Ca2+ mobilization during cell death induction by sodium 5, 6-benzylidene-L-ascorbate

Area of Science:

• Biochemistry
• Cell Biology
• Oncology

Background:

• Glutathione depletion can sensitize cancer cells to cytotoxic agents.
• Calcium signaling plays a critical role in cellular processes, including apoptosis.
• Sodium 5,6-benzylidene-L-ascorbate (SBA) exhibits cytotoxic effects on cancer cells.

Purpose of the Study:

• To investigate the effect of L-buthionine-[S, R]-sulfoximine (BSO) on the cytotoxic activity of SBA against human glioma and glioblastoma cell lines.
• To elucidate the role of intracellular calcium and glutathione in SBA-induced cell death.

Main Methods:

• Cell culture of human KG-1-C glioma and T98G glioblastoma cell lines.
• Treatment with SBA and BSO, a glutathione-depleting agent.
• Assessment of cytotoxicity, DNA fragmentation, and intracellular free Ca2+ concentrations using techniques like confocal microscopy with Fluo-3 fluorescence.

Main Results:

• BSO pretreatment augmented the cytotoxic activity of SBA against both cell lines.
• SBA treatment induced cell shrinkage and large DNA fragments, but not internucleosomal fragmentation.
• SBA rapidly elevated intracellular free Ca2+ concentrations, an effect further enhanced by BSO.
• Confocal microscopy revealed SBA-induced Ca2+ elevation primarily in the nuclear region.

Conclusions:

• Nuclear calcium accumulation is a critical initial step in SBA-induced cell death.
• BSO enhances SBA cytotoxicity by further increasing intracellular calcium levels.
• The findings suggest a potential therapeutic strategy combining SBA with glutathione-depleting agents for glioma and glioblastoma treatment.