| Astrocytoma is the commonest primary tumor of brain; it greatly endangers human life, leading to poor prognosis. The tumor has some specific biological characteristics. It grows invasively, especially locally without forming capsule.Clinical and animal experiments have shown that without newly growed blood vessels providing nutrition, the tumor grows after it has reached a diameter of 1 - 2mm. So the angiogenesis ability is one of the crucial factors for tumor growth, invasion and metastasis. The new capillaries provide nutrition to the tumor as well as facilitate its invasion and metastasis. So it has become a crucial point to find ways to suppress the growth of new blood vessels.β - catenin plays important roles in WNT signal transduction pathway of the cell. It is involved in both signal transduction and cell adhesion. β - catenin enters the cell nuclear and acts as a transduction factor, leading to the expression of the cell proliferation related genes then cells begin to proliferate.β - catenin binds witha - catenin and actin. In endothecytes, it acts as adhesion molecule, which coop-crates with VE -cdherin, CD31 and F -actin, induce angiogenesis.Materials and methods1. material 48 samples of astricytoma were obtained from patients by surgical operations. (Including 8 benign astrocytomas ( BA) , 25 anaplastic astrocytomas ( AA) , 15 glioblastorm multiform ( GBM ) , 10 normal brain tissues ( NB) were obtained from internal decompression operations as controls.2. agents (1) instant - type rat - human |3 - catenin monoclonal antibody from Maixin company in Fujian (clonal code: CAT-5H10, No: MAB -0259). (2)0.05% DAB from the same company (colonial code : CAT No: DAB -0031/1031)3. methods the tumor tissue and vascular cells from the 48 astrocytomas ( AC) of various grade were all tested of their level andp -catenin , using the hypersensitive S - P method. The vascular cells were identified by PAS staining. Normal brain tissues were used as positive controls, while negative controls were obtained by using PBS instead of the primary antibody.ResultsIn the normal brain vessels, β - catenin was basically expressed at vascular cell - cell junctions and the internal surface of the vascular lumen, with the color of the brown. All the expressions were normal and no heterorganic expressions were found. In contract, VC ( vascular cell) was homogeneously stained in the cytoplasm in one case of 8 BAs, in 17 of 25 AA, in all of 15 GBM, and overall in 33 out of the48 ACs. Furthermore, nuclear staining was recognized in one case of BAs, 8 of 25 AAs, 8 of 15 GBM and 17 of all tumors. No staining of cells was found in the 8 BA, but in 13 of 25 AA and 14 of 15 GBM, staining of tumor cells was obtained.Another method followed was that of Jawhari, who divided the cells according to whether or not only they heterogenic expression ofβ - catenin was one of 8 BA. 17of 25 AA and all of the 15 GBM have abnormal expressions.In PAS staining, the vascular membrane was stained with the color of pink. The microvessel density was counted, significance between GBM, AA and BA, NB.DiscussionFolkman asserted that angiogenesis plays an important role in the development of malignant brain tumors. It provides nutrition and maintains the metabolism of the tumor. The tumor cannot develop, invade or metastasis without the formation of microvasculature. So it may have great clinical significance to develop a treatment aimed at blocking angiogenesis.Some researchers have reported about the vasogenetic factors produced by the tumor cells themselves and the inflammatory cells surrounding or in the tumor. But recently few researchers have got been made about the role adhesion molecules taking in vasogenesis. Though the mechanisms have not been fully understood yet, some definite proofs have shown that the adhesion molecules on the surface of tumor cells can induce gamogenesis through the interactions between endo-thelicocytes and extra cellular substances.β -catenin is a 92Kda...
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