Abstract:Objective:To investigate the effects of the tumor suppressor gene PTEN in growing inhibition and down-regulating mTOR in cholangiocarcinoma QBC939 cells in vitro. Methods:QBC939 cells were transfected with plasmids wild-type PTEN and C124S-PTEN in vitro. After transfection, the expression of the PTEN and phosphorylation of AKT and mTOR was detected by Western blot. Flow cytometry was used to analyze apoptosis and cell cycle of the transfected cells. Results:Compared with the control, the expression of phosphorylation AKT was decreased and mTOR were down-regulated respectively when transfected with the wild-type PTEN. However, after transfection with mutation-type PTEN, the level of PTEN in the cells by increased, but phosphorylation AKT level and mTOR expression had no significant change.Conclusions:PTEN can be actived by phosphorylated AKT. Actived AKT decreased the mTOR which led to tumor cells apoptosis and regulation of the tumor cell cycle. In the pathway of signal transmission of PI3K/AKT/PTEN/mTOR, PTEN and mTOR are closely related through phosphorylation of AKT.