Figure 3. The cGAS/STING‐dependent cytosolic dsDNA‐sensing pathway is dispensable for interferon (IFN) signaling induced by ATR inhibition + ionizing radiation (IR).

• A
  MCF10A wild‐type (WT), cGAS knockout (KO), and STING KO cells were treated with cGAMP at indicated concentrations for 4 h, and cells were harvested for immunoblotting.
• B
  MCF10A WT, cGAS KO, and STING KO cells were transfected with herring testis DNA (HT‐DNA, 2 μg/ml) for 6 h with Lipofectamine 3000. Immunoblotting was performed with indicated antibodies.
• C–F
  (C, D, and F) MCF10A WT or two independent clones for cGAS, STING, and IRF3 KO cells were pretreated with DMSO or AZD6738 (250 nM) for 2 h, and then irradiated with 20 Gy; 3 days later, cells were harvested for immunoblotting with indicated antibodies. cGAS, STING, and IRF3 KO were verified by immunoblotting and Sanger DNA sequencing (Appendix Fig S7). (E) Same condition as described in C, except that cells were harvested for real‐time quantitative PCR. IFNB1 mRNA level was measured and statistical analyzed by two‐way ANOVA (*** means P < 0.001). Data are presented as mean ± standard error of the mean of three biological replicates.