Fig. 1

Cytotoxicity, microscopy and biochemical comparison of MDA-MB-231 and MDA-MB-231/R cells. a Proliferation of MDA-MB-231 and MDA-MB-231/R cells treated with 0.5, 10 and 20 μM of cisplatin for 48 h. Values are expressed as mean ± SEM, n = 3 experiments (triplicates). Significant differences from control (MDA-MB-231): p < 0.0001 (####); Significant differences from control (MDA-MB-231/R): p < 0.01(+ +); p < 0.0001 (+ +  + +); Significant differences from MDA-MB-231 cells: p < 0.001 (***), p < 0.0001 (****); b Representative photomicrographs of MDA-MB-231/R cells (left) and MDA-MB-231 (right). 4 independent experiments were carried out under a fluorescent objective lens (upper panel) or a phase-contrast objective lens (lower panel) of the LionheartFX microscope. Scale bar = 100 μm; c Area of polyploid giant cancer cells in MDA-MB-231 (white) and MDA-MB-231/R cells (black). Values are expressed as mean ± SEM, n = 3 experiments (triplicates). Significant differences from MDA-MB-231 cells: p < 0.0001 (****); d Phosphorylation of ERK1/2 and of NF-κB in MDA-MB-231 (white) and MDA-MB-231/R cells (black) detected using AlphaScreen Sure Fire technology. Values are expressed as mean ± SEM, n = 3 experiments (triplicates). Data are expressed as mean ± SEM, n = 3. Significant differences from MDA-MB-231 cells: p < 0.01 (**)