Fig. 4

Combinatorial treatment with CSC-3436 and tamoxifen induced stronger G2/M phase arrest and anti-proliferative ability. a Chemical structure of CSC-3436. b MDA-MB-231 cells were treated with several concentrations (0, 25, 50, 100, 200 and 400 nM) CSC-3436 for 48 and 72 h. Cell proliferation was assessed using the MTT assay. The percentage of cell growth inhibition was calculated by the absorption of control cells as 100 %. c MDA-MB-231 cells were treated with various concentrations (0, 2.5, 5, 7.5, 10 and 15 μM) tamoxifen alone or in the presence of CSC-3436 (100, 200, and 400 nM) for 48 h. Cell proliferation was assessed using the MTT assay. The percentage of cell growth inhibition was calculated by the absorption of control cells as 100 %. d MDA-MB-231 cells were treated with CSC-3436 (200 nM) and tamoxifen (2.5 μM) alone or CSC-3436 (200 nM) plus tamoxifen (2.5 μM) for 48 h. Sub-G1 and G2/M phase were assay by PI staining. *p < 0.05 compared with control group. e MDA-MB-231 cells were treated with CSC-3436 (200 nM) and tamoxifen (2.5 μM) alone or CSC-3436 (200 nM) plus tamoxifen (2.5 μM) for 48 h followed by analysis of PARP and Caspase-3 by western blotting