Downregualtion of RECQ1 leads to defects in cell cycle progression and DNA synthesis in glioblastoma T98G cells. A) Flow cytometry profiles of DNA content (x-axis; propidium iodide/PI staining) versus BrdU incorporation (y-axis; anti-BrdU immunostaining) 72 h after siRNA transfection. Boxes are labeled to indicate cell cycle phases. B) The bar graph at bottom reports the percentage of G0/G1, S-phase/BrdU positive and G2/M cells in cultures that had been transfected with RECQ1 or luciferase/control siRNA pools. Results shown are the mean ± SEM from three independent experiments. C) The graph shows the cellular surviving fractions measured at different doses of hydroxyurea in control and RECQ1-depleted T98G cells. Surviving fraction values are the mean ± SEM from three independent experiments.