Figure 6. Casp3 KO inhibits tumor formation, and radiations activate the ATM/p53/Cox-2 axis in vivo. (A) Treatment scheme for nude mice. (B) Images of tumors obtained on day 22. (C) The tumor volume of xenografts was measured with calipers every 2 or 3 days (**p<0.01, ***p<0.001, Student’s t test, n = 7). (D) Representative photomicrographs of hematoxylin and eosin (H&E) and immunohistochemical staining of caspase-3, cleaved caspase-3, ATM, pATM (S1981), Chk2, pChk2 (T68), p53, pp53 (S15), and Cox-2 in tumor tissues. Scale bars: 50 μm.