Potentiation of temozolomide-induced cytotoxicity by pretreatment with O⁶-BeG. Male B6D2F1 mice were pretreated with either corn oil or O⁶-BeG (30 mg/kg) in corn oil and 2 hours later treated with increasing doses of temozolomide. Each data point represents the mean ± SE of at least three independent experiments. Marrows from animals were pooled in each experiment. The data were tested with analysis of variance using MINITAB statistical software. Bone marrow cellularity and numbers of GM-CFC and CFU-S following treatment with O⁶-BeG plus temozolomide (▪) were significantly (P < .001) different from temozolomide alone (•).