Fig. 5

CDKN1A is required for chemoresistance in breast cancer cells. The expression of CDKN1A in MDA-MB-231 cells was knocked down with specific targeting siRNA or overexpressed with a plasmid, and then the cells were treated with Dox (1 μg/ml) for 24 h. a Cell growth was measured by colony formation assays. The data are shown as the mean ± s.e.m. of three independent experiments. The statistical significance of the differences between the experimental group and control group (Dox) was evaluated with a Student’s t-test, ***p < 0.001. b Apoptosis was measured by flow cytometry based on Annexin V/PI double staining. The data are shown as the mean ± s.e.m. of three independent experiments. The statistical significance of the differences between the experimental group and control group (Dox) was evaluated with a Student’s t-test, *p < 0.05, ***p < 0.001