Fig. 4

ScaRNA2 knockdown resulted in ATR inactivation, accounting for HR defects. A-B HCT116 cells and HT29 cells with/without scaRNA2 knockdown were treated with 8 Gy irradiation, and proteins involved in the DNA damage response were detected with western blotting assays at the indicated time points. The specific sites for phosphorylated proteins are indicated. GAPDH was used as a negative control. C, D Activation of ATR and TOPBP1 in HCT116 cells was detected with immunofluorescence staining at 8 h after 8 Gy irradiation. Scale bar: 20 μm. E The numbers of ATR foci and TOPBP1 foci per nucleus in irradiated HCT116 cells with/without scaRNA2 knockdown. ****P < 0.0001, ***P < 0.001 compared with the sg-ctrl group. F sg-ctrl and scaRNA2 knockdown HCT116 cells were treated with 8 Gy irradiation, and the chromatin fractionation protein was extracted. Proteins including ATR, the MRN complex and Exo1 were detected using a western blot analysis. G The raw density of each protein in the indicated four groups was quantified and statistically analysed. ***P < 0.001, *P < 0.05 compared with the sg-ctrl group