Figure 3

Interactive effects of Smac/DIABLO peptide with chemotherapeutic drugs or TRAIL on apoptosis and colony formation. (A), MDA-MB-453 cells were pretreated with either Smac control peptide (25 μM) or Smac N-7 peptide (25 μM) for 12 h, and treated with paclitaxel (100 nM), doxorubicin (100 nM), etoposide (100 nM), tamoxifen (100 nm), irradiation (5 Gy) or TRAIL (75 nM) for 36 h. Apoptosis was measured by DAPI staining. Data represent mean ± SE. *, #, & = significantly different from the respective control at P < 0.05. (B), MDA-MB-468 cells were pretreated with either Smac control peptide (25 μM) or Smac N-7 peptide (25 μM) for 12 h, and treated with paclitaxel (100 nM), doxorubicin (100 nM), etoposide (100 nM), tamoxifen (100 nm), irradiation (5 Gy) or TRAIL (75 nM) for 36 h. Data represent mean ± SE. *, #, & = significantly different from the respective control at P < 0.05. (C), MDA-MB-453 cells were pretreated with either Smac control peptide (25 μM) or Smac N-7 peptide (25 μM) for 12 h, and treated with tamoxifen (100 nm), doxorubicin (100 nM), paclitaxel (100 nM) or TRAIL (75 nM) for 21 days. No. of colonies were determined by soft agar assay. Data represent mean ± SE. *, #, & = significantly different from the respective control at P < 0.05. (D), MDA-MB-468 cells were pretreated with either Smac control peptide (25 μM) or Smac N-7 peptide (25 μM) for 12 h, and treated with tamoxifen (100 nm), doxorubicin (100 nM), paclitaxel (100 nM) or TRAIL (75 nM) for 21 days. No. of colonies were determined by soft agar assay. Data represent mean ± SE. *, #, & = significantly different from the respective control at P < 0.05. represent mean ± SE.