Fig. 4

Validation of candidate genes by targeted inhibition and clonogenic survival assays. A Clonogenic survival of A172 and U251-MG cells after single-shot IR (0–10 Gy) and ATR inhibition by AZD-6738 (0–1.0 μM, upper panel). Immunofluorescence staining of γH2AX and 53BP1 20 h after irradiation at 4 Gy ± ATR inhibition by 1 µM AZD-6738 (lower panel). γH2AX is depicted in green, 53BP1 in red, and DNA is depicted in blue. Scale bar represents 10 µm. B Clonogenic survival of A172 and U251-MG cells after single-shot IR and LIG4 inhibition by L189 (0–50 μM, upper panel). Immunofluorescence staining of γH2AX and 53BP1 20 h after irradiation at 4 Gy ± LIG4 inhibition by 50 µM L189 as performed in A (lower panel). C Clonogenic survival of A172, U138-MG, and U251-MG cells after 24 h treatment with TMZ (0–200 μM) and ATM inhibition by KU-60019 (0–1.0 μM). Super-imposed fitting functions are linear-quadratic in case of radiation experiments and logistic in case of TMZ treatment. Results of three independent experiments are depicted for each condition, and p-values were calculated by two-way ANOVAs