Fig. 4

PICT1 deletion impairs DNA damage repair in A549 cells. Panel I: CRISPR-Cas9 strategy was used to generate cells with PICT1 deletion as described in the Methods section. A Representative Western blotting image of wild-type A549 cells and cells with PICT1 deletion. B Cells were treated with 20% cigarette smoke extract (CSE) for 24 h. Histograms were obtained by flow cytometry analysis using a DCF-DA probe. C DCF fluorescence intensity was quantified. D Representative images of comets (scale bar—5 µm). E Olive tail moments were quantified. Panel II: Wild-type A549 cells and cells with PICT1 deletion were treated with 20% CSE for 24 h. A Representative Western blotting images of MRE11, 53BP1, LIGASE IV, and KU80 expression. B-E Quantification of protein levels is shown. Panel III: mRNA expression of MRE11 (A), 53BP1 (B), KU80 (C), and LIGASE IV (D) by RT-PCR. Data are shown as means ± SEM (C – control; N = 3 – 9 experimental replicates). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001