Mammalian target of rapamycin: master regulator of cell growth in the nervous system

Histol Histopathol. 2007 Aug;22(8):895-903. doi: 10.14670/HH-22.895.


The mammalian target of rapamycin (mTOR) is a highly conserved serine/threonine protein kinase that regulates a number of diverse biologic processes important for cell growth and proliferation, including ribosomal biogenesis and protein translation. In this regard, hyperactivation of the mTOR signaling pathway has been demonstrated in numerous human cancers, including a number of inherited cancer syndromes in which individuals have an increased risk of developing benign and malignant tumors. Three of these inherited cancer syndromes (Lhermitte-Duclos disease, neurofibromatosis type 1, and tuberous sclerosis complex) are characterized by significant central nervous system dysfunction and brain tumor formation. Each of these disorders is caused by a genetic mutation that disrupts the expression of proteins which negatively regulate mTOR signaling, indicating that the mTOR signaling pathway is critical for appropriate brain development and function. In this review, we discuss our current understanding of the mTOR signaling pathway and its role in promoting ribosome biogenesis and cell growth. We suggest that studies of this pathway may prove useful in identifying molecular targets for biologically-based therapies of brain tumors associated with these inherited cancer syndromes as well as sporadic central nervous system tumors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic / pharmacology
  • Antibiotics, Antineoplastic / therapeutic use
  • Brain Neoplasms / drug therapy
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Cell Proliferation* / drug effects
  • Central Nervous System / drug effects
  • Central Nervous System / metabolism*
  • Central Nervous System / pathology
  • Humans
  • Mutation
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Ribosomes / metabolism
  • Signal Transduction* / drug effects
  • Sirolimus / pharmacology
  • Sirolimus / therapeutic use
  • TOR Serine-Threonine Kinases


  • Antibiotics, Antineoplastic
  • Protein Kinase Inhibitors
  • Protein Kinases
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • Sirolimus