Rapamycin Inhibits IGF-1-Mediated Up-Regulation of MDM2 and Sensitizes Cancer Cells to Chemotherapy
Figure 6
Rapamycin treatment reduces MDM2 expression and sensitizes cancer cells to doxorubicin-induced apoptosis.
(A–B) MCF-7 cells were maintained in normal growth media, pretreated with rapamycin (100 nM) for 48 hours, and then treated with doxorubicin (0.6 µg/mL) for 24 hours. Both floating and adherent cells were collected, and subjected to trypan blue exclusion assay (A) and western blot analysis (B). Cell viability is presented as a percentage of live cells over total cells counted. Data presented as means and SE of three independent experiments performed in triplicate. (C) SJSA-1 cells were maintained in normal growth media, pretreated with rapamycin (100 nM) for 48 hours and then treated with doxorubicin (1 µg/mL) for 36 hours. Both floating and adherent cells were collected, and subjected to western blot analysis. (D) Morphology of SJSA-1 cells was recorded by phase contrast microscopy (100×).