Fig. 4

The ER stress inhibitor 4-PBA counteracts CUB. a, b Western blot detected the protein levels of p-eIF2Α, CHOP Akt/mTOR/pS70k pathway, LC3B, and β-actin in GBM cells pretreated with 4-PBA (2 mM) for 12 h before exposure to CUB (20 µM)(Cropped blots, original cropped images and replicates are presented in Additional file 1: Fig. S8 and. S9). c Morphological images of U87 cells treated with CUB (10 µM), 4-PBA (2 mM), and CUB (10 µM) with 4-PBA (2 mM) together, respectively (Cropped blots). d Cell viability of GBM cells CUB (10 µM), 4-PBA (2 mM) and CUB (10 µM) with 4-PBA (2 mM) together. The scale bars were marked in the image. All data were the mean ± SEM of values from experiments performed in triplicate. * P < 0.05, ** P < 0.01 and *** P < 0.001 compared to control