JNK/mTOR regulates GRP78 induction through ATF4 in human CCA cells.

(A) After treated with SP600125 (SP, 20 µM) for 48 h, ATF4 and phosphorylated eIF2α in QBC939, RBE and HCCC-9810 cells were analyzed using western blot. (B) After treated with rapamycin (Rap, 20 nM) for 48 h, phosphorylated eIF2α and phosphorylated p70S6K in QBC939, RBE and HCCC-9810 cells were analyzed using western blot. (C) After treated with salubrinal (Sal, 25 µM) for 30 h with or without SP600125 (SP, 20 µM) and rapamycin (Rap, 20 nM) preincubation for 1 h, ATF4 and phosphorylated eIF2α were analyzed using western blot in HepG2 cells. (D) After treated with PF-4708671 (PF, 10 µM) and 4EGI-1 (50 µM) for 48 h, GRP78 and ATF4 in QBC939, RBE and HCCC-9810 cells were analyzed using western blot. (E) QBC939, RBE and HCCC-9810 cells were treated with rapamycin (Rap, 20 nM) for 12 h, and ATF4 and GRP78 mRNA levels were analyzed using real-time RT-PCR. Values are means±S.D. Columns, mean of three individual experiments; bars, SD. *Significantly different from control value.