Figure 3. Bortezomib induces autophagy in JNK-dependent manner.

(A) BC3 and BCBL1 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-LC3, anti-pJNK, anti-T-JNK and anti-p62. Anti-β-actin was used as loading control. The histograms indicate LC3-II/I and LC3-II/Actin ratio based on densitometric analysis (mean ± the standard deviation, n = 3 experiments). (B) BC3 cells were transfected with DN-JNK expression vector or with an control empty vector (CV) and after 16 hrs treated with bortezomib (20 nM) for an additional 16 hrs. Total cell lysates were prepared and immunoblotted with anti-LC3 and p62 antibodies. β-actin was used as internal control. The histograms indicate LC3-II/I and LC3-II/Actin ratio based on densitometric analysis (mean ± the standard deviation, n = 3 experiments). (C) BC3 and BCBL1 cells were treated with Bortezomib (20 nM) alone or in combination with JNK inhibitor (SP600125) (20 µM) or ERK inhibitor (PD98059) (10 µM) for 16 hrs. A western blotting was performed using the following antibodies: anti-pBcl2(S70) and anti-total Bcl2. β-actin was used as loading control.