| Angiogenesis is considered as one of the important manifestations of tumor occurrence. Datas confirm that as an significant factor of tumor ecosystem, angiogenesis involves and affects its biological behavior. Erythropoietin(Epo) is an essential stimulator of erythropoiesis.Erythropoiesis was considered to be the sole physiological acton of EDO. However, many malignant tumors originated from non-haematopoietic organs and tissues express EPO and EPO-R. And It has been shown to modulate host cellular signal transduction pathway to perform many other functions, including promotion of angiogenesis, prevention of cellular apoptosis, and protection against the effects of hypoxia. And which suggests that EPO is involved inthe development of these malignant tumors and may be a factor endogenously stimulating angiogenesis. This study aims to find out the relationship between erythropoietin/erythropoietin receptor and human gastric carcinoma and the clinical significance.Objective: To detect the expression of erythropoietin receptor (EPO-R) and the microvessel density(MVD) of gastric carcinoma. To investigate the relationship between the expression of Epo-R and tumor angiogenesis and biologic behavior in gastric carcinoma, and analyze their significances hi clinical research; To establish an implanted model of human gastric carcinoma on chick embryo. And recombinant human erythropoietin was given, its effects on angiogenesis and tumor growth were examined. And analyze the action mechanism.Method: Experiment 1: Expression of EPO-R and MVD of 50 specimens resected from patients with primary gastric adenocarcinoma were investigated by imrnunohistochernical methods using antibody to EPO-R and CD31. And analyze the relationship between expression of Erythropoietin receptor and biology characteristics of gastric carcinomaExperiment 2: The human gastric carcinoma cell line SGC-7901 was transplanted on the chick embryo's chorioailantoic membrane(CAM). And then recombinant human erythropoietin was given on the implanted tumor asthe disposed group. And PBS was given to the control group. Through the application of microphotographics and image analyzing system, general observation under stereomicroscope, counting vessels of the spreading CAM in situ, weighing the implanted tumors and examining their histology. Analyzing the effect of recombinant human erythropoietin on angiogenesis and tumor growth, as well the action mechanism.Results: Experiment 1: In gastric adenocamoma, the level of MVD was significantly increased, campared with that in the normal tissues (25.17 13.02 vs 11.61 4.40,P<0.01) . Morever, the level of MVD seemed to be closely related with the tumor size, invasive depth, lymph node metastasis, distant metastasis and the p-TNM stage, but not with the extent of differentiation. MVD was dosely related with the expression of the EPO-R(P<0.001). The expression of EPO-R increased with the increasing of MVD. Satge IV gastric carcinoma has a higher degree of vascularization than other stages. EPO-R level in tumor cells highly correlates with the extent of angiogenesis and progression of patients with gastric carcinoma.Experiment 2: We have successfully established the implanted model of human gastric carcinoma on chick embryo. The biology characteristics of the implanted tumor was similar to that of human gastric carcinoma; The recombinant human erythropoietin can promote significantly angiogenesisand tumor growth of the implanted tumor. The number of the newly formed vessels upon the tumor was significantly increased in the group using the recombinant human erythropoietin as compared with the PBS control group. The counting vessels were 40.10 2.11 vs 30.85 1.93 in disposed group and control group respectively(P<0.01).The weight of the implanted tumor of disposed group and control group were 0.1048 0.0055g and 0.0727 0.0058g respectively, and the weight of disposed group was significantly greater than that of control group (P<0.01). Optical microscopy showed the increase in the tumor cells population and the...
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