The expanding relevance of nuclear mTOR in carcinogenesis

Deregulated mTOR signaling drives the growth of various human cancers, making mTOR a major target for development of cancer chemotherapeutics. The role of mTOR in carcinogenesis is thought to be largely a consequence of its activity in the cytoplasm resulting in increased translation of pro-tumorigenic genes. However, emerging data locate mTOR in various subcellular compartments including Golgi, mitochondria, endoplasmic reticulum and the nucleus, implying the presence of compartment-specific mTOR substrates and functions. Efforts to identify mTOR substrates in these compartments, and the mechanisms by which mTOR recruits these substrates and affects downstream cellular processes, will add to our understanding of the diversity of roles played by mTOR in carcinogenesis.