Phosphatase and tensin homolog (PTEN) (PTEN)

Phosphatase and tensin homolog (PTEN) is a dual-specificity phosphatase that serves as a critical tumor suppressor by negatively regulating the PI3K/Akt/mTOR signaling pathway [1, 6, 16]. It primarily functions at the cell membrane, where it dephosphorylates the lipid second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) into phosphatidylinositol 4,5-bisphosphate (PIP2), thereby preventing the activation of AKT and downstream effectors that drive cell growth, survival, and proliferation [1, 15, 18]. PTEN is frequently inactivated in human cancers through mutation, deletion, or epigenetic silencing, leading to constitutive pathway activation and tumorigenesis [14, 15, 21]. In addition to its cytoplasmic role, PTEN also localizes to the nucleus, where it participates in maintaining genomic integrity through DNA repair and chromosomal stability [6, 12, 16]. Therapeutic strategies in PTEN-deficient contexts often focus on inhibiting pathway nodes like PI3K, AKT, and mTOR, while research is ongoing into PTEN-activating compounds and stabilization therapies [4, 8, 13, 20].

Other names

Mutated in multiple advanced cancers 1MMAC1TGF-beta-regulated and epithelial cell-enriched phosphatase 1TEP1Bannayan-Riley-Ruvalcaba syndromeBZSCowden syndrome 1CWS1MHAM10q23del

PTEN dephosphorylates PIP3 to PIP2, directly opposing the PI3K/AKT/mTOR signaling cascade [1, 15, 18]. Drugs like PI3K and mTOR inhibitors target downstream effectors to counteract the consequences of PTEN loss, while experimental PTEN activators and stabilizers aim to restore or enhance endogenous phosphatase function [4, 8, 9, 13].