The FAS-related apoptosis signaling pathway in the prostate intraepithelial neoplasia and cancer lesions.

An aim of the study was to determine the protein expression of the FAS-related apoptosis signaling pathway (FADD-FAS Associating Protein with Death Domain, PRO-CASPASE-8 and CASPASE-8), which are responsible for signal transduction to trigger programmed cell death (apoptosis) in cancer and Prostatic Intraepitelial Neoplasia (PIN). 20 specimens from prostate cancer patients treated with radical prostatectomy were inwestigated. 8 cancers were diagnosed as G-2 and 12 as G-3. 14 samples were described as poorly differentiated, high Gleason score (> or = 7). Control group consisted of prostate specimens from autopsy of 3 young men. Specimens were fixed in 10% buffered formaldehyde and immersed in paraffin. Haematoxylin and eosin staining was done. Monoclonal antibodies to FADD & CASPASE-8 (Novocastra, UK) were used to immunohistochemical study, according to streptavidine-biotin method. Semiquantitive method described protein expression. Expression index (EI) was calculated as a percent of positive FADD or CASPASE-8 cells to total cells in the specimen. Statistical analysis was performed with the Student t-test (p < 0.05). Normal prostate tissue was negative in both, FADD and CASPASE-8 immunohistochemistry staining. PIN & prostate cancer lesions were found to strongly express of FADD & CASPASE-8 proteins. Expression of FADD in cancer lesions was 66,5+/-27,8% and 59,8+/-19,0% vs. 56,8114,8% HGPIN and LGPIN, respectively. Expression of CASPASE-8 in cancer lesions was 64,1 + 23,4% and 61,5+/-15,0% vs. 48,0+/-17,6% HGPIN and LGPIN, respectively. PIN & prostate cancer lesions are characterized by similar high expression of proteins responsible for signal transduction to induce apoptosis. The mediators of apoptotic signal can be very important in prostate cancer prophylaxis and management.