Aminoflavone induces oxidative DNA damage and reactive oxidative species-mediated apoptosis in breast cancer cells

Int J Cancer. 2008 Apr 1;122(7):1665-74. doi: 10.1002/ijc.23244.


Aminoflavone (5-amino-2-(4-amino-3-fluorophenyl)-6,8-difluoro-7-methylchromen-4-one; AF; NSC 686288), a novel anticancer candidate agent, is undergoing clinical evaluation. AF induces DNA-protein cross-links (DPCs), Gamma-H2AX phosphorylation, aryl hydrocarbon receptor (AhR) signaling, apoptosis and its own metabolism via cytochrome P4501A1 and 1A2 (CYP1A1/1A2) activation in sensitive estrogen receptor positive (ER+) MCF7 breast cancer cells. Estrogen receptor negative (ER-) breast cancer is typically more aggressive with a poorer prognosis. In this investigation, we evaluated the ability of AF to induce reactive oxygen species (ROS) formation, oxidative DNA damage and apoptosis in ER- MDA-MB-468 breast cancer cells. The antioxidant, N-acetyl-L-cysteine (NAC), attenuated the cytotoxic effects of AF in MDA-MB-468 cells; an effect is also observed in ER+ T47D breast cancer cells. Nonmalignant MCF10A breast epithelial cells were resistant to the cytotoxic effects of AF. AF increased intracellular ROS, an effect blocked by NAC and the CYP1A1/1A2 inhibitor, alpha-Naphthoflavone (alpha-NF). AF induced oxidative DNA damage as evidenced by increased 8-oxo-7,8-dihydroguanine (8-oxodG) levels and DPC formation in these cells. AF caused S-phase arrest corresponding to an increase in p21((waf1/cip1)) protein expression. AF induced caspase 3, 8 and 9 activation, caspase-dependent apoptotic body formation and poly [ADP-ribose] polymerase (PARP) cleavage. Pretreatment with the pan-caspase inhibitor, benzyloxycarbonyl-Val-Ala-DL-Asp(OMe)-fluoromethylketone inhibited apoptosis and partially inhibited ROS formation and oxidative DNA damage. Pretreatment with NAC attenuated AF-induced apoptotic body formation and caspase 3 activation. These studies suggest AF inhibits the growth of breast cancer cells in part, by inducing ROS production, oxidative DNA damage and apoptosis and has the potential to treat hormone-independent breast cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Acetylcysteine / pharmacology
  • Antineoplastic Agents / antagonists & inhibitors
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Blotting, Western
  • Breast Neoplasms / chemistry
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / pathology*
  • Caspases / metabolism
  • Cytochrome P-450 CYP1A1 / metabolism
  • Cytochrome P-450 CYP1A2 / metabolism
  • DNA Damage / drug effects*
  • DNA, Neoplasm / drug effects*
  • Enzyme Activation / drug effects
  • Female
  • Flavonoids / antagonists & inhibitors
  • Flavonoids / pharmacology*
  • Free Radical Scavengers / pharmacology
  • Humans
  • Reactive Oxygen Species / metabolism*
  • Receptors, Estrogen / analysis
  • S Phase / drug effects


  • Antineoplastic Agents
  • DNA, Neoplasm
  • Flavonoids
  • Free Radical Scavengers
  • Reactive Oxygen Species
  • Receptors, Estrogen
  • aminoflavone
  • Cytochrome P-450 CYP1A1
  • Cytochrome P-450 CYP1A2
  • Caspases
  • Acetylcysteine