Figure 5.

IGF-1R silencing maintains metformin-induced TSC2 activation and mTOR inactivation in hyperglycemic conditions in SNU-245 and SNU-1196 cell. Cells were treated with either siRNA against IGR-1R or scrambled siRNA and incubated for 4 h. Afterwards, cells were treated with metformin in either 5 mM or 25 mM glucose-containing DMEM with 1% FBS for 24 h. Expression levels were analyzed by Western blotting. All results are representative of at least three separate experiments. IGF-1R silencing induced TSC-2 activation and mTOR inactivation without metformin treatment in FG conditions. However, IGF-1R silencing maintained metformin-induced TSC-2 activation and mTOR inactivation in HG conditions.