COX-2 And MMP-2 Expressions In Gastric Cancer And Its Clinical Significance

Gastric cancer is the most common tumor in human peptic malignant tumors.Most early patients have no apparent symptoms until advanced cancer which have lymphatic or distant organs metastasis.In general, the patients who have distant metastasis have poor prognosis and have a high mortality rate.Therefore, it is significant to study the mechanism of tumor metastasis by finding effective markers.Cyclooxygenase is the only rate-limiting enzyme of PG which involvs in many physical and pathology changes, such as keeping normal gastric mucosa function. COX-2 plays an important role in inflammation and tumors pathogenesis. So it can work as a target marker to prevent and treat inflammation and tumors.As we all know, tumor involvment and infiltration is dependent on destroying natural membrane, such as extracellular matrix (ECM) and basal membrane.IV type collegen which includes matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). MMP-2 plays an important role in tumor infiltration and metastasis. MMP-2 can destroy cell basal membrane and cause tumor cell to infiltrate vessel and lymph node.It is reported that COX-2 and MMP-2 is upregulated in most gastrointestinal tumors. COX-2 overexpression can induce MMP-2 overexpression and enhance its activity to make tumor metastasis.To inhibit COX-2 and MMP-2 expressions can prevent gastrointestinal tumors infiltatration and metastasis, but certain mechanism is not clear.Our research is to study the expression of cyclooxygenase-2 (COX-2) and matrix metalloproteinase-2(MMP-2)in gastric carcinoma and their relationship with tumor cell invasion and metastasis by immunohistochemistry method, and we will investigate their correlation. The expression of COX-2 and MMP-2 in 46 cases of gastric carcinoma and 15 cases of normal gastric tissue was detected by SP immunohistochemical technique. The results were analysed by SPSS 10.0. We found that COX-2 and MMP-2 were negative in 15 cases of normal gastric tissue. In 46 cases of gastric carcinoma the positive rate of COX-2 was 60.87%.It was significantly higher than that in the normal gastric tissue. COX-2 expression was correlated with lymph node metastasis and clinical stage (P<0.05). No correlation was found between increased COX-2 and the tumor size, depth of invasion and diferentiation of gastric carcinoma (P>0.05). The positive rate of MMP-2 was 71.7%. It was significantly higher than that in the normal gastric tissue too. MMP-2 expression was correlated with lymph node metastasis, clinical stage and depth of invasion (P<0.05). No correlation was found between increased MMP-2 and the tumor size and differentiation of gastric carcinoma (P>0.05). The expression of MMP-2 was significantly correlated with COX-2 (P<0.05). In summary, we conclude that the overexpression of COX-2 and MMP-2 in gastric carcinoma is closely correlation. They may play a crucial role in gastric cancer invasion and metastasis. It indicate that COX-2 and MMP-2 may be markers in evaluating prognosis of gastric carcinoma and provide targets for chemopreventive therapy.