Effects of epigallocatechin gallate on the proliferation and apoptosis of the nasopharyngeal carcinoma cell line CNE2

The present study explored the effects of epigallocatechin gallate (EGCG) on the cell cycle, proliferation and apoptosis of the nasopharyngeal carcinoma cell line CNE2 in vitro. The proliferation of CNE2 cells was detected using the cell counting kit-8 method. Cell cycle distribution and apoptosis were detected using flow cytometry. The human telomerase reverse transcriptase (hTERT) mRNA expression was determined using reverse transcription polymerase chain reactions. The protein expression of hTERT and Myc proto-oncogene protein (c-Myc) was observed using western blot analysis. EGCG inhibited the proliferation of CNE2 cells in a concentration-dependent manner (P<0.05) and blocked the cell cycle progression of the cells. In the low concentration (100 μg/ml) group, the cell cycle arrest showed a time-dependent manner. However, as the concentration increased and action time was prolonged, this time dependency became less marked. EGCG promoted the apoptosis of CNE2 cells in a time-dependent manner. In addition, EGCG downregulated the mRNA and protein expression of hTERT and downregulated the expression of c-Myc protein. Downregulation of the expression of hTERT and c-Myc was more evident in the high-dose group (200 μg/mL). In conclusion, EGCG has proliferation-inhibiting, cell cycle-blocking and apoptosis-promoting effects on CNE2 cells. EGCG may be developed into an auxiliary therapeutic agent for the treatment of nasopharyngeal carcinoma.