MTOR and cancer: The effects of metformin on cancer cell proliferation were associated with AMPK activation, reduced mammalian target of rapamycin (mTOR) signaling and protein synthesis, as well as a variety of other responses including decreased epidermal growth factor receptor (EGFR), Src, and mitogen-activated protein kinase (MAPK) activation, decreased expression of cyclins, and increased expression of p27.