AKT2 regulated N-myc expression.

<p>(<b>A</b>) BE(2)-C cells were transfected with siRNA pools specifically targeting siAKT1, siAKT2, and siAKT3. Cells were serum-starved for overnight 48 h after transfections, and then stimulated with IGF-1 (100 nM) for 2 h. N-myc expression was examined by Western blotting. Notably, only siAKT2 decreased N-myc expression. Knockdown efficiency of each isoform was confirmed at 48 h post-transfection. (<b>B</b>) N-myc expression was examined in stably-transfected BE(2)-C/shCON and BE(2)-C/shAKT2 cells using Western blotting. N-myc expression was reduced in AKT2 stably knockdown cells. (<b>C</b>) BE(2)-M17 and SK-N-BE(2) cells were transiently transfected with AKT2 siRNA (siAKT2) pool. Proteins were extracted from cells 72 h after transfected with siAKT2. N-myc expression was downregulated in siAKT2 cells as examined by Western blot analysis. (<b>D</b>) BE(2)-C cells were transiently transfected with siAKT2 for 24 h, then serum-starved for another 24 h. They were then treated with either GRP (100 nM) or IGF-1 (100 nM) for 2 h. Western blotting showed suppression of N-myc by siAKT2 despite stimulation with GRP or IGF-1. (<b>E</b>) BE(2)-C cells were transiently transfected with the AKT2 overexpression plasmid pcDNA-Myr-AKT2 (pAKT2) or a control plasmid pcDNA for 48 h. AKT2 overexpression was confirmed by Western blot analysis. N-myc expression increased, but GRP-R was not changed in AKT2 overexpressed cells.