title: Single-cell analysis of dihydroartemisinin-induced apoptosis through reactive oxygen species-mediated caspase-8 activation and mitochondrial pathway in ASTC-a-1 cells using fluorescence imaging techniques.
abstract: Dihydroartemisinin (DHA), a front-line antimalarial herbal compound, has been shown to possess promising anticancer activity with low toxicity. We have previously reported that DHA induced caspase-3-dependent apoptosis in human lung adenocarcinoma cells. However, the cellular target and molecular mechanism of DHA-induced apoptosis is still poorly defined. We use confocal fluorescence microscopy imaging, fluorescence resonance energy transfer, and fluorescence recovery after photobleaching techniques to explore the roles of DHA-elicited reactive oxygen species (ROS) in the DHA-induced Bcl-2 family proteins activation, mitochondrial dysfunction, caspase cascade, and cell death. Cell Counting Kit-8 assay and flow cytometry analysis showed that DHA induced ROS-mediated apoptosis. Confocal imaging analysis in a single living cell and Western blot assay showed that DHA triggered ROS-dependent Bax translocation, mitochondrial membrane depolarization, alteration of mitochondrial morphology, cytochrome c release, caspase-9, caspase-8, and caspase-3 activation, indicating the coexistence of ROS-mediated mitochondrial and death receptor pathway. Collectively, our findings demonstrate for the first time that DHA induces cell apoptosis by triggering ROS-mediated caspase-8/Bid activation and the mitochondrial pathway, which provides some novel insights into the application of DHA as a potential anticancer drug and a new therapeutic strategy by targeting ROS signaling in lung adenocarcinoma therapy in the future.
authors.affiliation: South China Normal University, Institute of Laser Life Science, MOE Key Laboratory of Laser Life Science, Guangzhou, China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Lu
authors.forename: Tong-Sheng
authors.initials: TS
authors.lastname: Chen
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Li
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000962:Antimalarials / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D037621:Artemisinins / Q000494:pharmacology*; D053181:Caspase 8 / Q000378:metabolism*; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D017382:Reactive Oxygen Species; C039060:artenimol; D053181:Caspase 8