Abstract: Objective To explore the relationship between mitochondrial damage and mitophagy in nasopharyngeal carcinoma CNE-1 cells treated with acetylated emodin derivative. Methods CNE-1 cells were divided into a control group and groups treated with 5 or 10 mg·L^-1 of acetylated emodin derivative.After treatment， autophagosome ultrastructure was analyzed by transmission electron microscopy，while mitochondrial membrane potential and levels of intracellular free calcium ion and reactive oxygen species were measured by confocal microscopy. Results Cells treated with acetylated emodin derivative showed mitochondrial damage and the presence of mitophagosomes，which were not observed in control cells.The emodin derivative also led to a significant decrease in mitochondrial membrane potential and increases in levels of intracellular free calcium ion and reactive oxygen species（P<0.05）；these effects were dose-dependent. Analyzing mitochondrial and lysosome markers of treated cells revealed typical mitophagic features， including acidic lysosomal proliferation and lysosomes containing mitochondrial remnants labeled with Mito Tracker Green. The abundance of these features was also dose-dependent. Conclusion The acetylated emodin derivative can cause mitochondrial damage in nasopharyngeal carcinoma CNE-1 cells，perhaps through a mechanism closely related to mitophagy.

Key words: Nasopharyngeal neoplasm, Acetylated emodin derivative, Mitophagy, Transmission electron microscopy, Confocal laser scanning microscopy