Figure 6

Differential sensitivity of mTORC1/2 inhibitor and GSK3β inhibitor in PTEN^wt and PTEN^mu cells based on the existence of mTORC2. (a, b) PTEN^wt cells were transfected with siPTEN and after 24 h, they were treated with mahanine (0–15 uM). (a) The expression levels of phospho-AKT Ser473 were revealed by western blotting. (b) Dead cell population was determined by PI staining. (c, d) PTEN^mu cells were transfected with siRictor and after 24 h, they were treated with mahanine (0–15 μM). (c) Mahanine-mediated cell death was determined by PI-positive cells by flow cytometric analysis. (d) Light microscopic image showed the morphology of PTEN^mu cells after mahanine treatment. (e) Schematic diagram showed possible strategy to enhance the activity of mTORC1/2 inhibitor in GBM. (f, g) PTEN^mu and PTEN^wt cells were treated with mahanine (12 μM) and GSK3β inhibitor (SB216763, 20 μM). After 24 h of treatment, cells were processed for cell cycle analysis. Dead cell population was determined by PI staining by flow cytometry. Each value is the mean±s.d. of three independent experiments. *P<0.05, significant difference between two test groups. (h) Schematic representation: reciprocal responsiveness of mahanine and GSK3β inhibitor depending on existence of mTORC2 in PTEN^wt and PTEN^mu cells.