Phosphatase and tensin homologue phosphorylation in the C-terminal regulatory domain is frequently observed in acute myeloid leukaemia and associated with poor clinical outcome.

Phosphorylation of PTEN (phosphatase and tensin homologue) affects PTEN protein stability and function. In this study, phosphorylated PTEN (pPTEN) was observed in 45 (73.8%) of 61 cases with acute myeloid leukaemia (AML). Phosphorylation of Akt and its downstream molecules [FKHR; Forkhead (Drosophila) homologue 1; and GSK-3beta; glycogen synthase kinase 3 beta] was significantly associated with pPTEN (P < 0.001). The complete remission rates were not different with respect to pPTEN, but overall survival was significantly shorter in patients with pPTEN (P < 0.05). Constitutive PTEN phosphorylation may add insight into the molecular pathogenesis of AML, and may be a new parameter for an unfavourable outcome.