The mammalian target of rapamycin (mTOR) plays a critical role in the regulation of cell growth, proliferation,
and metabolism by integrating growth factor stimulation and energy/nutrient input through a complex signaling network.
The mTOR kinase is a part of two structurally and functionally distinct multiple protein complexes, mTORC1 and
mTORC2. The mammalian target of rapamycin complex 1 (mTORC1) is rapamycin-sensitive and mediates temporal
control of cell growth by regulating several cellular processes, such as translation, transcription, and nutrient transport
while the mammalian target of rapamycin complex 2 (mTORC2) is insensitive to rapamycin and is involved in spatial
control of cell growth via cytoskeleton regulation. Here we discuss the mechanism of mTOR regulation in tumor
malignancy through a variety of signaling pathways and the potential of mTOR inhibitors for the treatment of cancer.