D -2-hydroxyglutarate toxicity and analysis of two LN229 sublines. Octyl-D-2-hydroxyglutarate mediated toxicity in different cell lines (A). D-2-hydroxyglutarate mediated toxicity in different cell lines (B). Toxicity was measured 48 h after treatment. Plotted are the relative cell numbers in % compared to the corresponding untreated control. D-2-hydroxyglutarate levels in LN229 glioma cell line and two LN229 glioma cell subclones H3 and H114 overexpressing different protein levels of R132H (C). All D-2-hydroxyglutarate levels are significantly different from each other (p ≤ 0.01). Proliferation of LN229 glioma cell line and of two LN229 glioma cell subclones H3 and H114 overexpressing different protein levels of R132H (D). The relative cell numbers were determined 48 h after seeding and are plotted in % compared to the corresponding control. The enhanced proliferation of subclone H3 is not significant compared to the parental line, but the reduced proliferation of subclone H114 is statistically significant compared to both other lines (p ≤ 0.01).