TNF-α up-regulates Bcl-6 expression. (A) MM.1S and U266 cells were cultured with IL-6 (5 ng/mL) or SCCSs (SC) for 12 hours. (B) RPMI8226 cells were cultured with 3 different SCCS (#1, #2, #3) for 12 hours. (C) RPMI8226 cells were cultured with tumor necrosis factor-α (TNF-α; 2.5 ng/mL) or IL-6 (5 ng/mL) for the indicated time periods. (D) Patient MM cells were cultured with IL-6 (5 ng/mL), TNF-α (2.5 ng/mL), or SCCSs (SC) for 12 hours. (E) RPMI8226 cells were cultured with or without SCCSs (S), in the presence or absence of MLN120B (M, 10μM) for 12 hours. (F) Patient MM cells were cultured with TNF-α (T) for 12 hours in the presence or absence of MLN120B (M, 10μM). (G) RPMI8226 cells were cultured with 3 different SCCSs (sc#1, sc#2, and sc#3), in the presence or absence of neutralizing IL-6 antibodies (5 μg/mL) or MLN120B (M, 10μM) for 12 hours. Whole cell lysates were subjected to immunoblotting with indicated antibodies.