Nuclear PTEN-mediated growth suppression is independent of Akt down-regulation.

The tumor suppressor gene PTEN is a phosphoinositide phosphatase that is inactivated by deletion and/or mutation in diverse human tumors. Wild-type PTEN is expressed both in the cytoplasm and nucleus in normal cells, with a preferential nuclear localization in differentiated or resting cells. To elucidate the relationship between PTEN's subcellular localization and its biologic activities, we constructed different PTEN mutants that targeted PTEN protein into different subcellular compartments.