Modulation of ERK1/2 activity is crucial for sphingosine-induced death of glioma C6 cells.

In this study the contribution of the ERK1/2 pathway to sphingosine-induced death and morphological changes of the actin cytoskeleton in glioma C6 cells was investigated. Surprisingly, the level of ERK1/2 phosphorylation does not change after incubation of cells with sphingosine. Despite this, sphingosine induces rounding and detachment of cells without formation of apoptotic bodies. To shed light on this process, a specific inhibitor of ERK1/2 phosphorylation, U0126, was used. Cells incubated simultaneously with sphingosine and U0126 not only detached, but also exhibited formation of apoptotic-like blebs. These data suggest that during sphingosine-induced glioma C6 cell death apoptotic blebbing is dependent on ERK1/2 signalling and occurs only when ERK1/2 activity is decreased or abolished.