Fig. 6: The effect of STAG2 knockdown on the expression and protein stability of c-Myc.

a Western blot analysis of p-ERK, t-ERK, c-Myc and its downstream target NCL in STAG2-knockdown 8305C and 8505C cells and their control cells. b mRNA expression c-Myc was analyzed by qRT-PCR in the above cells. β-actin was used as an internal reference. c STAG2-knockdown 8305C and 8505C cells and their control cells were seeded and then treated with 200 μg/mL cycloheximide (CHX) for the indicated times. Next, lysates were prepared and then immunoblotted for the indicated proteins (left panels). The band intensity of c-Myc was normalized to that of GAPDH, and subsequently normalized to that in the DMSO-treated cells (right panels). d STAG2-knockdown 8305C and 8505C cells and their control cells were treated with 25 μM MG-132 4 h before harvesting, and then subjected to western blot analysis using the indicated antibodies. e The effect of STAG2 knockdown on the expression of HER3 and its downstream molecules was determined by western blot analysis using the indicated antibodies. f Western blot analysis of the indicated proteins in STAG2-knockdown 8305C cells and control cells treated with or without MEK inhibitor GSK1120212 (GSK). g Lysates from STAG2-knockdown and control tumors were subjected to western blot analysis using the indicated antibodies. h Representative tumor sections from STAG2-knockdown and control mice were subjected to IHC assay using the indicated antibodies with quantitative analysis using AOD value. Scale bar, 200 μm. Data are presented as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001.