Fig. 6

The synergistic effects for SCR-6852 combined with CDK4/CDK6 inhibitor in vitro and in vivo a MCF7 were treated with increasing concentrations of SCR-6852 and/or Palbociclib for 7 days in a 384-well plate. Cell viability was measured using Cell TiterGlo assay. Combination analysis with Loewe’s additivity mode by SynergyFinder (https://synergyfinder.fimm.fi) displayed surfaces of synergy on the left; red indicates synergy (synergy score > 0) and green indicates antagonism (synergy score < 0). The potency shift of Palbociclib combined with a serial SCR-6852 dosing were represented graphically as dose–response curves, on the right. b MCF-7 cells were treated with SCR-6852 or combined Palbociclib for 40 h, and cell cycle distribution was analyzed by Flow cytometry. The result of one representative assay from three similar independent experiments is shown. The percentages of cells in G1, S, and G2/M were shown as indicated. c The MCF-7 tumor-bearing Balb/c nude mice received the vehicle, 250 mg/kg Fulvestrant, 40 mg/kg Palbociclib, 0.3 mg/kg SCR-6852, 1 mg/kg SCR-6852, or combination treatments as indicated in the graph (n = 8/group). The error bars represent the standard error of the mean (SEM). ****P < 0.0001; **P < 0.01 combination versus single as indicated