Figure 3.

Human U1242/luc-GFP gliomas show dose-dependent increases in γ-H2AX, p-(S824)-KAP1, and 53BP1 foci formation after radiation. Athymic female mice growing U1242/luc-GFP intra-cranial tumors were exposed to 0, 5 or 10 Gy followed by perfusion with fixative immediately, 1, or 2 hr post-irradiation. Brains were post-fixed, embedded in OCT and sectioned on a cryostat in 6-μm sections. Sections were stained with anti-p-(S139)-H2AX (A and B), p-(S824)-KAP1 (C), and 53BP1 (D) antibodies, respectively, followed by goat anti-mouse-Alexa 594. Nuclei were counterstained with DAPI. Section (A) shows GFP+ U1242/luc-GFP tumor whereas (B – D) do not. Instead, the characteristic elongated shape of the U1242 cells is clearly seen after DAPI staining.