Effect of matrix metalloproteinase-26 on human glioma angiogenesis / 临床与实验病理学杂志

ABSTRACT

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.