Exogenous ceramide is cytotoxic to human glioma cell lines and reduces clonogenic survival.

<p>Acute cytotoxicity was assessed 72 h after treatment with increasing concentrations of (A) C2-ceramide or (B) C6-ceramide in LNT-229 or T98G cells. For clonogenic survival data LNT-229 or T98G cells were treated with increasing concentrations of (C) C2-ceramide or (D) C6-ceramide for 24 h, then medium was changed and cells were cultured for additional 2 weeks until colonies were detectable. *, <i>p</i><0.05; **, <i>p</i><0.01; compared to untreated cells; <i>t</i>-test.