Fig. 4. Higher MDM4 expression in hESC^1q results in a decreased sensitivity to DNA damage-induced apoptosis.

A Percentages of apoptotic and live cells in hESC^wt, hESC^1q and treated hESC^1q with siMDM4 and Nutlin-3a upon 0 h, 2 h, 4 h and 6 h of exposure to Bleomycin. B Evolution of the numbers of cells from day 0 to day 8, for hESC^1q, hESC^wt and a 1:9 mix of hESC^1q and hESC^wt. C Percentage of hESC^1q over the course of 8 days in culture, starting from a 1:9 mix of hESC^1q and hESC^wt. The proportion of hESC^1q becomes significantly increased as from day 4. *p < 0.05. D Representative images illustrating the cell density at days 3 and 4 of the time-course experiment. Confluency is reached on day 4 of this experiment. 1q cells are shown in red and DNA in blue. E Examples of the staining for gammaH2AX (green) in hESC^1q and hESC^wt, upon exposure to Bleomycin and in low- and high-density cultures. DNA is shown in blue. F Cell densities for the low- and high-density culture conditions shown in (E and G). The dots represent the counts made in different images of dishes of different cell lines. The line represents the mean of the dots. G Counts of gammaH2AX foci per nucleus in hESC^1q and hESC^wt at low and high-density culture conditions. Each dot represents a single nucleus, hESC^wt-low N = 976, hESC^wt-high N = 2879, hESC^1q-low N = 2995, hESC^1q-high N = 7158. H Cell densities of hESC^wt, hESC^1q and mixes calculated from cell counts during a 5-day culture period.****p < 0.0001, one-way ANOVA and Šidák correction. ns = non-significant.