Fig. 5

CXCR4 inhibitors reverse palbociclib resistance in breast cancer cells. a Colony formation assay showing the cell viability in parental and palbociclib-resistance MCF-7 cells treated with monotherapy or combination palbociclib (1 μM) and AMD3100 (1 μM). Representative images at the left panel and quantification analysis at the right panel. b MTT assay showing the cell viability of palbociclib-resistance MCF-7 cells treated with different concentration of palbociclib with or without AMD3100 (1 μM) for 5 days. c Western blotting showing the protein level of CXCR4, WNT5A and β-catenin in palbociclib-resistance MCF-7 cells with palbociclib (1 μM) or AMD3100 (1 μM) mono- or combination treatment. GAPDH as a loading control. d Immunofluorescence assay showing the nuclear and cytoplasmic distribution of β-catenin and CXCR4 in MCF7-palR cells with mono- or combination CXCL12 and AMD3100 treatment. e Western blotting showing the protein level of CXCR4, WNT5A and β-catenin in CXCR4-overexpressed MCF-7 cells treated with AMD3100 (1 μM). GAPDH as a loading control. For a, b, n = 3 biologically independent experiments, the p values were calculated by Student’s t-test for two group comparison and one-way ANOVAs for multiple groups, ***p < 0.001, **p < 0.01. For c-e, representative images of three biologically independent experiments were shown