Figure 6. Effects of combined AKT and ERK inhibition on SK-N-SH cell death and GAPDH nuclear accumulation.
Untransduced SK-N-SH cells were treated in the absence and presence of either 10 μM U0126 (MEK inhibitor) and/or 20 μM AKTi. Cells exposed to both inhibitors were also treated with 25 nM deprenyl. (a) Concurrent inhibition of AKT and ERK significantly increases cell death but not GAPDH nuclear accumulation. Cell death was quantified as in Figure 1b (upper graph). Data represent means ± SEM, n=3. Analysis of cytoplasmic and nuclear fractions was performed as in Figure 3a (bottom panels). (b) Immunoblotting of whole cell lysates with the indicated antibodies, prepared from cells treated with or without AKTi and/or U0126. (c) Overexpression of a constitutively active AKT mutant (myr-AKT) blocks cell death in CIB1-depleted cells. Cell viability was quantified as Figure 1b. Data represent +/- SEM, n=3. Expression of myr-AKT blocks GAPDH nuclear accumulation (lower panels). Nuclear lysates were immunobloted with anti-GAPDH or -lamin A/C antibodies.