Taken together, this study revealed that a hypoxia-responsive circRNA, circAAGAB, interacted with FUS to avoid degradation, sponged miR-378 h to up-regulate KIAA1522, NKX3-1, and JADE3, restrained cell colony formation, cell migration and invasion, and increased radiosensitivity in breast cancer cells through the p38 MAPK signaling pathway. Here, JADE3 is linked to breast carcinoma.