[Signifinace of cyclin D1 expression in CNE2 cells processed by EGCG].

OBJECTIVE: To study the expression of Cyclin D1 in nasopharyngeal carcinoma cells processed by epigallocatechin gallate(EGCG) and it's significance, and revealed the anti-tumor mechanism of EGCG against nasopharyngeal carcinoma. METHOD: CNE-2 cells were treated by EGCG at different concentrations, the morphological changes of CNE-2 cells were observed by inverted microscope; the inhibition ratio of cell proliferation was detected by MTT colorimetric method, flow cytometry was used to analyze the changes of cell cycle. The expression of Cyclin D1 mRNA was detected by RT-PCR. RESULT: After treated by EGCG, the CNE2 cells decreased in amount and density, some of which became roll and small; Floating and dead cells can be seen in the inverted microscopy; cell proliferation was significantly inhibited in a time and dose dependent (P < 0.05). CNE-2 cells were arrested at G1/G0 phase. The expression of Cyclin D1 mRNA was down-regulated by EGCG with concentration and action time dependent (P < 0.05). CONCLUSION: EGCG resisted nasopharyngeal carcinoma by inhibiting the cell proliferation, The down regulation of Cyclin D1 mRNA expression in a time and dose dependent may be the possible mechanisms.