Fig. 6

Cell cycle distribution. 24 h and 72 h after treatment with single drugs (5-aza-dC, RES, ABC; concentrations see Table 1) or irradiation with 2 Gy, cells were fixed and stained with propidium iodide (PI). The fluorescence intensity of the PI-positive DNA correlates with the cell cycle phase distribution and was measured by flow cytometry. a Histograms of the cell cycle distribution in untreated control cells. The different cell cycle phases corresponding to the PI fluorescence intensity are indicated. b Relative fraction of cells distributed in sub-G1, G0/G1, S, or G2/M cell cycle phase, grey bars: 24 h, black bars: 72 h after drug administration or IR. Values are normalized to control (=0) and presented as mean ± SEM, n = 3. Statistical significances are presented vs. control by asterisks (*, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.001). The joint analysis included the relative data of the three MB cell lines