ZnO Nanoparticles Treatment Induces Apoptosis by Increasing Intracellular ROS Levels in LTEP-a-2 Cells

• Published in: BioMed research international 2015-01, Vol.2015 (2015), p.1-9
• Main Authors: Ji, Yinglu, Gao, Yan, Hu, Xiaoke, Wang, Caixia
• Format: Article
• Language: English
• Subjects: Adenocarcinoma; Adenocarcinoma - drug therapy; Adenocarcinoma of Lung; Antioxidants; Apoptosis; Apoptosis - drug effects; Assaying; Biomedical research; Cancer; Cancer cells; Cancer therapies; Cell culture; Cell Line, Tumor; Cell Survival - drug effects; Clinical trials; Colleges & universities; Cytoplasm - drug effects; Exposure; Glutathione - metabolism; Human; Humans; Lung Neoplasms - drug therapy; Metal Nanoparticles - administration & dosage; Metal Nanoparticles - chemistry; Metal oxides; Microscopy; Morphology; Nanomaterials; Nanoparticles; Oncology, Experimental; Oxidative stress; Oxidative Stress - drug effects; Physiological aspects; Reactive Oxygen Species - metabolism; Receiving; Zinc oxide; Zinc Oxide - administration & dosage; Zinc Oxide - chemistry; Zinc oxides
• ISSN: 2314-6133; 2314-6141
• DOI: 10.1155/2015/423287

Owing to the wide use of novel nanoparticles (NPs) such as zinc oxide (ZnO) in all aspects of life, toxicological research on ZnO NPs is receiving increasing attention in these days. In this study, the toxicity of ZnO NPs in a human pulmonary adenocarcinoma cell line LTEP-a-2 was tested in vitro. Log-phase cells were exposed to different levels of ZnO NPs for hours, followed by colorimetric cell viability assay using tetrazolium salt and cell survival rate assay using trypan blue dye. Cell morphological changes were observed by Giemsa staining and light microscopy. Apoptosis was detected by using fluorescence microscopy and caspase-3 activity assay. Both intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) were examined by a microplate-reader method. Results showed that ZnO NPs (≥0.01 μg/mL) significantly inhibited proliferation ( P < 0.05 ) and induced substantial apoptosis in LTEP-a-2 cells after 4 h of exposure. The intracellular ROS level rose up to 30–40% corresponding to significant depletion (approximately 70–80%) in GSH content in LTEP-a-2 cells ( P < 0.05 ), suggesting that ZnO NPs induced apoptosis mainly through increased ROS production. This study elucidates the toxicological mechanism of ZnO NPs in human pulmonary adenocarcinoma cells and provides reference data for application of nanomaterials in the environment.