Fig. 1.

Palbociclib inhibits cell proliferation through G0/G1 cell cycle arrest. a The expression of cell cycle-related proteins was analyzed by Western blotting in TNBC and ERα + cells 24 h after seeding. b TNBC and ERα + cell lines were treated with increasing concentrations of palbociclib (0.01-10 μM); after 72 h cell proliferation was evaluated by CV staining. The EC₅₀ values are shown. c TNBC cells were treated in absence (ctrl) or presence of 0.5 μM palbociclib. After 24 h the distribution of cells in cell cycle phases was determined by flow cytometry. d MDA-MB-231(i) and HCC38 (ii) cells were treated with palbociclib 0.5 μM and 1 μM, respectively. After 24 h palbociclib was removed and cell cycle phase distributions were evaluated by flow cytometry at the indicated time points. ***p < 0.001 vs corresponding G0/G1 ctrl. Results in a are representative of three independent experiments. Data in b-d are means ±SD of three independent experiments (n = 5)