| ObjectiveFas,as an signal receptor of cell apptosis discovered in recent years ,can send apoptosis message to and induce the dying of the cell to which the Fas belong to. The sensitivity of tumor cells to Fas/FsaL apoptosis-intevention system is decided by many factors, involving many control mechanisms. It is a important factor for apoptosis that the cell surface represents factional Fas molecule and oncentration of it reaches certain level.A majority of tumor cells represent FasL in a higher level, which may connect with Fas positive and activated T cells and induce the apoptosis of T cells, and it may be ascribed to one of the mechanisms of tumor immune escape. Glioma, which is the most common intracranial tumor, represents high FasL level. Our initial investigation using duplicate immunocytochemistry illustrated: The high FasL located at microvascular endothelial cells consisting of the glioma rather than the tumor cells themselves. By culturing human brain microvascular endothelial cells and glioma cells separatedly and simutaneously ,and then analyzing their pre- and post-cultune FasL levels, we study the effect of the grouth of glioma cells upon FasL level of human brain microvascular endothelial cells.MethodsHuman brain microvascular endothelial cells and glioma cells, U87 and U107, were cultured. After generations, human brain microvascular endothelial cells and glioma cells were cultured separatedly and simutaneously. Western Blot was used to investicate the pre-and post-culture FasL levels of human brain microvascular endothelial cells and glioma cells which those cultuned simutaneously. Western Blot results were scanned by Chemi Imaer 5500 V2. 0 , and a quantitive analysis was dealt with Fluor Chen 2.0 software. All data were statis-tically analysed by SPSS11.0 statistic analysis software system, The results were shown in average and standard deviation and the statistical method is the independent-sample t test, p < 0.05 which statistical significance.ResultFasL representation tested by Western Blot : there is a difference of as representation between human brain microvascular endothelial cells and glioma cells pre-and post-culturing simultaneously. When comparing the Integrated Density Value,IDV,of FasL representation levels, EC cultured alne( 19381. 76 4366. 27) vs EC co-cultured with U87 cells(47256. 15 5387. 28) (p <0.05); EC cultured alne( 19381.76 4366.27) vs EC co-cultured with U107 ceUs(52156. 36 7927. 53) (P < 0. 05); U87 cells alone ( 20764. 34 4857. 96) vs U87 ceUs with EC(26358.25 6168.72) (P >0. 05); U107 ceUs alone(23957. 83 4932.16) vsU107 cells with EC(27365. 13 6396. 76) (P >0. 05), all of which demonstrated that there is a significant difference between pre- and post co-culltured human brain microvascular endothelial cells.ConclusionAfter analyzing Fas and FasL representation of 22 human glioma, Husain tested Fas and FasL positive 13 cases and 15 cases seperatedlly by Western blotting and immuriocytochemical method, and demonstrated 4 cases representing Fas and FasL simultaneously in 7 glioma cell families by the same method. Husain also continued to study the FasL representation in human rectal cancer and metastatie in liver, and they found 2 FasL positive cases out of 7 primary cancers , meanwhile, all of 4 cases with liver metastasis representing positive FasL. These findings suggest that the metastasis and growth after metastasis happen easier in FasL positive cells, and the reason may be ascribed to the fact that FsaL negative cells will be easily attacked by activated T cells, in comparison, FasL positive tumor cells escaping fom the attack, inducing the apoptosis of the local liver cells, Fas positive, and contributing greatly to formation of place of planta-tion. It is suspected that FasL representation is one of the most important mechanisms for tumor cells escaping from immune reaction during the course of grouth and metastasis.As a conclusion, our experiment shows a significant increase of FasL level in microvascular endothelial cells a...
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