Generation of hydrogen peroxide precedes loss of mitochondrial membrane potential during DNA alkylation-induced apoptosis.

Abstract

Pulsed field gel electrophoresis showed that the initiation time of DNA breakage induced by the DNA alkylating agent duocarmycin A, which is not a redox-cycling agent, was almost the same in the human leukemia cell line HL-60 and its H2O2-resistant clone HP100. Catalase activity of HP100 cells was much higher than that of HL-60 cells. Duocarmycin A-mediated DNA ladder formation in HP100 cells was delayed compared with that in HL-60 cells, suggesting the involvement of H2O2 in duocarmycin A-induced apoptosis. Flow cytometry demonstrated that peroxide formation preceded loss of mitochondrial membrane potential (delta psi m) in cells treated with duocarmycin A. Then, caspase-3 was activated, followed by DNA ladder formation. These findings suggest that DNA damage by duocarmycin A induces H2O2 generation, which causes delta psi m loss and subsequently caspase-3 activation, resulting in apoptosis.

• Authors: S Tada-Oikawa, S Oikawa, M Kawanishi, M Yamada, S Kawanishi
• Journal: FEBS letters (FEBS Lett) Vol. 442 Issue 1 Pg. 65-9 (Jan 08 1999) ISSN: 0014-5793 [Print] England
• PMID: 9923606 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alkylating Agents
• Duocarmycins
• Indoles
• Pyrrolidinones
• DNA
• Hydrogen Peroxide
• CASP3 protein, human
• Caspase 3
• Caspases
• duocarmycin A

Topics

• Alkylating Agents (pharmacology)
• Alkylation
• Apoptosis (drug effects, physiology)
• Caspase 3
• Caspases (metabolism)
• DNA (drug effects, metabolism)
• DNA Damage
• DNA Fragmentation (drug effects)
• Drug Resistance
• Duocarmycins
• Electrophoresis, Gel, Pulsed-Field
• Enzyme Activation (drug effects)
• HL-60 Cells
• Humans
• Hydrogen Peroxide (metabolism, pharmacology)
• Indoles
• Membrane Potentials (drug effects)
• Mitochondria (drug effects, metabolism)
• Pyrrolidinones (pharmacology)