FIGURE 3.

Pol III is essential for the presence of cytosolic RNA:DNA hybrids. A, A549 cells were treated with the indicated concentration of the Pol III inhibitor (RP III inh.) ML-60218 for 3 h before staining with 10 μl/ml PicoGreen (green) for 1 h and with 100 nm MitoTracker (red) for 30 min. Scale bars = 10 μm. B, cytosolic and nuclear intensity quantification of the images shown in A. A two-tailed Wilcoxon test was performed. Error bars represent S.E. *, p < 0.05. C, A549 cells were treated with the indicated concentrations of the Pol III inhibitor ML-60218 for 3 h before staining with RNA:DNA hybrid-specific S9.6 antibody (green) and Hoechst (blue). D, cytosolic and nuclear intensity quantification of the images shown in C. A two-tailed Wilcoxon test was performed.