The expanding role of mTOR in cancer cell growth and proliferation.

The mechanistic/mammalian target of rapamycin (mTOR) is a conserved protein kinase that controls several anabolic processes required for cell growth and proliferation. As such, mTOR has been implicated in an increasing number of pathological conditions, including cancer, obesity, type 2 diabetes and neurodegeneration. As part of the mTOR complex 1 (mTORC1), mTOR regulates cell growth by promoting the biosynthesis of proteins, lipids and nucleic acids. Several mTORC1 substrates have been shown to regulate protein synthesis, including the eukaryotic initiation factor 4E (eIF4E)-binding proteins (4E-BPs) and the ribosomal S6 kinases (S6Ks) 1 and 2. In this work, we focus on the signalling pathways that lie both upstream and downstream of mTORC1, as well as their relevance to human pathologies. We further discuss pharmacological approaches that target mTOR and their applications for the treatment of cancer.