Daurisoline Inhibits ESCC by Inducing G1 Cell Cycle Arrest and Activating ER Stress to Trigger Noxa-Dependent Intrinsic and CHOP-DR5-Dependent Extrinsic Apoptosis via p-eIF2α-ATF4 Axis

Figure 7

ROS-dependent activation of the p-eIF2α-ATF4 axis was essential for daurisoline-induced apoptosis. (a) EC1 and ECA109 cells were treated with DAS as described above, and proteins were subjected to western blot. (b-d) EC1 and ECA109 cells were transfected with control or two siRNA sequences of eIF2α, then treated with DAS (30 μM) for 24 hours. Apoptosis induction was quantified by Annexin V-FITC/PI double-staining and FACS analysis. Proteins were extracted and detected by western blot. The mRNA level of CHOP, DR5, and Noxa was quantified by Q-PCR. (e, f) EC1 and ECA109 cells were treated with indicated concentrations of DAS or DAS (40 μM) and NAC (10 mM) for 24 hours, and ROS generation was determined by DCFH-DA staining and FACS analysis. Proteins were extracted and detected by western blot.

(a)

(b)

(c)

(d)

(e)

(f)