Role of apoptosis stimulus factor and its ligand in the induction of apoptosis in some ultraviolet induced diseases

BACKGROUND: Fas (factor of apoptosis stimulus) is one of the death receptors belonging to the tumor necrosis factor superfamily of receptors. When bound to its ligand, Fas-ligand (Fas-L), it triggers apoptosis. Ultraviolet (UV) rays can induce keratinocyte apoptosis by Fas/Fas-L interaction. AIM: The aim of the study was to evaluate the role of Fas and Fas-L in basal cell carcinoma (BCC) as an example of malignant neoplasm and discoid lupus erythematosus (DLE) as a benign skin disease, which are both induced by UV. SUBJECTS AND METHODS: The study included 20 cases of BCC, 20 cases of DLE and ten control cases. All biopsies of BCC and DLE were examined histopathologically. They were also examined for Fas and Fas-L by PCR. RESULTS: In BCC, apoptosis was detected in 60 percent of cases. Fas was found to be positive in only one case and it was found to be negative in the other 19 cases (95 %). Fas-L was found to be positive in 100 percent of cases. In DLE, apoptosis was detected in 90 percent of cases. Fas was positive in 80 percent of cases, Fas-L was positive in 90% of cases. CONCLUSION: Over-expression of Fas-L and lack of expression of Fas by tumor cells together with other factors act in favor of BCC by helping its survival and progression. Also, it seems that Fas/Fas-L interaction plays a critical role in the apoptosis seen in cases of DLE and hence in the pathogenesis of DLE.