Figure 4.

Inhibition of DNA replication by exosomes from irradiated cells. (A) Foci of newly replicated DNA initiated in FaDu cells after one-hour of incubation with exosomes released by sham-irradiated (Ex_0Gy) or irradiated (Ex_2Gy) cells or with HU or CPT. (B) Visualization of RNA:DNA hybrids in nuclei of FaDu cells incubated for 3 h with Ex_0Gy or Ex_2Gy vesicles; the graph shows the relative occupancy of RNA:DNA hybrids in the nuclei cells incubated with exosomes (1 or 3 h) or HU (1 h). Box plots show the median, minimum, maximum, and lower and upper quartiles; statistically significant differences between groups are represented by asterisks: * p < 0.05 and ** p < 0.001 (only differences between Ctr and exosome-stimulated cells are shown for clarity).