TAK-243 blocks ubiquitin conjugation and induces ER stress and the UPR in DLBCL cells. (A) DLBCL cell lines were treated with the indicated doses of TAK-243 for 4 hours. Proteins were lysed and subjected to immunoblotting. (B) DLBCL cell lines were treated with TAK-243 for 24 hours. Apoptosis was determined by Annexin-V staining. Data are presented as mean ± standard error (SE). *P < .05 compared with untreated control. (C-D) DLBCL cells were treated with the indicated doses of TAK-243 for 4 hours (C) or as indicated (D), and proteins were lysed and subjected to immunoblotting. (E) OCI-LY3 cells were treated with TAK-243 for 4 hours. Total RNA was isolated, reverse transcribed, and subjected to RT-PCR with the indicated probes (in duplicates). Results were normalized to GAPDH levels. Data are presented as mean ± SE. *P < .05 compared with untreated control. GCB, germinal center B-cell–like.