title: Hoechst 33342-induced autophagy protected HeLa cells from caspase-independent cell death with the participation of ROS.
abstract: Autophagy, an evolutionarily-conserved intracellular organelle and protein degradation process, may exhibit drastically different effects on cell survival depending on the particular environmental and culturing conditions. Hoechst 33342 (HO), a fluorescent dye widely used for staining DNA, has been reported to induce apoptosis in mammalian cells. Here we showed that, in addition to caspase-independent cell death, HO also induced autophagy in HeLa cells, as evidenced by the accumulation of autophagosomes, LC3 form conversion and LC3 puncta formation in a cell line stably expressing GFP-LC3. HO treatment led to generation of reactive oxygen species (ROS), and inhibition of ROS with N-acetyl-l-cysteine (NAC) abrogated both autophagy and caspase-independent cell death. Finally, autophagy played a protective role against caspase-independent cell death, as cell death induced by HO was enhanced under pharmacological and siRNA-mediated genetic inhibition of autophagy.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale & School of Life Sciences, University of Science and Technology of China, Anhui, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zheng
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Yang
authors.forename: Ke-Jing
authors.initials: KJ
authors.lastname: Sun
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Wan
authors.forename: Na
authors.initials: N
authors.lastname: Man
authors.forename: Long-Ping
authors.initials: LP
authors.lastname: Wen
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D001343:Autophagy / Q000187:drug effects* / Q000502:physiology; D001562:Benzimidazoles / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D008854:Microscopy, Electron; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014162:Transfection
chemical_list: D001562:Benzimidazoles; D017382:Reactive Oxygen Species; D020169:Caspases; C017807:bisbenzimide ethoxide trihydrochloride; D000111:Acetylcysteine