Figure 2.

231Br breast cancer cells are more sensitive to AZA treatment compared to 231 cells. (A) IC₅₀ values of AZA in both cell lines were calculated using the MTT assay. The IC₅₀ value of AZA is 48 ± 4.90 μM in 231Br cells and 83.33 ± 8.82 μM in 231 cells (P < .01). (B) 231 and 231Br cells were treated with various concentrations of AZA for 72 hours, and the Annexin V–positive cells were considered as apoptotic cells. Treatment with 20 μM and 100 μM of AZA triggers higher percentage of apoptotic cells in 231Br cells compared to 231 cells. IC₅₀ values and percentage of Annexin V–positive cells were compared between the two cell lines using Student's t test. All error bars represent SD, N = 3 technical replicates, representative of three independent experiments. *P < .05, **P < .01, ***P < .001. (C) Expression of BCL-2 and BCL-xL in 231 and 231Br cells after AZA treatment for 72 hours measured by Western blotting assay. Beta-actin was used as the loading control. The blots shown are a presentation of two independent experiments. (D) Expression of caspase-3 and caspase-9 in 231 and 231Br cells after AZA treatment for 72 hours. Beta-actin was used as the loading control. The blots shown are a presentation of two independent experiments.