FIGURE 3.

mTOR regulates transcription of PTEN in TSC2^−/− MEFs and 293 cells. A and B, TSC2^−/− MEFs were transfected with PTEN-Luc along with mTOR KD as indicated. Twenty-four hours post-transfection, the cells were serum-starved for 24 h and treated with rapamycin for 24 h before harvesting (A). Luciferase activity was determined in the cell lysates as described under “Experimental Procedures” (41, 44, 45, 65). C–E, 293 cells were transfected with PTEN-Luc along with mTOR KD or CA mTOR as indicated followed by incubation in the presence of serum for 48 h (C and D). The cells in C were incubated with rapamycin for 24 h before harvesting. For E, 24 h post-transfection, the cells were incubated in serum-free medium for 24 h. The cell lysates were used for luciferase activity assay as described (41, 44, 45, 65). For A–D, mean ± S.E. of 12 measurements is shown. For A, B, and D, * represents p = 0.001 versus control. For C, * represents p = 0.002 versus control. For E, mean ± S.E. of six measurements is shown. *, p = 0.0007 versus control.