Fig. 2

Combination therapy with MPSE enhances IR-induced cell death in breast cancer cells. A Apoptosis was assessed by flow cytometry with FITC-conjugated annexin V/PI staining. MCF7 and MDA-MB231 cells were pre-treated with MPSE (20 μg/mL) for 24 h, and then irradiated with 6 Gy of IR. After 24 h of incubation, MCF7 and MDA-MB231 cells were co-stained with annexin V-FITC and PI and were subjected to flow cytometer. B Quantification of apoptotic cell percentage showed that MPSE enhanced IR-induced apoptosis. The data are presented as mean ± SD of three independent experiments (numbers in the bars represent the mean of each group). The statistical significance of each group was analyzed by a one-way ANOVA and Tukey’s HSD test (* p < 0.05). C Representative image of senescent cells (blue-stained cells) taken from inverted microscope at a 200× magnification. D The percentage of senescent cell population of breast cancer cell lines after sixth day of irradiation. Bar graph shows a mean ± SD (numbers in the bars represent the mean of each group). The statistical significance of each group was analyzed by a one-way ANOVA and Tukey’s HSD test (* p < 0.05)