Increased Fas ligand expression in the tumor tissue and serum of patients with testicular germ cell tumors with seminomatous elements

Objectives. To measure the expression levels of Fas and Fas ligand (FasL) i n testicular germ cell tumor (TGCT) and to determine whether the serum leve l of soluble FasL (sFasL) could be-used as a marker for patients with TGCT. Methods. The expression of Fas and FasL in 51 specimens obtained from patie nts with TGCT was examined by reverse transcriptase-polymerase chain reacti on, and the results were confirmed by Western blot analysis. The serum leve ls of sFasL in 24 patients with TGCT were measured using an enzyme-linked i mmunosorbent assay system. Results. Of 33 TGCT specimens that included seminomatous elements, Fas and FasL was expressed in 24 (73%) and 24 (73%), respectively. On the other han d, 10 (56%) and 2 (11%) specimens expressed Fas and FasL, respectively, in 18 TGCT specimens without seminomatous elements. Moreover, the serum levels of sFasL were significantly higher in patients with TGCT with a seminomato us element than in those without it. Conclusions. These results indicate that FasL is strongly expressed in tumo r tissue and is present at high levels in the serum of patients with TGCT w ith a seminomatous element compared with those without it and that the seru m levels of sFasL could be used as a novel diagnostic marker for TGCT with seminomatous elements. UROLOGY 58: 471-476, 2001. (C) 2001, Elsevier Scienc e Inc.