Objective . To investigate the effect of isoimperatorin on nasopharyngeal carcinoma CNE2 cell apoptosis and the role of the MAPK/ERK1/2 signaling pathway in inducing apoptosis. Methods. Real-time cellular analysis technology (RTCA) and MTT were used to detect cell proliferation; Annexin V-FITC/PI dual-fluorescence flow cytometry analysis, Hoechst 33342 staining, and mitochondrial membrane potential detection kit were used to detect cell apoptosis; western blot was used to detect protein expression. Results . Different concentrations of isoimperatorin (10 μ M, 20 μ M, 30 μ M, and 40 μ M) significantly inhibited the nasopharyngeal carcinoma CNE2 cell proliferation, and 48 h later, the inhibitory effect of the 40 μ M treatment was significantly higher than that of 10 μ M and 20 μ M. Treatment for 48 h significantly induced nasopharyngeal carcinoma cell apoptosis and resulted in nuclear pyknosis and fragmentation. At the same timepoint, the expression levels of proliferation-related protein PCNA as well as antiapoptosis proteins XIAP, survivin, and Bcl-2 were decreased by drug treatment, the expression level of proapoptosis protein Bax was increased, and the expression of the key MAPK/ERK1/2 signaling pathway proteins p-c-Raf, p-MEK, and p-ERK1/2 of were decreased. After activation of the MAPK/ERK1/2 signaling pathway by isoprenaline hydrochloride (ISO), the efficacy of isoimperatorin to downregulate p-c-Raf, p-MEK, and p-ERK1/2 expressions in the MAPK/ERK1/2 signaling pathway and proliferation-related protein PCNA as well as antiapoptosis proteins XIAP, surviving, and Bcl-2 was reduced compared with that of isoimperatorin alone, the effect of upregulating the proapoptotic protein Bax was reduced, and the apoptosis rate was also decreased. Conclusion . Isoimperatorin can induce nasopharyngeal carcinoma CNE2 cell apoptosis through the MAPK/ERK1/2 signaling pathway. National Natural Science Foundation of China 81874408 Natural Science Foundation of Hunan Province 2019JJ40216 2017JJ3246
