Isoimperatorin Induces Apoptosis of Nasopharyngeal Carcinoma Cells via the MAPK/ERK1/2 Signaling Pathway

Abstract

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 μM, 20 μM, 30 μM, and 40 μM) significantly inhibited the nasopharyngeal carcinoma CNE2 cell proliferation, and 48 h later, the inhibitory effect of the 40 μM treatment was significantly higher than that of 10 μM and 20 μM. 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.