Rosmarinic acid suppresses cell proliferation and induces apoptosis of human nasopharyngeal carcinoma cell line CNE-1

YANG Peilin; GAO Ling; LIN Caixia; WANG Wei; XU Liba; WU Lingling; JIANG Weizhe; JIAO Aijun

doi:10.3969/j.issn.1002-266X.2017.36.001

Abstract：Objective To investigate the effects of rosmarinic acid (RA) on cell proliferation and apoptosis of human nasopharyngeal carcinoma cell line CNE-1 and to identify its possible mechanism.Methods The human nasopharyngeal carcinoma cells line CNE-1 were cultured in vitro and the cells of the third generation in the logarithmic phase were randomly divided into the blank control group and RA (10,20,30 μmol/L) treatment groups.The cells of the RA groups were cultured in nutrient solutions with different concentrations of RA,and cells in the blank control group were cultured in the same nutrient solution without RA.Each group was cultured for 24 h,48 h,and 72 h,respectively.And then the cellular growth inhibition rate in each group was determined by MTT.After CNE-1 cells were incubated with RA for 48 h,we found that the relationship between concentration changes of RA and the rate of cellular growth inhibition was better than others.Therefore,the following experiment was carried out after CNE-1 cells were incubated with RA for 48 h.After that,the morphological changes of the cells were observed under a fluorescence microscope with Hoechst 33258 staining.The apoptosis rate was detected by using flow cytometry with Annexin V-FTIC/PI staining,and the protein expression of PTEN,PI3K/ Akt/mTOR signaling pathway was detected by Western blotting,respectively.Results Compared with the blank control group,RA inhibited the proliferation of human nasopharyngeal carcinoma cell line CNE-1 in a dose-and time-dependent manner (P ＜ 0.05).Cells showed typical apoptosis state change and the apoptosis rate showed the way of dose-dependent manner after treatment by RA.The apoptosis rate of each RA treatment group was significantly higher than that of the blank control group (all P ＜ 0.05).Meantime,there was significant difference in the apoptosis rate among the RA treatment groups (all P ＜ 0.05).Compared with the blank control group,the protein expression of PTEN was up-regulated while the expression of p-PI3K,p-Akt,and p-mTOR were down-regulated (all P ＜ 0.05),whereas the expression of PI3K,Akt,and mTOR were not significantly changed (all P ＞ 0.05).Conclusion RA could inhibit the cell proliferation and induce the apoptosis of human nasopharyngeal carcinoma cell line CNE-1 with a dose-dependent manner by regulating the PI3K/ Akt/mTOR signal transduction pathway.