Figure 5.
The MDM2/MDMX inhibitor can reverse DOX resistance of breast cancer in nude mice. Each mouse group was injected into the mammary fat pad with MCF-7/DOX cells (5×106 cells). The cells were re-suspended in PBS and mixed with matrigel. When the tumors reached the approximate size of 200 mm3, tumor-bearing mice were randomly divided into four groups (six in each group) and treated with the following regimens: Normal saline; DOX (2.5 mg/kg, iv, twice per week); MDM2/MDMX inhibitor (10 mg/kg, iv, d1-3); and the combination of MDM2/MDMX inhibitor and DOX. The body weights of mice and the tumor volumes were recorded. The tumor volume and tumor weight quantified data (A, B) is shown. Representative hematoxylin-eosin staining (H&E) and immunohistochemical P-gp and MRP staining of breast cancer xenografts (C), and expression intensity calculated as IOD/Area (D) are also presented. Bars: 50 μm. The values presented are indicative of the mean ± SD for each group. *P<0.05, **P<0.01, ***P<0.001 (n = 6) vs. the control group, the DOX group or the MDM2/MDMX inhibitor group.