PTEN [6H2.1]

PTEN (phosphatase and tensin homolog deleted on chromosome ten) is a tumor suppressor gene that is mutated in a wide range of cancers. PTEN is located on chromosome sub-band 10q23.3 and encodes a 403 amino acid protein which acts as a dual-specific protein and phospholipid phosphatase. As a lipid phosphatase, PTEN regulates phosphatidylinositol-3’-kinase by dephosphorylating the D3 position of phosphatidylinositol (3,4,5)-triphosphate and phosphatidylinositol (3,4)-biophosphate substrates, thereby antagonizing signal transduction downstream of phosphatidylinositol-(PI-3) kinase.7 Loss-of-function mutations in the PTEN gene lead to constitutive activation of multiple signaling pathways including the PI3K/Akt pathway which affects cell proliferation, apoptosis and migration. PTEN has also been shown to control p53 protein levels and transcriptional activity.