The Changes Expression Of Protein And The Role Of STAT3, CyclinD1in EGCG Antisense Nasopharyngeal Carcinoma CNE2Cell Line

Objective：Nasopharyngeal carcinoma（NPC）is highly malignant tumors of headand neck. It has been found all the continents of the world， in Europe,America,Oceania and Latin America is less, Southeast Asia is high, but Japan andKorea nasopharyngeal carcinoma incidence is less than1/10million. It is acommon malignant tumor in our country，and the distribution has significant localdifferences. But the incidence of NPC in Guangdong, Guangxi, Fujian and Hunanprovince is higher. The mainly treatment of the nasopharyngeal carcinoma isradiotherapy, and combined with chemotherapy or operation with comprehensivetreatment. Comprehensive treatment for stage I patients of5years survival ratewas95%, and patients with stage IV is only35%. A large number of studies showthat epigallocatechin gallate can effectively reduce the incidence of colorectalcancer, lung cancer, and has theinhibition of tumor growth. This experimentmainly lies in the effect of EGCG on nasopharyngeal carcinoma cell line CNE2invitro conditions, changes in the expression andanalysis of STAT3signal pathwayin STAT3, CyclinD1protein, STAT3signal pathway mechanism in the process ofnasopharyngeal carcinoma, further analysis of EGCG in promoting CNE2cellapoptosis. Methods:1. Treatment of CNE2cells with24h,48h,72h by differentconcentrations of EGCG, and the cell proliferation was detected by MTT, then theproliferation inhibition rate was calculated.2. The CNE2cells treated with different concentration of EGCG were Observated by Hoechst33258fluorescencestaining, and the apoptosis rate was calculated with observation of cell apoptosis.3. The CNE2cells which were treated with different concentration of EGCG weredetected by flow cytometry to observe the influence on the cycle ofnasopharyngeal carcinoma cells.4. The expression of STAT3and Cyclin D1atdifferent time points in CNE2cells which were treated with differentconcentration of EGCG was detected by the technology of western blot.Result：1.The result of MTT showed that When improved the concentration andaction time of EGCG, the inhibitory effect of EGCG on the proliferation of CNE2cells was enhanced, with a concentration and time dependent（p<0.05）.2. TheHochest staining showed that CNE2cells which were treated with EGCGappeared typical morphological changes of apoptosis. Compared with the controlgroup, with the increase of EGCG concentration, the number of apoptotic cellswere increased（p<0.05）.3. The CNE2cells which were intervented by differentconcentrations of EGCG for24hours or48hours, were detected by flowcytometry respectively. Compared with the control group, the CNE2cellsstagnated in G1/G0were increased with the concentration increasing.4. Theexpression of STAT3and CyclinD1in CNE2cells which were intervented bydifferent concentrations of EGCG, was detected by the technology of western blot.Compared with the control group, the expression in protein quantity of STAT3andCyclin D1was decreased with the concentration increasing.Conclusion:1.. EGCG can down-regulate the STAT3protein in CNE2cells,which may be one of the biological mechanism of anti nasopharyngeal carcinoma.3. EGCG inhibited the proliferation of CNE2cells, induce its apoptosis, may beassociated with the down-regulation of Cyclin D1protein expression.