Diphenyl diselenide induces apoptotic cell death and modulates ERK1/2 phosphorylation in human neuroblastoma SH-SY5Y cells

Diphenyl diselenide (PhSe)(2) is a synthetic organoselenium compound displaying glutathione peroxidase-like activity. Protective and antioxidant potential of (PhSe)(2) have been extensively investigated in in vivo and in vitro studies. In spite of this, there is a lack of studies addressed to the investigation of potential cytotoxic effect and signaling pathways modulated by this compound. Herein, we aimed to analyze the effects of 24-h treatment with (PhSe)(2) on cell viability and a possible modulation of signaling pathways in human neuroblastoma cell line SH-SY5Y. For this purpose, cells were incubated with (PhSe)(2) (0.3-30 mu M) for 24 h and cell viability, apoptotic cell death and modulation of MAPKs (ERK1/2 and p38(MAPK)), and PKC substrates phosphorylation was determined. (PhSe)(2) treatment significantly decreased cell viability and increased the number of apoptotic cells with induction of PARP cleavage. An increase in ERK1/2 phosphorylation was observed at (PhSe)(2) 3 mu M. In contrast, higher concentrations of the chalcogenide inhibited ERK1/2, p38(MAPK) and PKC substrate phosphorylation. Pre-treatment with ERK1/2 inhibitor, U0126, increased cell susceptibility to (PhSe)(2). Together, these data indicate a cytotoxic potential of (PhSe)(2) in a neuronal cell line, which appears to be mediated by the ERK1/2 pathway.