EXPRESSION OF FAS AND FAS LIGAND IN TESTICULAR GERM CELL TUMORS

A molecular mechanism by which cancer cells may elude the immune surveillance involves the increased expression of the Fas ligand (FasL), able to induce apoptosis of Fas-expressing T cell infiltrates. Up to date, few and contradictory studies have investigated the expression of the Fas/FasL system in human testicular germ cell tumors (TGCT). In the present study, we analyzed the expression of FasL and its cognate receptor Fas in 13 seminomas and 6 normal testicular tissues obtained following orchiectomy. Tissue samples have been processed to prepare either total RNA or protein extracts or fixed and embedded in paraffin for IHC experiments following standard procedures. Quantitative RT-PCR experiments demonstrated in testicular cancers a significant (p<0.01) increase of the FasL mRNA expression of 21.1±5.4 fold, with respect to normal tissues. On the contrary, in the same cancer tissues the levels of Fas mRNA were significantly (p