Effects on apoptosis in Tz-sensitive (A, B) and -resistant (C, D) breast cancer cell lines.

Cells were treated with Se, Tz, or combinations of both drugs for 72 h. Cell deaths after treatments were analyzed by flow cytometry. Blue dots shows cell survival in the left lower quadrant, early apoptosis in right lower quadrant, late apoptosis in right upper quadrant and necrosis in left upper quadrant. Bars represent percentage of cells in each area analyzed by using flow cytometry. One-way ANOVA followed by post Scheffe test was used for statistical analysis to compare between groups. (*P < 0.05; **P < 0.01 significantly different from control; ^# P < 0.05; ^## P < 0.01 significantly different from Tz single treatment).