title: CdSe quantum dots induce apoptosis in human neuroblastoma cells via mitochondrial-dependent pathways and inhibition of survival signals.
abstract: Quantum dots (QDs) may be useful as novel luminescent markers, but their cytotoxicity has not been fully investigated. In this report, we demonstrate that CdSe-core QDs can induce apoptotic biochemical changes, including JNK activation, loss of mitochondrial membrane potential, mitochondrial release of cytochrome c and activation of caspase-9 and caspase-3 in the IMR-32 human neuroblastoma cell line. Importantly, treatment of IMR-32 cells with CdSe-core QD triggered an increase in reactive oxygen species (ROS) and inhibited survival-related signaling events, such as decreased Ras and Raf-1 protein expression and decreased ERK activation. These apoptotic biochemical changes were not detected in cells treated with ZnS-coated CdSe QDs. Collectively, these results demonstrate that CdSe-core QD treatment of IMR-32 cells induced JNK activation and mitochondrial-dependent apoptotic processes while inhibiting Ras-->ERK survival signaling and that a ZnS coating could effectively reduce QD cytotoxicity.
authors.affiliation: Department of Bioscience Technology, Center for Nanotechnology, Chung Yuan Christian University, Chung Li, Taiwan. whchan@cycu.edu.tw
authors.forename: Wen-Hsiung
authors.initials: WH
authors.lastname: Chan
authors.forename: Nion-Heng
authors.initials: NH
authors.lastname: Shiao
authors.forename: Pin-Zhen
authors.initials: PZ
authors.lastname: Lu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D019187:Cadmium Compounds / Q000633:toxicity*; D053148:Caspase 3 / Q000502:physiology; D053453:Caspase 9 / Q000502:physiology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000502:physiology; D008928:Mitochondria / Q000502:physiology*; D009447:Neuroblastoma / Q000473:pathology*; D045663:Quantum Dots; D017382:Reactive Oxygen Species; D018036:Selenium Compounds / Q000633:toxicity*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D019187:Cadmium Compounds; D018841:HSP90 Heat-Shock Proteins; D017382:Reactive Oxygen Species; D018036:Selenium Compounds; C058667:cadmium selenide; D048031:JNK Mitogen-Activated Protein Kinases; D053148:Caspase 3; D053453:Caspase 9