Abstract: Objective To investigate the effects of chloroquine diphosphate (CDP) and rapamycin at different concentration on autophagy of CNE-2 cells. Methods Western-blot were used to detect the expression level of autophagy-related protein LC3-II (microtubule-associated protein 1 light chain 3，MAP1-LC3-II) and p62 in nasopharyngeal carcinoma cell line CNE-2 that were treated with CDP and rapamycin at different concentrations.Propidium iodide (PI) staining was used to detect the apoptosis rate of CNE-2 cells.Results Among the CDP-treated groups，the expression levels of LC3-II and p62 increased more pronouncedly when CNE-2 cells were treated at the concentration of 20.60mg/L (P＜0.01).Among the rapamycin-treated groups，18.28μg/L group showed increased expression of LC3-II (P＜0.01) and reduced expression of p62 (P＜0.01).The apoptosis rates in 20.60mg/L CDP group and 18.28μg/L rapamycin group were not statistically different from that of the control group (P＞0.05).Conclusions Chloroquine diphosphate can inhibit autophagy of CNE-2 cells at the concentration of 20.60mg/L.Rapamycin can induce autophagy at the concentration of 18.28μg/L.Both of them do not affect the apoptosis rate of CNE-2 cells.

Key words: Chloroquine diphosphate, Rapamycin, Autophagy, CNE-2 cells