In summary, these results suggest that PDK1 may contribute to breast cancer, even in the absence of PI3K oncogenic mutations and through both Akt-dependent and Akt-independent mechanisms.
3-phosphoinositide dependent protein kinase-1 (PDK1), a transducer protein that functions downstream of PI3K, is responsible for the regulation of cell proliferation and migration and it also has been found to play a key role in different cancers, pancreatic and breast cancer amongst others.
In severe combined immunodeficiency mice, PDK1-depleted human breast cancer cells formed more slowly growing tumors and were defective in extravasation to mouse lungs after i.v. injection.
The phosphorylation of FAK, mTOR, p70S6K, and PDK-1 were elevated in both breast cancer cell lines, whereas the phosphorylation of AKT, EGFR, ErbB2/Her2, PDGFR, Shc, and Stat3 were elevated in only one breast cancer line compared to normal primary mammary epithelial cells and telomerase-immortalised breast epithelial cells.