Fig. 2

Upregulation of GSDME enhances pyroptosis and radiosensitivity in NPC cells in vitro. A The ratio of pyroptotic cells to dead cells in six NPC cell lines (HNE1, 5-8F, 6-10B, SUNE-1, HONE1, and HK1) within 72 h after 6 Gy irradiation, as calculated using live cell imaging data (left). Correlation analysis between the ratio of pyroptotic cells to dead cells and surviving fraction was performed (right). B Correlation analysis between relative GSDME-N levels and the surviving fraction in NPC cell lines within 72 h after 6 Gy irradiation was performed. C Western blotting showed GSDME expression in seven NPC cells and eight other cancer cells. MM: melanoma, EC: esophageal cancer, PCa: prostate cancer, BC: breast cancer. A375 cells were included as a positive control. D-M Stable GSDME-overexpressing SUNE1 cells (D, left upper) and stable GSDME-knockdown HK1 cells (E, left upper) were established. These cells were exposed to the indicated irradiation dose, and then phase-contrast cell imaging (D, E, right), LDH release assay (D, E, left lower), Western blotting analysis of GSDME-N (F, H), live cell imaging (G, I), Annexin/PI assay (J, K), and colony formation assay (L, M, left) were performed at designated time points. The survival curves of stable cell lines are indicated (L, M, right). GAPDH was used to determine the amount of loading proteins. All data are presented as the mean ± SD of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001