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To investigate the effect of MMP-26 on human glioma angiogenesis and the possible mechanism.Methods The MMP-26 plasmid and empty plasmid pcDNA3.1 were stably transfected into U251 cells to establish a nude mice xenograft model,and then an in vitro human tumor tissue-based three-dimensional angiagenic model.Tissue disks were visually assessed over time to determine the percentage of wells that developed an angiogenic response(I％) and the density and length of neovessel growth were graded at intervals using a semiquantitative visual growth-rating scheme (angiogenic index,AI,0-16scale) in groups of MMP-26 transfected U251 cells (U251-MMP-26),pcDNA3.1 vector-transfected U251 cells (U251-pcDNA3.1) and non-transfected U251 cells (U251).RT-PCR and immunohistochemistry were used to detect the expression of mRNA and protein of MMP-26 and VEGF in groups of U251-MMP-26,U251-pcDNA3.1 and U251.Immunohistochemical localization of CD31 was determined in the endothelial tubes invading the fibrin-thrombin clot matrix.Results Immunohistochemical endothelial cell markers CD31 was positive in the vascular tubes invading the fibrin-thrombin clot matrix,confirming their endothelial origin.The angiogenesis results showed that difference of length of micro capillaries,density of branches,and the area occupied between U251-MMP-26 groups and control groups were significant.The percentage of tumor implants that developed invasion (I％) and the angiogenic index AI in U251-MMP-26 group on day 14 were higher than those of U251-pcDNA3.1 group and U251 group (P ＜ 0.05).The trends of I％ and AI in 14 days were significant compared with those in control groups.The expression of mRNA and protein of MMP-26and VEGF in U251-MMP-26 group was significantly higher in U251-MMP-26 group than those in U251-pcDNA3.1 group and U251 group(P ＜0.01).Conclusion The effect of MMP-26 on promoting glioma angiogenesis may be related to the increased expression of VEGF,which can be used as targets for anti-tumor therapy.
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Objective To establish nude mouse model with human brain glioma SHG-44 and understand its growing characteristics in vivo.Methods The 4-week-old male mice were randomly divided into high density cell suspension inoculation group(n=10),low density cell suspension group(n=10),the tumor tissue mass vaccination group(n=10)and the blank control group with normal saline injection(n=10).The SHG-44 human brain glioma cell suspension was injected into the subcutaneous of the nude mice' s armpit.The tumor tissue was cut into 1 mm3 after tumor tissue growth and formation,and re-inoculated into the subcutaneous of the new nude mice' s armpits.Apart from daily observation,the long and short diameters of tumor were recorded every 5 days after graft.All the mice were sacrificed at 60 days and the tumor tissues were harvested for pathological examination.Results With a longer incubation period and slower growth rate,the tumor formation rate in high density cell suspension inoculation group and low density cell suspension group was lower compared with that in the tumor tissue mass vaccination group.Around day 20,grafted tumor appeared remarkably big((41.51 ±6.42)mm3) with good morphology.On day 50,the tumor derived from group the tumor tissue mass vaccination group((565.69± 123.36)mm3) showed a bigger size in comparison with that from high density cell suspension inoculation group((203.85±104.63) mm3) and low density cell suspension group ((153.02± 31.76) mm3,all P＜0.05).The tumors in three groups were well defined with a rich vascularity and no apparent invasion was observed.The positive expression of GFAP and S-100 in a large body of tumor cells was observed under optical microscope.Conclusion With a shorter incubation period and faster growth,the mouse tumor models established with tissue pieces from the tumor-bearing mice are much better compared to those with cell suspension.
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Objective To study the expression of transforming growth factor beta1(TGF-β1)and its type I receptors activin-like kinase 1(ALK1)in the human brain glioma and estimate the significance in the pathogenisis and development of human glioma . Methods The mRNA and protein expressions of TGF-β1 and ALK1 were detected with semiquantitative RT-PCR ,Western blot and Immunohistochemistry in 3 normal brain tissues and 32 patiens with human glioma .Results ALK1 and TGF-β1 mRNA and protein sometimes had co-expression in human gliomas tissues .Compared with those normal brain tissues ,the expression of TGF-β1 and ALK1 mRNA and protein in high grade gliomas were significantly increased (P<0 .05) ,the overexpression of ALK1 in human gliomas was demonstrated significant positive correlation with the pathological grades of gliomas (r=0 .297 ,P<0 .05) .Conclusion The overexpression of ALK1 may play important role in the development of human brain glioma .