Fig. 4
Cariporide activates the doxorubicin-induced apoptosis pathway. (a) Cells were either untreated or pretreated with 6 μg/ml cariporide (CP) and 10 μg/ml doxorubicin (ADR) alone for 48 h. The combination group contained cariporide (6 μg/ml) for 24 h followed by addition of doxorubicin (10 μg/ml) for another 24 h. The whole cell lysates were immunoblotted for MDR1, CD44, NF-κB p65 and (c) p-AKT, cleaved caspase 3/9, and Bcl-2. (b) MCF-7/ADR cells were treated with 6 μg/ml cariporide and/or 10 μg/ml doxorubicin for 24 h. The cell isolations were prepared for MDR1 mRNA and (d) NF-κB mRNA subjected to RT-PCR analysis. (e) Female nude mice were randomized and inoculated with MCF-7/ADR cells (5 × 106/ml), and the growth of implanted breast tumors was monitored every week after inoculation until the volume increased to 1 cm3. Xenograft tumors were treated with either cariporide (3 mg/kg) or doxorubicin (5 mg/kg), or their combination every two days for a total of seven times. On day 21 posttreatment, all animals (n = 20) were sacrificed, and the tumors were removed and measured. The data represent the means ± SD from at least 3 animals per group. (f) Body weight and tumor size were measured twice a day using calipers, and (g) tumor volumes were plotted