Figure 5. Co-knockdown of NOX4 or DUOX2 with p53 or p21 restores cell cycle entry.

a) DNA content scatter plots in which the color of the points represents the density of the points in a given region. The density is calculated by the reciprocal of the area of the voronoi region surrounding the centroid of a point. The two siRNA that were transfected are listed at the top of each plot. For all of the co-knockdown experiments the total siRNA concentration was kept constant by adding negative control siRNA to ensure that any effects we observed were not due to concentration differences. b) Results of the cell cycle entry assay for co-knockdown of synthetic pools of NOX4, DUOX2 or non-targeting siRNA (all Dharmacon siGENOME siRNA) with p21 or non-targeting negative control siRNA. The light grey bars were normalized to the fraction of Rb-positive cells in samples transfected with (−)CTRL/(−)CTRL siRNA. The dark grey bars were normalized to the fraction of Rb-positive cells for cells transfected with (−)CTRL/p21 siRNA. P-values were calculated using a t-test assuming a normal distribution. c) Results of the cell cycle entry assay for co-knockdown of synthetic pools of NOX4, DUOX2 or non-targeting siRNA (all Dharmacon siGENOME siRNA) with p53 or non-targeting negative control siRNA. The light grey bars were normalized to the fraction of Rb-positive cells in samples transfected with (−)CTRL/(−)CTRL siRNA. The dark grey bars were normalized to the fraction of Rb-positive cells for cells transfected with (−)CTRL/p53 siRNA.