Figure 5. Inhibition of autophagy with 3-MA or with JNK inhibitor increases the Bortezomib anti-proliferative effect in JSC1 and BC1 PEL cells.

(A) Viability assay evaluated by trypan blue exclusion was performed in JSC1 (left panel) and BC1 (right panel) cells treated with bortezomib (20 nM) or 3-MA (5 mM) or SP600125 (20 µM) alone or in combination for 16 hrs. Mean ± the standard deviation was also indicated (n = 3 experiments). * p-value  =  0.05, ** p-value  =  0.05, ♦p-value  =  0.01, ♦♦p-value  =  0.02. Western blotting analysis was performed on JSC1 and BC1 cells to evaluate the expression of cleaved (cl) PARP p85 fragment. β-actin was used as loading control (middle panel). JSC1 and BC1 cells were treated with bortezomib (20 nM for 16 hrs) with or without pre-treatment with JNK inhibitor (SP600125) (20 µM). Total cell lysates were prepared and immunoblotted with the following antibodies: anti-pJNK, anti-T-JNK, anti LC3I/II and anti p62. Anti-β-actin was used as loading control.