The Correlation Between COX-2 And Ang-2 Expression In Human Gratric Cancer And Its Role In Lymphangiogenesis

BackgroundMetastasia is the most important characteristical of malignant turner threatening the patients'lives. Tumor cells spread in the body may be through direct invasion of surrounding tissue, blood vessels,lymphatic vessels and so on. By a large number of studies, the role of tumor angiogenesis in solid tumor growth and spread through the blood vessels has been relatively clear, inhibiting tumor angiogenesis has become a new way of clinical treatment of cancer. However, lack of lymphatic specific markers impeded the research of lymphatic metastasis.With lymphatic-specific marker D2-40,VEGFR-C, Podoplanin were successively found, in order to study the mechanism of lymphangiogenesis has laid a foundation.In recent lymphangiogenesis is recorgnized in the transfer of malignant tumor. Observations have suggested that COX-2 as an important biochemical regulators, not only inhibit tumor cell apoptosis, increased cell activity, but also increases the expression of Ang-2, thereby inducing tumor angiogenesis and promote tumor cells occurs through the blood vessels shift. The relationship between lymphangiogenesis and COX-2,Ang-2 is not reported in gastric cancer.Whether the COX-2and Ang-2 mechanism of lymphangiogenesis also play a role in gastric cancer, whether it helps lymphatic metastasis in gastric cancer still needs further study.ObjectiveTo investigate the expression of Ang-2mRNA and COX-2mRNA in gastric cancer, and measure the lymphatic vessel density in peripheral gastric cancer tissue.In this study we exporate the relationship between COX-2 and Ang-2 with lymphangiogenesis, Analysis possible mechanism of COX-2, Ang-2 in gastric cancer in the process of lymph node metastasis.Provide new ideas the clinical diagnosis and treatment of gastric cancer.Materials and methodsForty-eight excision specimens for primary gastric carcinoma were collected at Affiliated Hospital of Taishan Medical College from July 2007 to July 2009 in this study.We detected the expression of Ang-2 and COX-2mRNA by RT-PCR.In.the ex- pression of D2-40 were immunohistochemically examined in peripheral of gastric cancers and count microlym- phatic density.Then we used SPSS software to analyze their relationships and correlations with clinicopathologic findings.Results1) The positivity rate of COX-2mRNA was 85.4% in gastric cancer and signifleantly increased compared with that in normal tissue.The expressin of COX-2 was positively correlated with clinical stage lymph node metastasis.2) The expressin of Ang-2 mRNA was 65% in gastric cancer and signifleantly increased compared with that in normal tissue.The expressin of Ang-2 was associated with lymph node metastasis, clinical grade.3) A significant correlation was found between the expression of Ang-2 and COX-2.4) MLVD was associated with lymph node metastasis, clinical grade and the expression of Ang-2 and COX-2Conclusions1) The over-exoression of COX-2 mRNA and Ang-2 mRNA were found in gastric carcinoma.The COX-2 and Ang-2 generation increased probably may play an important role in the occurrence and development of gastric cancer.2) MLVD was associated with lymph node metastasis and clinical grade. Lymphangio-genesis helps lymphatic metastasis in gastric cancer.3) COX-2 expression was positively correlated with Ang-2,and both of them correlate with MLVD,the presence of lymphatic invasion and TNM stage. COX-2-mediated Ang-2 overexpression might promote lymphaticinvasion via lymphangiogenesis pathway in patients with gastric cancer.