Abstract
Akt and mTOR are therapeutic targets for the treatment of cancer. The effects of inhibiting mTOR, with rapamycin, and Akt, with A-443654, concurrently, on cell morphology, cell proliferation, the cell cycle, and apoptosis were examined using the benign MCF10A and malignant MCF10CA1a human breast epithelial cells. Rapamycin and A-443654 in combination produced the greatest morphological changes and inhibited cell proliferation by G2/M arrest. Rapamycin and A-443654 in combination induced apoptosis at earlier times and at lower A-443654 concentrations in MCF10CA1a tumor cells than in the benign MCF10A cells. Rapamycin and A-443654 increased p53 and p15(INK4B) protein levels, decreased anti-apoptotic Bcl-2 levels, and increased Bad levels in the MCF10CA1a tumor cells by approximately 5-fold. These results suggest that the combined inhibition of Akt and mTOR may have beneficial therapeutic and safety margin effects.