TAK-243 induces ER stress and apoptosis in primary DLBCL cells. (A) Primary DLBCL cells were cocultured with CD40L-expressing or control stroma for 24 hours, then treated with then indicated concentrations of TAK-243 for additional 24 hours. Apoptosis of the CD19-positive B cells was assessed by Annexin V staining. Data are presented as mean ± SE. (B-C) DLBCL cells (n = 3) were cocultured with the CD40L-expressing stroma for 24 hours and then treated with the indicated concentrations of TAK-243 for 2 and 4 hours. (B) Cells were harvested for protein lysates (analyzed by immunoblotting) and RNA. (C) Transcript mRNA levels were quantitated by quantitative RT-PCR, and fold change was measured against cells treated with vehicle control. *P < .05; **P < .01.