Sulofenur cytotoxicity and changes in cytosolic calcium and mitochondrial membrane potential in human colon adenocarcinoma cell lines.

Sulofenur treatment (12.5 microM-1 mM) of colon adenocarcinoma cell lines resulted in dose- and time-dependent cell killing. LYc5 cells were viable longer than GC3/c1 cells. Each concentration resulted in elevation of cytosolic calcium [Ca2+]i) for both cell lines. At lower doses, elevation was delayed for LYc5 cells. GC3/c1 cells after 1 mM treatment in Ca(2+)-free HBSS showed no rise of [Ca2+]i. GC3/c1 cells after carbonyl cyanide-m-chlorophenylhydrazone rapidly lost rhodamine 123 fluorescence from mitochondria; after 1 mM sulofenur, fluorescence faded slowly. Following treatment, cells became rounded, blebs formed and the cells died. Results suggest that elevated [Ca2+]i plays an important role in sulofenur cytotoxicity.