Depletion of Endogenous Zinc Stores Induces Oxidative Stress and Cell Death in Human Melanoma Cells

Abstract

The role of intracellular free zinc and its chelation by TPEN (N,N,N’,N’-tetrakis(2–pyridylmethyl)ethylenediamine) was studied in Bowes human melanoma cells. The content of free Zn pools was determined by fluorescent probe Zinquin. Depletion of zinc triggered apoptosis confirmed by cell blebbing, changes in mitochondrial transmembrane potential and GSH levels, caspase-3 activation and nuclear fragmentation. Apoptosis was only partially prevented by cyclosporin A or N-acetylcystein, suggesting various independent but likely interrelated mechanisms participating in this process.

Keywords

• Human melanoma cells
• Labile zinc
• Cell death
• Mitochondria
• Oxidative stress