Research Paper Volume 12, Issue 21 pp 21758—21776

Caspase-3 knockout attenuates radiation-induced tumor repopulation via impairing the ATM/p53/Cox-2/PGE2 pathway in non-small cell lung cancer

Figure 4. Casp3 KO attenuates the DDR via ATM/p53 signaling in irradiated NSCLC cells. (A) Immunofluorescence analysis of 8 Gy-irradiated wild-type and Casp3 KO NSCLC cells co-stained for EndoG and γH2AX foci at 48 h. Scale bars: 25 μm. (B) Western blot analysis of EndoG in the cytoplasmic and nuclear fractions of 8 Gy-irradiated wild-type and Casp3 KO NSCLC cells at 48 h. β-tubulin and Histone H3 were used as cytoplasmic and nuclear loading controls, respectively. (C) Levels of DNA damage response (DDR)-related proteins ATM, pATM (S1981), Chk2, pChk2 (T68), p53, and pp53 (S15) were measured by western blotting at indicated times after 8 Gy irradiation of wild-type and Casp3 KO NSCLC cells. GAPDH was used as the loading control.