| The biological characteristics of bladder cancer are complicated, include relapse, frequently-occuring, invasion and metastasis. Angiogenesis may have some important role in the occurrence and progression of the tumor. Angiogenesis is thought to depend on a precise balance of positive and negative regulation. Changes in the vasculature occur in association with many pathological processes, such as ocular neovascularization, inflammatory diseases, and cancer. Forkman reported that the growth of tumor depended on the neovascularization in 1971. So far, many reports have revealed the relationship between angiogenesis and the growth and metastasis of the tumor. The concept that solid tumor growth depends on angiogenesis is well established. Indeed, avascular tumor size is restricted to a few cubic millimeters if it is not able to attract new blood vessels.Many studies proved that a lot of cellular factors involved in the process of angiogenesis. The stimulators are vascular endothelial growthfactor( VEGF), basic fibroblast growth factor( bFGF), transforming growth factor β (TGF- β ), epidermal growth factor(EGF), platelet-derived growth factor(PDGF), angiopoietin and angiogenin, et al. The inhibitors are angiostatin, endostatin and thrombsponding-1, a factor possessing double effects.Recent work suggests that the tumor angiogenic switch is triggered by a change in the balance of stimulators to inhibitors within a given microenvironment. Therefore, the endothelial cells may secret cellular growth factors, facilitate the proliferation of tumor cell. The aim of the present study was to investigate expression of angiopoietin-2(Ang-2) in primary bladder transitional cell carcinoma and determine its relationship with both clinical and pathological factors.Objective:TO investigate expression of angiopoietin-2(Ang-2) in primary bladder transitional cell carcinoma and determine its relationship with both clinical and pathological factors.Material and Methods:43 cases of primary bladder transitional cell carcinoma and 28 cases of normal bladder tissue were collected from the department of urology of the first hospital affiliated to Z.J University and assayed by immunohistochemical staining. The findings were correlated with the clinical data from the patients.Ang-2(sc-7017), an affinity-purified goat polyclonal antibody and Streptavidin-Biotin peroxidase complex ( SP-9003 ) were all provided by Zhongshan Biotechnology Company, BeiJing.Results:Normal bladder transitional epithelial cells and vascular endothelial cells were tested negative for ang-2. Among the bladder transitional cell carcinoma there were21 cases tested positive for ang-2. Ang-2 -positive expression for bladder transitional cell carcinoma was much more apparent than for those of normal bladder tissues(P<0.01). Many tumor cells and microvascular endothelial cells show a prominent Ang-2 staining. Moreover, the vascular endothelial cells and smooth muscle cells of blood vessels and interstitial stromal cells are positive for Ang-2, whereby particularly the large blood vessels, within the tumor tissue.The rate of expression was 48.8%(21/43) and the rate of expression for ang-2 increased significantly as the pathological grading and clinical stages increased. (P <0.05).Conclusion:The angiopioetin-2 attributes to a substantial impact on biological aspects of bladder transitional cell carcinoma . Expression of Ang-2 in bladder cancer is increased much more apparent than those in normal bladder tissue. The angiopioetin-2 is thought to be involved in the neovascularization of bladder transitional cell carcinoma. It may be related to the occurrence and progression of bladder cancer. There is an important influence to a greater extent. Ang-2 could induce tumor angiogenesis and would accelerate the tumor growth. As a prognostic indicator of clinical stage and pathological grade, Ang-2 has a potential utility as a diagnostic tool for biological aspects of bladder transitional cell carcinoma.
|
PDF Full Text Request