The expression of PTEN in HEK293 cells induces apoptosis and cell cycle arrest

It was to study whether overexpression of the tumor suppressor PTEN in HEK293 cells could lead to apoptosis and cell cycle arrest. The wild-type and mutant T910G of PTEN expression plasmids were constructed and transfected into PTEN-null HEK293 cells respectively. Apoptosis was evaluated by the appearance of cytosolic low molecular DNA ladder on the gel. Cell cycle was determined by flow-cytometric analysis. The Western blot analysis was performed to determine the phosphorylation levels of PKB/Akt and MAPK. The present data showed that the overexpression of PTEN in HEK293 cells could induce apoptosis and resulted in an increase in G1 cell population through inhibiting PKB/Akt and MAPK phosphrylation stimulated by PDGF. Mutant PTEN cause less apoptosis and G1 arrest than wild-type PTEN. MAPK dephosphorylation caused by mutant PTEN was not so significant as by wild-type PTEN. These data suggested that PTEN may exert its tumor-suppressive effects through both the inhibition of cell cycle progression and the induction of apoptosis.