A549 human lung adenocarcinoma

A549 human lung adenocarcinoma and L929 mouse fibroblast cell lines were obtained from American Type Culture Collection (ATCC) (Manassas, VA, USA). Both cell lines were cultured, and drug treatments were carried out as previously reported [31 (link),86 (link)].

A549 human lung adenocarcinoma and HBE135-E6E7 human lung epithelial cells were purchased from the American Type Culture Collection (Manassas, VA, USA). A549 cells were maintained in high-glucose Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal bovine serum and 1% antibiotics (penicillin-streptomycin) (Invitrogen, Thermo Fisher Scientific, Waltham, MA, USA). HBE cells were maintained in keratinocyte serum-free medium supplemented with 5 ng/ml human recombinant epidermal growth factor, 0.05 mg/ml bovine pituitary extract, 0.005 mg/ml insulin, 500 ng/ml hydrocortisone, and 1% antibiotics (all from Invitrogen). Cells were cultured at 37°C in a humidified incubator with a constant airflow of 5% CO₂. For ATM and AKT inhibition, cells were treated with caffeine (5 mM) (Sigma, Shanghai, China) solubilized in distilled water and LY294002 (40 μM) (Merck KGaA, Darmstadt, Germany) solubilized in dimethylsulfoxide for 2 h prior to irradiation. Media containing the inhibitors were replaced with fresh medium immediately after irradiation.

The A549 human lung adenocarcinoma and H1299 human lung carcinoma cell lines were obtained from the American Type Culture Collection. Cells were maintained in Dulbecco’s modified Eagle’s medium (DMEM) basic medium supplemented with 10% fetal bovine serum and 1% antibiotics at 37 °C with 5% CO₂.