Effect of FGFR1 overexpression on palbociclib-induced inhibition of cell cycle progression and cell cycle regulators. (A) MCF-7/C and MCF-7/FGFR1 cells were treated with palbociclib (0, 2.5, 5, 10 μM) for 24 h, followed by cell cycle analysis. Cells in different phases were analyzed with ModFit software. (** p < 0.01, * p < 0.05 vs. corresponding phases of control cells). Data from triplicate samples were reported. (B1) Western blot detection of key cell cycle regulators regulated by palbociclib. MCF-7/C and MCF-7/FGFR1 cells were treated with palbociclib, at the indicated concentrations, for 48 h, followed by Western blot analysis of specified markers. (B2) Protein levels of key markers in (B1) in MCF-7/C and MCF-7/FGFR1 cells in the absence of palbociclib.