ATM-mediated DNA double-strand break response facilitated oncolytic Newcastle disease virus replication and promoted syncytium formation in tumor cells
Fig 5
NDV late infection and membrane fusion activated the ATM-Chk2 axis in A549 cells.
(A) Representative images showing that virulent oncolytic NDV infection triggered nuclear aggregation of phosphorylated Chk2 on Thr48 in A549 cells. A549 cells were mock-infected and NDV-infected (MOI = 1) for 12, 18, 24, and 30 h, and UV exposed for 30 and 60 min. After treatment, the A549 cells were collected, fixed, and visualized by IFA. The UV-exposure group served as the positive control. Phosphorylated Chk2 (green); nuclei (blue); NDV (red). Scale bars = 20 μm. (B) Statistical analysis of the nuclear aggregation punctate foci numbers of phosphorylated Chk2 on Thr 48 in response to virulent oncolytic NDV infection in A549 cells. Numerical data were the average number of punctate foci in different microscope fields in at least three independent experiments. Significance was analyzed using two-tailed Student’s t-test. The UV-exposure group served as the positive control. NS, p > 0.05; *, p < 0.05; **, p < 0.01; ***, p < 0.001. (C) Representative images showing that F-HN co-expression triggered nuclear aggregation of phosphorylated Chk2 on Thr 48 in A549 cells. A549 cells were mock transfected or co-transfected with both Flag-F and HA-HN plasmids at the indicated time. At 24 and 30 h.p.t., coverslips were examined by IFA. Phosphorylated Chk2 (green); nuclei (blue); NDV (red). Scale bars = 20 μm. (D) Statistical analysis of the nuclear aggregation punctate foci number of phosphorylated Chk2 on Thr 48 in response to F-HN co-expression.