Fig. 6

Sensitivity of GAC cell lines to radiation treatment. A Consensus subtypes in GAC cell lines (n = 37 in CCLE data set). GAC cell lines were stratified according to nearest shrunken centroids probability from the GPICS120 predictor. B Log-linear plot demonstrating the relative sensitivity of the 5 GAC cell lines (AGS, NUGC3, SNU668, MKN1, and Hs746T) to ionizing radiation over the range of 0 to 8 Gy as determined by a colony-counting assay. Each point represents the mean of 5 replicates. **P < 0.001 for AGS or NUGC3 vs. other cells. C-I Inhibition of ferroptosis induces resistance to ionizing radiation and abrogates statin-mediated radiosensitization. Colony-counting assays showed that ferrostatin-1 (fer-1), an inhibitor of ferroptosis, abrogates statin-mediated radiosensitization in radiation-resistant SNU668 and Hs746T gastric cancer cells (C-F). Furthermore, fer-1 makes radiation-sensitive AGS and NUGS3 gastric cancer cells resistant to ionizing radiation (G, I). Seeded cells were exposed to ionizing radiation over the range of 0 to 8 Gy as indicated. P-values indicate the significance of the differences at the 8-Gy dose in each experiment. Means (± SEM) of at least 3 experiments are shown. Atorva, atorvastatin; Simva, simvastatin. *P < 0.01, **P < 0.001