Fig. 3: ER inhibition ± AR inhibition with enzalutamide is not sufficient to radiosensitise AR+/ER+ breast cancer cells in vitro.

Clonogenic survival assays were performed in a CAMA-1 or b ZR-75-1 cells with a 1 h pretreatment of tamoxifen prior to radiation treatment. Radiosensitisation was assessed by clonogenic survival assays in c CAMA-1, d BT-474 and e ZR-75-1 cells with treatment of fulvestrant, a known degrader of both ER and AR protein. f Clonogenic survival assays were also performed in ACC-422 cells (AR+/ER−) with fulvestrant. Additional clonogenic survival assays were performed in g CAMA-1, h ZR-75-1 or i BT-474 cells with a 1 h pretreatment of enzalutamide, tamoxifen, or enzalutamide and tamoxifen. Representative clonogenic survival assays are shown for each cell line, and the SF-2Gy are representative of three independent experiments (mean ± SEM). *p < 0.05; **p < 0.01; ***p < 0.001; NS not significant.