Figure 2: Concurrent pharmacological inhibition of CDK4/6 in ER+ breast cancer cell lines confers radiosensitivity.
Clonogenic survival assays were performed in MCF-7 (A) and T47D (B) cells with 1-hour pretreatment of the CDK4/6 inhibitor palbociclib at 1–100nM palbociclib. Clonogenics were also performed with ribociclib (C,D) and abemaciclib (E,F) and the surviving fraction of cells was calculated for each treatment condition at 2 Gy. Radiation enhancement ratios (rER) are shown. (p < 0.05 = *, p < 0.01 = **, p < 0.001 = ***).