The Roles And Possible Mechanisms Of COX-2 In The Development Of Nasopharyngeal Carcinoma

Objective: To investigate the protein expression of COX-2 and its functions andpossible mechanisms in cell proliferation ,differentiation and metastasis of nasopharyngealcarcinoma . Methods: The immunohistochemistry was used to measure the protein expression ofCOX-2, VEGF, PCNA in 62 cases of nasopharyngeal carcinoma and poorly-differentiatednasopharyngeal carcinoma cell line HNE-1 cells. The cell growth curve was measured withMTT method, and cell cycle was measured by FCM. Results: 1. COX-2 expression was positive in nasopharyngeal carcinoma and poorly-differentiated nasopharyngeal carcinoma cell line HNE-1 cells ,but negative in normalnasopharyngeal mucosa. The positive percentage of COX-2 protein expression innasopharyngeal carcinoma tissue was 77.42%. 2. The protein expression of COX-2 was no relative with cell differentiation ofnasopharyngeal carcinoma. 3. The protein expression of COX-2 was relative with cell infiltration and metastasis ofnasopharyngeal carcinoma. The positive percentage of COX-2 protein expression was94.44% in nasopharyngeal carcinoma with lymph node metastasis and 70.45% innasopharyngeal carcinoma without lymph node metastasis. 4. The expression of COX-2 was positively relative with the expression of VEGF innasopharyngeal carcinoma tissue and the percent of co- expression of COX-2 and VEGFwas 66.13%. The expression of COX-2 and VEGF was positively relative with MVD innasopharyngeal carcinoma tissue. 5. The results of cell cycle analysis and MTT showed that celecoxib inhibited HNE-1cell growth , increased the proportion of cells in G1 phase from 62.13% to 91.35% , anddecreased the proportion of cells in G2/M and S phases from 16.28% and 21.59% to 5.10%and 3.56% respectively. 3 第三军医大学硕士学位论文 6. Celecoxib decreased the positive expression of VEGF in HNE-1 cells. Conclusions : 1. COX-2 expression was positive in nasopharyngeal carcinoma andpoorly-differentiated nasopharyngeal carcinoma cell line HNE-1 cells ,and it was possiblecorrelation with development of nasopharyngeal carcinoma . 2. The experimental results in vivo and in vitro showed that the expression of COX-2was positively relative with the cell proliferation and growth of nasopharyngeal carcinoma,and indicated that COX-2 played roles in initial development of nasopharyngeal carcinoma. 3. COX-2 enhanced infiltration and metastasis of nasopharyngeal carcinoma byenhancing the expression of VEGF in nasopharyngeal carcinoma cells and angiogenesis innasopharyngeal carcinoma tissue.