Fig. 4. Overexpression of GADD45α enhances sensitivity of radioresistant cervical cancer cells to radiation treatment.

a GADD45α was significantly increased by transfection of GADD45α expression plasmid in HeLa-XR cells. Western blot analysis was performed 72 h after transfection. b, c Clonogenic and CCK-8 assays showed that overexpression of GADD45α significantly induced radiation-induced cell death compared to vector controls in HeLa-XR cells. d Comet assay showed that overexpression of GADD45α significantly stimulated radiation-induced DNA damage compared to vector controls in HeLa-XR cells. e Apoptosis analysis showed that overexpression of GADD45α significantly stimulated radiation-induced apoptosis compared to vector controls in HeLa-XR cells. f Cell cycle analysis showed that overexpression of GADD45α significantly stimulated radiation-induced G₂/M cell cycle arrest compared to vector controls in HeLa-XR cells. Each experiment was repeated three times. The significance between indicated groups was determined using a t test. **p < 0.01; ***p < 0.001