Tunicamycin induces terminal/proapoptotic ER stress. (A,B) Time- and dose-dependent induction of gene expression using relative quantitative RT-PCR (qPCR) in BCWM.1 cells treated with tunicamycin, 4 μg/mL for 24 and 48 hours and 10 μg/mL for 3 and 6 hours, respectively. All data represent mean plus or minus SD of triplicate experiments. (A) Expression of genes of the IRE1 pathway, including IRE1, Xbp-1s, and EDEM. (B) Expression of genes of the PERK pathway, including PERK and GADD153/CHOP. (C) Dose-dependent induction of terminal/proapoptotic ER stress proteins. BCWM.1 cells were cultured with tunicamycin (0.1 μg/mL to 5 μg/mL) for 6 hours. Whole-cell lysates were subjecting to Western blotting using anti-GADD153/CHOP, -GRP78/BiP, -ATF6, -p-PERK, -EDEM, and α-tubulin antibodies. (D,E) Bortezomib-induced ER stress in WM disease. (D) We studied expression at the transcriptional level of ATF6, GRP78/BiP, PERK, GADD153/CHOP, IRE1, and Xbp-1s following treatment of BCWM.1cells for 6 hours with 20 ng/mL bortezomib. (E) Induction of terminal/proapoptotic ER stress proteins was also studied in BCWM.1 cells cultured with 20 ng/mL bortezomib for 6 hours. Whole-cell lysates were subjected to Western blotting using anti-GADD153/CHOP, -GRP78/BiP, -ATF6, -p-PERK, -EDEM, and α-tubulin antibodies.