Copper-1,10-phenanthroline-induced apoptosis in liver carcinoma Bel-7402 cells associates with copper overload, reactive oxygen species production, glutathione depletion and oxidative DNA damage.

Abstract

The mechanism of cytotoxicity on liver carcinoma Bel-7402 cells induced by copper-1,10-phenanthroline, Cu(OP)2, has been studied. Cell viability and apoptotic rate were examined in cells treated with Cu(OP)2 or Cu2+ alone. It was found that the apoptosis induced by Cu(OP)2 could not be induced by Cu2+ or OP alone in our experimental conditions. Total copper content in cells was measured by atomic absorption spectrophotometry, and the abnormal elevation of intracellular copper transported by lipophilic OP ligand may play the role of initial factor in the apoptosis, which caused subsequent redox state changes in cells. Intracellular levels of reactive oxygen species (ROS) were detected by fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA). Reduced (GSH) and total glutathione (GSSG + GSH) were determined by High-performance liquid chromatography (HPLC) after derivatization, and the ratios of GSH/GSSG were subsequently calculated. The overproduction of ROS and the decreased GSH/GSSG ratio were observed in cells which represented the occurrence of oxidative stress in the apoptosis. Oxidative DNA damage was also found in cells treated with Cu(OP)2 in the early stage of the apoptosis, and it suggests that the activation of DNA repair system may be involved in the pathway of the apoptosis induced by Cu(OP)2.

• Authors: Xiaoqiang Cai, Nina Pan, Guolin Zou
• Journal: Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine (Biometals) Vol. 20 Issue 1 Pg. 1-11 (Feb 2007) ISSN: 0966-0844 [Print] Netherlands
• PMID: 16683182 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Neoplasm
• Organometallic Compounds
• Phenanthrolines
• Reactive Oxygen Species
• copper-1,10-phenanthroline
• Copper
• Glutathione

Topics

• Apoptosis (drug effects)
• Cell Line, Tumor
• Cell Survival (drug effects)
• Comet Assay
• Copper (metabolism)
• DNA Damage (drug effects)
• DNA, Neoplasm (genetics, metabolism)
• Dose-Response Relationship, Drug
• Flow Cytometry
• Glutathione (metabolism)
• Humans
• Liver Neoplasms (genetics, metabolism, pathology)
• Organometallic Compounds (pharmacology)
• Phenanthrolines (pharmacology)
• Reactive Oxygen Species (metabolism)
• Time Factors