Fig. 1. Inhibition of cell proliferation by carbon ion irradiation: (a) A549 clone formation; (b) cell proliferation rate

Fig. 2. Morphological changes of mitochondria after different dose of carbon ion radiation: (a, b) Mito-tracker Green/Red staining of mitochondria in A549; (c) mitochondrial length of single cell; (d) dye enrichment in single cell (color online)

Fig. 3. Level of mitochondrial dependent apoptosis increased with carbon ion radiation: (a~f) Western blot of Bax / Bak, and their relative expression of protein and mRNA; (g~j) Western blot of Cyto-C / SMAC protein, and their relative expression of protein; (k~n) Immunofluorescence staining of Cyto-C and SMAC, and their average fluorescence intensity; (o) Annexin-V/PI staining, flow cytometry to detect apoptosis; (p) Apoptotic rate of A549 cells at different doses

Fig. 4. Level of mitophagy increased after carbon ion irradiation: (a) immunofluorescence co-localization of lysosome and mitochondria at different irradiation doses; (b) relative intensity of immunofluorescence co-localization of lysosome and mitochondria; (c) western blot of autophagy markers LC3B, Beclin1 and p62; (d) relative expression of LC3B II/LC3B I protein; (e~f) relative expression of Beclin1 and p62 protein; (g~i) western blot of mitophagy markers Parkin and BNIP3 and their relative expression of protein (color online)

Fig. 5. Mitochondria-free cells compared with control group: (a) western blot of Tomm20 protein in A549 cells treated with high level of CCCP and control group; (b) relative expression of Tomm20 protein; (c) Annexin-V/PI staining, flow cytometry to detect apoptosis