Figure 2.

The cGAS-STING pathway of TNBC cells was activated by serum depletion which was suppressed by treatment with RU.521. MDA-MB-231 cells (A) and SUM159 cells (B) were grown in normal or serum-depleted media in the presence or absence of RU.521 (10 μM) for 24 hr. Total TBK1 and pSer172 TBK1 were detected by immunofluorescence staining with the corresponding antibodies. Fluorescent images were captured at 630x magnification. The nuclei were counterstained by DAPI. Bar, 25 μm. The images were quantitated and plotted with three independent results are shown as means ± SD, and the statistical significance was calculated by Student’s t-test. **, p < 0.01, ***, p < 0.001. NS, non-significant with the p values greater than 0.05.