Expression And Relationship Between Cyclooxygenase-2 And Latent Membrane Protein-1 In Nasopharygeal Carcinoma

Background and Objective:Nasopharyngeal carcinoma(NPC)is the most common one of malignant tumor in head and neck.According to WHO statistics,80%of them happened in China.Nasopharyngeal carcinoma is characterized with infiltrating and metastasis.60%NPC patients have been founded with neck lymphatic metastasis at their first examination.98%NPC is poorly differentiated squamous cell carcinoma.Studies have demonstrated that cyclooxygenase-2(COX-2)is the rate-limiting enzyme prostaglandin, concerned with prostagland in synthetical and played an essential role in many tumors' genesis,growth and lymph nodes metastasis.Studies have demonstrated the relationship between NPC and Epstein-Barr vitus(EBV) infection.Epstein-Barr vitus latent membrane protein-1(LMP1)is the primary carcinogen with multiple biological functions.Previous studies had demonstrated that NPC can express COX-2,LMP1 highly,but their association were not very clearly.In our experiment,the expressions of COX-2 and LMP1 were immunohistochemically studied in 53 NPC sections,we wanted to know the correlation between COX-2,LMP1 in NPC.Materials and Methods:53 nasopharynx biopsy specimens from patients with NPC who had been diagnosed definitely by pathology from Sir Run Run Shaw Hospital,Medical School of Zhejiang University from 2000 to 2005.The specimens included 24 male and 29 female patients(age ranged from 18 to 81 years old,mean age was 52 years old).Neck lymph nodes metastasis in these patients was 38 cases,and none neck lymph nodes metastasis was 15 ones. Pathological classification:Keratinizing squamous cell carcinoma was 4 cases,nonkeratinizing squamous cell carcinoma 27,and undifferentiated carcinoma 22.Accordong to 1997 UICC classification,T₁ was 14 cases,T₂ 14 cases,T₃ 14 cases and T₄ 11 cases;N₀ was 15 cases,N₁ 22 cases,N₂ 11 cases and N₃ 5 cases;Stageâ… was 5cases,â…¡14 cases,â…¢19 cases andâ…£15 cases. 8 nasopharyngeal biopsy specimens were collected from patients with chronic nasopharyngeal who had been diagnosed definitely by HE stain in the same hospital(male 5 and female 3),which were served as normal controls.All these tissue samples were fixed in 10%formaJdehyde solution after being obtained, then embedded in paraffin,5-micrometer thick sections were prepared for examining the expression of COX-2,LMP1 by streptavidin-peroxidase immunochemistry.All the datas were analyzed statistically with SPSS 12.0 software in computer.Result:1.In Nasopharyngeal carcinoma tissue,Positive expression rate of COX-2 was 71.70%(38/53);Positive expression rate of LMP1 was 66.04%(35/53)。2.In Nasopharyngeal carcinoma tissue,there was significant relation of COX-2,LMP1 with N stage(P＜0.05), none-significant ralation of COX-2,LMP1 with age,ender, tumor stage,clinical stage and pathological classification(P＞0.05).3.In Nasopharyngeal carcinoma tissue,the expression of COX-2 showed a significant positive correlation with the expression of LMP1(r=0.797,P＜0.001)。Conclusion:1.The results suggested that COX-2,LMP1 were highly expressed in nasopharyngeal carcinoma cells.2.The expressions of COX-2,LMP1 were significantly associated with neck lymph nodes metastasis. none-significant ralation of COX-2,LMP1 with age,gender,tumor stage,clinical stage and pathological classification.3.The expression of LMP1 showed a significant positive correlation with the expression of COX-2,and it showed that LMP1 could enhance NPC metastasis by up-regulating the expression of COX-2.