Cyclosporin A Downregulates Fas Ligand Expression In Bladder Cancer Cell Line

Transitional cell carcinoma of bladder (BTCC) is the most common neoplasm of urological system.The incidence and death rate are the heighest in the urological system. Many studies proved the bladder carcinoma cells expressed Fas ligand to escape from immune system. To study Cyclosporin A (CsA) -mediated downregulation FasL expression in bladder cancer cell line resulting in escape from immune surveillance.BIU-87 cells and Jurket T cells were treated with CsA in different concentrations,according to the measurement results by MTT-assay ,The suitable dose of CsA was determined. FasL expression was examined by immunocytochemical technique (ICC) and flow cytomitry (FCM). Apoptosis of Jurkat T cells inducted by the Fas/FasL system was detected by FCM analysis. The results showed that in the presence of CsA(^50 u g/mL) did not result in cytotoxicity effect and anti-proliferative activity on BIU-87 cells^ 5 ?ft 50 Mand Jurkat T cells(p>0.05).The percentage of positive FasL expression and the ratio of mean fluorescence in BIU-87 cells incubated with CsA at different dose of 6.25 u g/mL, 12.5 u g/mL, 25.0 u g/mLand 50.0 H g/mL were significantly different (p<0.01).The percentage of FasL induced apoptosis of Jurkat T cells in CsA group was much lower than that in control group(p<0.01). We concluded that CsA-decreased immune escape of BIU-87 cells may contribute to downregulation FasL expression on the tumor cells and may benefit clinical treatment of bladder cancer.