Objective To characterize the Fas-Fas ligand system. a main apoptotic pathw
ay, in transitional cell carcinoma (TCC) of the urinary bladder, by analysi
ng the expression of Fas and Fas ligand (FasL) in TCC samples,
Materials and methods Archival paraffin-embedded tissues from 37 patients w
ith TCC were analysed by immunohistochemistry to determine Fas and FasL exp
ression.
Results Fas and FasL were detected on the cell surface and cytoplasm of res
pectively 34 (91%) and all cases analysed. The expression of Fas and FasL d
id not differ with the cytological grade of TCC.
Conclusion The high expression of FasL in TCC, reported for the first lime
in the present study, suggests that FasL may contribute to the immune escap
e of TCC through killing Fas-bearing lymphocytes. Coexpression of Fas with
FasL also suggests that TCC may hare pathways resistant to Fas-mediated aut
ocrine cell, suicide.