Implication of mitochondria-derived reactive oxygen species, cytochrome C and caspase-3 in N-(4-hydroxyphenyl)retinamide-induced apoptosis in cervical carcinoma cells

Oncogene. 1999 Nov 4;18(46):6380-7. doi: 10.1038/sj.onc.1203024.


N-(4-Hydroxyphenyl)retinamide (4HPR) is currently used in cancer prevention and therapy trials. It is thought that its effects result from induction of apoptosis. 4HPR-induced apoptosis in human cervical carcinoma C33A cells involves enhanced generation of reactive oxygen species (ROS). In this study we explored the mechanism by which 4HPR increases ROS and induces apoptosis in these cells. 4HPR induced cytochrome c release from mitochondria to cytoplasm, activated caspase-3, and caused a membrane permeability transition (MPT). All these 4HPR's effects, as well as the induction of apoptosis, were inhibited by antioxidants, which decrease ROS. Thenoyltrifluoroacetone, a mitochondrial respiratory chain (MRC) complex II inhibitor, and carbonylcyanide m-chlorophenyl hydrazone, which uncouples electron transfer and ATP synthesis and inhibits ROS generation by MRC, inhibited 4HPR-induced ROS generation very effectively. Rotenone, an MRC complex I inhibitor was less effective and azide, an MRC complex IV inhibitor, exhibited a marginal effect. In contrast, antimycin A, an MRC complex III inhibitor, enhanced 4HPR-induced ROS generation. These findings suggest that 4HPR enhances ROS generation by affecting a target between complex II and complex III, presumably coenzyme Q. This effect is followed by release of cytochrome c, increased caspase-3 activity, induction of MPT and eventual DNA fragmentation and cell death.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anticarcinogenic Agents / pharmacology*
  • Antimycin A / pharmacology
  • Antineoplastic Agents / pharmacology*
  • Antioxidants / pharmacology
  • Apoptosis / drug effects*
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / analogs & derivatives
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Carcinoma, Squamous Cell / pathology*
  • Caspase 3
  • Caspases / physiology*
  • Cytochrome c Group / physiology*
  • Electron Transport / drug effects
  • Electron Transport Complex I
  • Electron Transport Complex II
  • Electron Transport Complex III / antagonists & inhibitors
  • Enzyme Inhibitors / pharmacology
  • Female
  • Fenretinide / pharmacology*
  • Humans
  • Mitochondria / metabolism*
  • Multienzyme Complexes / antagonists & inhibitors
  • NADH, NADPH Oxidoreductases / antagonists & inhibitors
  • Neoplasm Proteins / physiology*
  • Oxidoreductases / antagonists & inhibitors
  • Reactive Oxygen Species*
  • Rotenone / pharmacology
  • Sodium Azide / pharmacology
  • Succinate Dehydrogenase / antagonists & inhibitors
  • Thenoyltrifluoroacetone / pharmacology
  • Tumor Cells, Cultured / drug effects
  • Uncoupling Agents / pharmacology
  • Uterine Cervical Neoplasms / pathology*


  • Anticarcinogenic Agents
  • Antineoplastic Agents
  • Antioxidants
  • Cytochrome c Group
  • Enzyme Inhibitors
  • Multienzyme Complexes
  • Neoplasm Proteins
  • Reactive Oxygen Species
  • Uncoupling Agents
  • Rotenone
  • Fenretinide
  • Thenoyltrifluoroacetone
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • Antimycin A
  • Sodium Azide
  • Oxidoreductases
  • Electron Transport Complex II
  • Succinate Dehydrogenase
  • NADH, NADPH Oxidoreductases
  • CASP3 protein, human
  • Caspase 3
  • Caspases
  • Electron Transport Complex I
  • Electron Transport Complex III