The Akt-mTOR tango and its relevance to cancer

Cancer Cell. 2005 Sep;8(3):179-83. doi: 10.1016/j.ccr.2005.08.008.


The downstream effector of PI3K, Akt, is frequently hyperactivated in human cancers. A critical downstream effector of Akt, which contributes to tumorigenesis, is mTOR. In the PI3K/Akt/mTOR pathway, Akt is flanked by two tumor suppressors: PTEN, acting as a brake upstream of Akt, and TSC1/TSC2 heterodimer, acting as a brake downstream of Akt and upstream of mTOR. In the absence of the TSC1/TSC2 brake, mTOR activity is unleashed to inhibit Akt via an inhibitory feedback mechanism. Two recent studies used mouse genetics to assess the roles of PTEN and TSC2 in cancer, underscoring the importance of Akt-mTOR interplay for cancer progression and therapy.

Publication types

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

MeSH terms

  • Animals
  • GTP Phosphohydrolases / metabolism
  • Humans
  • Models, Biological
  • Neoplasms / enzymology*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Protein Kinases / metabolism*
  • Protein Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases


  • Proto-Oncogene Proteins
  • Protein Kinases
  • MTOR protein, human
  • mTOR protein, mouse
  • AKT1 protein, human
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • GTP Phosphohydrolases