BIX-01294 induces autophagy-associated cell death via EHMT2/G9a dysfunction and intracellular reactive oxygen species production.

BIX-01294 induces autophagy-associated cell death via EHMT2/G9a dysfunction and intracellular reactive oxygen species production. Autophagy. 2013 Dec 1;9(12):2126-39 Authors: Kim Y, Kim YS, Kim DE, Lee JS, Song JH, Kim HG, Cho DH, Jeong SY, Jin DH, Jang SJ, Seol HS, Suh YA, Lee SJ, Kim CS, Koh JY, Hwang JJ Abstract We screened a chemical library in MCF-7 cells stably expressing green fluorescent protein (GFP)-conjugated microtubule-associated protein 1 light chain 3 (LC3) (GFP-LC3-MCF-7) using cell-based assay, and identified BIX-01294 (BIX), a selective inhibitor of euchromatic histone-lysine N-methyltransferase 2 (EHMT2), as a strong autophagy inducer. BIX enhanced formation of GFP-LC3 puncta, LC3-II, and free GFP, signifying autophagic activation. Inhibition of these phenomena with chloroquine and increasement in punctate dKeima ratio (550/438) signal indicated that BIX activated autophagic flux. BIX-induced cell death was suppressed by the autophagy inhibitor, 3-methyladenine, or siRNA against BECN1 (VPS30/ATG6), ATG5, and ATG7, but not by caspase inhibitors. Moreover, EHMT2 siRNA augmented GFP-LC3 puncta, LC3-II, free GFP, and cell death, implying that inhibition of EHMT2 caused autophagy-mediated cell death. Treatment with EHMT2 siRNA and BIX accumulated intracellular reactive oxygen species (ROS). BIX augmented mitochondrial superoxide via NADPH oxidase activation. In addition, BIX increased hydrogen peroxide and glutathione redox poten...
Source: Autophagy - Category: Cytology Authors: Tags: Autophagy Source Type: research