Figure 6.

Combination with AZD4547 synergistically enhances palbociclib-induced inhibition of cell invasion and CSC stemness. (A) Transwell invasion assays. MCF-7/FGFR1 cells were treated with palbociclib (5 μM) and AZD4547 (5 μM) alone or in combination for 30 h in invasion chambers. The invaded cells were stained, counted, and analyzed. (B) 3D culture of MCF-7/FGFR1 cells with different treatments. The cells were treated with palbociclib (5 μM) and AZD4547 (5 μM) alone or in combination in matrigel 3D culture for 7 days, followed by colony imaging and counting. The numbers of colonies in triplicate were analyzed. (C) Effect of drug combination on tumorsphere formation. MCF-7/FGFR1 cells were plated in ultra-low attachment plates and treated with 5 μM AZD4547 and 5 μM palbociclib, alone or in combination, in triplicate. Primary tumorspheres were counted and imaged after 7 days. Then single cell suspensions harvested form primary spheres were replated for secondary sphere formation for another 7 days. The spheres at each harvest were imaged and counted. Values in each set of experiments were analyzed with Student’s t-test (** p < 0.01 vs. single drug treatment).