Expression Of HGF And UPA In Gliomas Of Different Pathological Grades: A Study Of The Correlation

ObjectiveThe growth of tumors involves many procedures including proliferation of tumor cells, hydrolysis of extracelluar matrix and formation of tumor vessels..Studies show that HGF plays important roles in genesis and development of malignant tumors. (1) HGF is a powerful mitogen. It stimulates the growth of tumor cells. (2) HGF induces tyrosirie phosphorylation of local molecules and helps to activate integrin. As a result, it facilitates the adhesion, movement and aggression of carcinoma cells. (3) HGF upregulates the expression of molecules concerned with hydrolysis of extracellular matrix, such as uPA and its receptor. (4) HGF promotes growth of vascular endothelial cells and upregulates VEGF, hence the tumor angiogenesis to supply the tumors and carry away the waste. Plasminogen, when activated by uPA, turns into plasmin, which helps to degrade extacellular matrix, causing the spread of tumor cells to the corresponding region.Studies in these years have documented that HGF and uPA correlate with each other and there is an HGF-met-uPA plasmin pathway in malignant tumors, which may play an important role in its invasion and metastasis.Human brain gliomas are the most common malignant tumors of central nervous system. The relationship between gliomas and HGF and uPA is not clear at present. So we examine the expression of HGF and uPA in human glioma cells in order to preliminarily evaluate the possible correlation between them. This may provide a new thought for futher study of gliomas.MethodsIn our study, the expression of HGF and uPA is measured by immunohisto-chemistry method. 62 paraffin-embeded glioma tissues and 8 normal brain tissues are collected for this investigation. Immunohistochemical staining was performed according to the instructions provided by the manufacturer.Result determining; cells which show brownish cytoplasmic staining are considered as HGF or uPA positive. The ratio of positive cells is calculated in 5 randomly selected visual fields each slide.Statistical analysis: Wilcoxon Mann-Whitney test was used to determine the expression in different grades of gliomas for significant differences. The difference between gliomas and normal brain tissues was examined by x2test.ResultsHGF is expressed in cytoplasm of glioma cells. No expression was found in normal brain tissues. uPA is expressed in cytoplasm of both glioma cells and vascular endothelial cells. Both HGF and uPA in gliomas increase in parallel with the grade of gliomas. There is significant difference between low-grade gliomas and high-grade gliomas ( P < 0. 05 ) .ConclusionThis study indicates that HGF and uPA may play a significant role in the development and invasion of glioma cells.