Endoplasmic reticulum stress sensitizes human esophageal cancer cell to radiation

Figure 4 Autophagy response induced by tunicamycin. A: EC109 cells were exposed to increasing concentrations of tunicamycin (TM), and stained with acridine orange (AO); B: EC109 cells were pretreated with or without TM (5 μg/mL), followed by a single dose of 10 Gy and analyzed by Western blotting for LC3 and ATG5; C: Relative mRNA expression of Beclin-1 and ATG5 was assessed by quantitative polymerase chain reaction; D: After AO staining, cells were quantitatively analyzed on a FACSort; E: Cells were treated as indicated, and protein levels of LC3 and ATG5 were assessed by Western blotting; F: Relative cell viability of cells treated with TM, radiation and autophagy inhibitor 3-MA for 24 or 48 h. N: Sham-treated with TM; R: 10 Gy irradiation. GAPDH: Glyceraldehyde-3-phosphate dehydrogenase.