Figure 8

(a) Representative figures of autophagic cells induced by a single dose of 10-Gy X-rays in siRNA-Luc SAS and psiRNA-hBeclin-1 SAS cells. Autophagosomes were immunocytochemically visualized by anti-LC-3 antibody. (a-1) siRNA-Luc SAS cells without irradiation. (a-2) siRNA-Luc SAS cells 5 days after exposure to 10 Gy. In almost all cells the number of autophagosomes were increased. Some cells entered into hyperinduced autophagic cells (arrows). (a-3) siRNA-Luc SAS cells 5 days after exposure to 10 Gy of X-rays. High magnification. (a-4) psiRNA-hBeclin-1 SAS cells without irradiation. These cells express GFP as a marker for transfection. Therefore faint fluorescence was observed in nuclei. (a-5) psiRNA-hBeclin-1 SAS cells 5 days after exposure to 10 Gy of X-rays. Although autophagosomes were observed in cytoplasm, the number was apparently lower than that of siRNA-Luc SAS cells, indicating that induction of autophagy is suppressed by Beclin-1 knockdown. (a-6) psiRNA-hBeclin-1 SAS cells 5 days after exposure to 10 Gy of X-rays. High magnification. (b) Hyperinduced autophagic cells 5 days after exposure to 10 Gy of X-rays in siRNA-Luc SAS and psiRNA-hBeclin-1 SAS cells. (c) Radiation sensitivity of siRNA-Luc SAS and psiRNA-hBeclin-1 SAS. (d) Cell growth of siRNA-Luc SAS and psiRNA-hBeclin-1 SAS without radiation or 5 × 2 Gy of X-rays. Mean±S.D. of three independent experiments. ^*P<0.05