Fig. 4

FASNi modulates autophagy upon proteasome inhibition and leads to synergistic cell death in MCL cells. a Co-treatment of bortezomib with the fatty acid synthase inhibitor orlistat blocks autophagy. MCL cell line Mino was treated with 15 μM orlistat and 7 nM bortezomib. After 8 h, samples were harvested for Western blot analysis. b Inhibition of proteasome and fatty acid synthase further increases NOXA half-life. MCL cell line Jeko-1 was treated with 15 μM orlistat and 7 nM bortezomib. After 14 h, 20 μg/ml cycloheximide was added to the cells and samples were harvested 0, 30, 45, 60, 90, 120, and 180 min after cycloheximide exposition for Western blot analysis (upper panel) and quantification of NOXA protein stability (lower panel). c Co-treatment of bortezomib with orlistat induces cell death in MCL cell lines. MCL cell lines were treated with 15 μM orlistat and 7 nM (Jeko-1 and Rec-1) or 5 nM (Mino and Jvm2) bortezomib. After 14 h, protein expression was analyzed (Jeko-1), and after 24 h, cell death was assessed by AnnexinV-PI staining. d Co-treatment of bortezomib with orlistat induces cell death in primary MCL cells. Primary MCL cells were treated with 15 μM orlistat and 7 nM (four patients, upper panel) or 5 nM (six patients, lower panel) bortezomib. After 24 h, samples were taken for Western blot analysis (left) and cell death was assessed by AnnexinV-PI staining (right). e Healthy lymphocytes and monocytes are hardly affected by co-treatment of proteasome inhibitors with orlistat. Peripheral blood mononuclear cells were treated with 15 μM orlistat and 5 nM or 7 nM bortezomib. After 24 h, cell death was assessed by AnnexinV-PI staining. Data represent means ± S.D. from three independent experiments