Figure 1.

Downregulation of the activity of MEK1/2 or ERK1/2 inhibitedND-induced cell death. MEK1/2 activity was inhibited by its inhibitor PD98059 and ERK1/2 activity was inhibited by siRNA knockdown of ERK1/2 in MKN45 cells. Cells were transiently transfected with 25 nM siCTRL or siERK1/2. (A) Western blot demonstrating the knockdown of ERK1/2 by siRNA. (B) Following transfection (24 h), cells were treated with ND with or without PD98059 (20 µg/ml) for 4 or 8 h, and cell death was analyzed (n=3). *P<0.05. ND, nutrition deprivation; MEK1/2, dual-specificity mitogen-activated protein kinase kinase 1/2; ERK1/2, mitogen-activated protein kinase; siCTRL, siRNA control; siERK1/2, ERK1/2 siRNA.