Figure 4.

Propidium iodide uptake assay of glioma cell sensitivity to combination treatments. Cells from the indicated early passage glioma cell lines or ex vivo gliomas were incubated in vitro with soluble TRAIL at 100 ng ml⁻¹ (+) or 1000 ng ml⁻¹ (++) alone or together with temozolomide (13.7 μg ml⁻¹) or cisplatin (54 μg ml⁻¹) for 48 h. Flow cytometry measurement of propidium iodide exclusion was used to quantitate the proportion of surviving cells. The areas of the circles denote survival following each treatment. Small circles indicate efficient killing, large circles reflect survival.