  • Caspase 8
  • Caspase Inhibitors
  • Caspases / metabolism
  • Cell Division / drug effects
  • Cell Line, Tumor
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology
  • Liver Neoplasms, Experimental / drug therapy*
  • Liver Neoplasms, Experimental / enzymology
  • Liver Neoplasms, Experimental / pathology
  • Oligopeptides / pharmacology
  • Rats
  • Tocopherols / pharmacology
  • Tocotrienols / pharmacology*
  • Vitamin E / analogs & derivatives
  • Vitamin E / pharmacology

Substances

  • Caspase Inhibitors
  • Enzyme Inhibitors
  • Oligopeptides
  • Tocotrienols
  • benzyloxycarbonyl-isoleucyl-glutamyl-threonyl-aspartic acid fluoromethyl ketone
  • Vitamin E
  • Casp3 protein, rat
  • Casp8 protein, rat
  • Caspase 3
  • Caspase 8
  • Caspases
  • Tocopherols