Significance Of DcR3,PTEN And PCNA In Gastric Cancer

IntroductionGastric cancer is the most common in alimentary tract malignant tumors.It lies in the second place of malignant tumor deadly reason.Gastric cancer is the disease of multiple gene and closely related to more than one hundred genes.About 60%patients died because of recurrence and metastasis though they all received effective therapy. Many studies show that the occurrence of cancer is the process of cell over-proliferation and reduced apoptosis.Decoy receptor 3(DcR3) is a new member of tumor necrosis factor receptors which were found recently.It can specifically bind some protein ligands and competively inhibit the binding of ligands and dead receptors. So DcR3 can stop the ligands inducing apoptosis.Tumor suppressor gene phosphatase and tensin homolog deleted on chromosome ten(PTEN) has dual specificity phosphatase activity.It can lead to arresting in G phase of cell cycle and apoptosis,and inhibit tumor invasion and metastasis by many ways.The degradation of extracellular matrix and basement membrane is the key progress of tumor invasion and metastasis. Proliferating cell nuclear antigen(PCNA) is an accessory proteins of DNA polymerase. It is related to S phase proliferation of cell cycle.PCNA can be an index of evaluating cell proliferating status and it is important in cell cycle.We used immunohistochemical method to study the expression of DcR3,PTEN and PCNA in gastric cancer and approach their function in gastric cancer occurrence, development,invasion and metastasis.So we can provide new evidence in tumor prophylaxis,clinical diagnosis and clinical therapy.ObjectivesThe purpose is to approach the expression of DcR3,PTEN and PCNA in gastric cancer and the ralationship to gastric cancer biological behaviour.We studied the influence of DcR3,PTEN and PCNA to gastric cancer cell invasion and proliferation. We also studied the role of DcR3,PTEN and PCNA in tumor occurrence,apoptosis and proliferation.So we can use to gastric cancer prophylaxis and clinical therapy.Methods1.Patients and tissue collection54 cases of gastric carcinomas were collected after surgical resection performed in Shengjing Hospital during 2001-2003.None of the patients received chemical therapy or radiotherapy before resection.Another 15 samples from normal gastric tissue were as the control group.2.The agentsMouse anti-human DcR3 monoclonal antibody were bought from NEOMAEKWES Company(working concentration 1:75),mouse anti-human PTEN monocloncal antibody and mouse anti-human PCNA monoclonal antibody were bought Zhongshan Biological Technical Company in Beijing.The working concentration of PCNA was 1:100,PTEN was 1:100.Supersensitivity SP kits and DAB reagents were all purchased from Maixin Corporation(Fuzhou,Fujian province,China).3.MethodWe put paraffin block HE dyeing and definite the degree of histodefferentiation. We detected the expression of DcR3,PTEN and PCNA in gastric cancer and normal stomach tissue by SP immunohistochemical methods.The positive cell of DcR3 was seen in cytoplasm and showed brown particles.PTEN was in cytoplasm and brown paritcles.PCNA was in cell nucleus and also brown particles.All results were expressed as mean±SD.Statistic software SPSS 13.0 for Windows was used to analyze the results using Student t test and Pearson correlation analysis.The accepted level of significance was P＜0.05(Two-tailed).Results1.The expression rate of DcR3 in gastric cancer is 42.6%and it is positive correlation with lymphatic metastasis,clinical stage,invasion depth,distant metastasis and the size of tumor in gastric cancer(P＜0.05).It is negative correlation with the degree of pathological differentiation(P＜0.05).2.The expression rate of PTEN in gastric cancer is 50.0%and it is negetive correlation with lymphatic and distant metastasis,invasion depth and clinical stage(P＜0.05).It is positive correlation with the degree of pathological differentiation(P＜ 0.05).3.The expression rate of PCNA in gastric cancer is 51.9%and it is positive correlation with lymphatic metastasis,clinical stage,invasion depth,distant metastasis and the size of tumor in gastric cancer(P＜0.05).It is negative correlation with the degree of pathological differentiation(P＜0.05).4.DcR3 and PCNA are of positve correlation(r=0.755,P＜0.001).DcR3 and PTEN are of negative correlation(r=-0.487,P＜0.001).PCNA and PTEN are of negative correlation(r=-0.371,P＜0.001).Conclusions1.The positive rate of DcR3,PTEN and PCNA is closely related to lymphatic and distant metastasis,invasion depth,clinical stage and pathological differentiation degree in gastric cancer.So we can conclude that they all have important role in gastric cancer occurrence,development,invasion and metastasis.2.DcR3 and PTEN are of positive correlation,so we can conclude that they are co-restricted in gastric cancer occurrence,development,invasion and metastasis.3.DcR3 and PCNA are of positive correlation,so we can conclude that they are co-facilitative in gastric cancer occurrence,development,invasion and metastasis.4.PTEN and PCNA are of negative correlation,so we can conclude that they are co-restricted in gastric cancer occurrence,development,invasion and metastasis.5.Every one of them DcR3,PTEN and PCNA can become the important index of gastric cancer diagnosis and prognosis.