Fig. 5

Role of MGMT in cytotoxic effects of NEO212. a, MGMT basal expression levels in TW1 and TW4 cells, compared to U251 and T98G glioblastoma cell lines, which are known to be negative and positive, respectively, for MGMT protein expression. Shown is Western blot analysis with actin as the loading control. b, TW1 and TW4 cells were pre-treated with or without 15 μM O6BG for 1 h, followed by the addition of increasing concentrations of NEO212 for 48 h. c, Cells were pre-treated with O6BG as in B, followed by the addition of cisplatin (CDDP) for 48 h. In both B and C, the ability of cells to survive and form colonies was determined. Number of colonies from untreated cells was set at 100 % (±SD, n = 3-4). d, Cells were treated as in B, and after 72 h of incubation the cells were harvested for Western blot analysis of cleaved (cl.) caspase 7 (marker of apoptosis) and p-H2AX (marker of DNA damage). Actin was used as the loading control