Expression Of MMP-7, E-cadherin, And VEGF And Relation-ship With Biological Behavior Of Gastric Cardia Cancers

IntroductionThe epidemiology of proximal ( cardia and gastroesophageal junction) and distal (antrum and corpus) gastric carcinomas is strikingly different despite similar morphologies. Carcinoma of the distal stomach is decreasing in incidence, whereas proximal carcinomas are increasing in incidence more than any other cancer in the Western world. Gastric cardia carcinoma is a kind of gastric cancer that the center of tumor localized in the part range from the dentate line to two centimeters below it. This phenomenon has so far not been satisfactorily explained. Gastric carcinoma carries a grave prognosis.Two major characteristics of malignant tumor cells are invasion and metastasis , for which proteolytic degradation of the extracellular matrix, including basement membrane, by matrix metalloproteinases ( MMPs ) is one of the essential e-vents. MMP -7, one of the MMPs family members, has a broad spectrum of proteolytic activity against a variety of extracellular matrix substrates, including type Ⅳ collagens, proteog - lycans, laminin, fibronectin and casein. It can also inactivate α1 - anlitrypsin, which augments the serine protease activity, resulting in activation of MMPs themselves. MMP-7 is expressed predominantly by tumor cells in various cancers. E - cadherin is a calcium - dependent cell - cell adhesion molecule which, together with the catenins interacting with its cytoplas-mic tail, forms a powerful invasion suppressor complex. E - cadherin is a cell -cell adhesion molecule having invasion suppressor activities. Disturbance of the E - cadherin/catenin complex during tumor progression is correlated with the on-set of an invasive phenotype . VEGF is a kind of angiogenesis factor which can specific combine with Angioendothelial cell, promote endothelial cell growth. And it has vessel permeability which can assist tumor cell to enter vessel system. Angiogenic activity of VEGF, which is probably inhibited by VEGF - CTGF complex formation in normal articular cartilage, may be reactivated by CTGF degradation with MMPs overproduced. The metalloproteinases matrilysin cleave E - cadherin at the cell surface and release sE - CAD into the medium. The soluble Ecadherin fragment thus released inhibits E - cadherin functions in a parac-rine way. Recent studies have demonstrated that Ang -2 mRNA levels were increased by VEGF or hypoxia in bovine microvascular ECs , and Ang - 2 up -regulat expression.Study has showed that MMP - 7, E - cadherin and VEGF were correlated with occurring of gastric cancer. MMP - 7 and VEGF were highly expressed in gastric cancer and less or absently expressed in normal gastric tissue, which correlated with tumor invasion, metastasis and prognosis. Whereas, E - cadherin was completely expressed in normal gastric tissue and significantly less expressed in gastric cancer which correlated with tumor invasion, metastasis and prognosis.Expression of E — cadherin in cardia caicinoma have been reported, wheras there were no report about expression of MMP - 7 and VEGF.ObjectiveThe aims of this study were ( 1) to compare protein expression of Matrix Metalloproleinases - 7, E - cadherin, and Vascular Endothelial Growth Factor between cardia and antrum gastric adenocarcinomas and (2 ) to investigate relationship between the expression and biological behavior of bastric cardia cancers.Methods1. Clinical materialsTumor group: Paraffin embedded tumor specimens were obtained from 41 patients(33 men,8 women, the age ranges from 28 to 78(50. 2 in average)) who underwent surgery for gastric cardia carcinoma and 45 patients (24 men , 21 women, the age ranges from 38 to 80(56.6 in average) ) who underwent operation for gastric antum carcinoma in Department of Oncology, the First Affiliated Hospital of China Medical University from 1998. 9 to 1999. 12. All the patients did not accept any treatment before. Normal control group: 10 cases (5cardia, 5antum) of normal gastric mucosa tissue were obtained from the biopsies.2. Main ReagentsMouse Anti - MMP - 7 Monoclonal Antibody were brought from Fuzhou Maixin - Biological Technology Ltd .Mouse Anti - E - cadherin Monoclonal Antibody were brought from Santa Cruz Biotechnology,Inc.Rabbit Anti - VEGF Polyclonal Antibody were brought from Wuhan Boster - Biological Technology Ltd .SP Immunohistochemistry Kit and DAB chromogen were brought from Fuzhou Maixin - Biological Company.3. MethodsAll the samples were sliced up serially with thickness of 4jxm. Immunohistochemistry S - P methods and HE staining were performed. Purchased positive control picture is used as positive control, and PBS solution replacing first antibody as negative control. MMP -7,VEGF is expressed in cells of gastric cancer mucosa with brown - stained plasma. E - cadherin is expressed in all cells of normal gastric mucosa with uniform brown - stained membranes and plasma, positive is defined as more than 10% positive cells. Normal expression of E -cad in tumor tissue is defined as the same expression way and intensity as normal tissue. While abnormal expression is defined as less than 90% positive cells.4. Analysis statisticsThe statistical analysis was assessed by SPSS 10.0 sofeware. x2 ~test was used for frequence comparison. P <0. 05 has significance of defference.Results1. The results of clinical pathologyThere was no significant difference between gastric cardia carcinoma and pyloric carcinoma in size of tumor, pathological type , macroscopic type, T Classification of tumors, TNM stage and growth pattern. But there was significant difference in lymph node metastasis between them.2. Expression of MMP - 7, E - cadherin and VEGF in cardia carcinoma and pyloric carcinomaE - cadherin was completely expressed in normal gastric mucosa. MMP - 7 and VEGF were mainly expressed in cytoplasm of gastric cancer cell, less or absently expressed in normal mucosa and absently expressed in stroma. The positive rates of MMP -7 were 75. 6% in cardia carcinoma and 53. 3% in pyloric carcinoma, there was significant difference between them. Expression of E -cadherin in cardia carcinoma reduced to 30. 0% and in pyloric carcinoma reduced to 31. 1% , there was no significant difference between them.3. Paired comparison of expression of E - cadherin, VEGF and MMP - 7 MMP -7 and E -cadherin both positive were 15 cases, MMP -7 positiveand E - cadherin negtive were 40 cases, MMP - 7 negtive and E - cadherin positive 15 cases, MMP -7 and E - cadherin both negative were 16 cases. There was significant difference between them. Otherwise, there was no significant difference between MMP-7and VEGF.4. Relationship between expressions of MMP -7, E - cadherin, VEGF and biological behavior of cardia carcinoma1 )The expression of MMP -7 was not related to size of tumor,pathological type, macroscopic type and growth pattern, but related to T Classification of tumors, lymph node metastasis and TNM stage. 2) The expression of E -cadherin was not related to size of tumor, pathological type and macroscopic type, but related to T Classification of tumors, lymph node metastasis ,TNM stage and growth pattern. 3) The expression of VEGF was not related to size of tumor, pathological type and macroscopic type, but related to T Classification of...