PI3K/AKT/mTOR pathway

The PI3K/AKT/MTOR pathway is an intracellular signalling pathway important in apoptosis and hence cancer    (e.g. breast cancer and non-small-cell lung cancer) and longevity.



The PI3K/AKT/MTOR pathway contributes to hypertrophic muscle growth. It is activated by IGF1 and has a number of downstream effects which either promote protein synthesis or inhibit protein breakdown.

PI3K activation activates AKT which activates mTOR. ('PDK1' in the diagram is Phosphoinositide-dependent kinase-1.)

In many cancers, this pathway is overactive, thus reducing apoptosis and allowing proliferation. Consequently, some experimental cancer drugs aim to inhibit the signalling sequence at some point.

The PI3K pathway may be overactive because PTEN is faulty or deficient.