Immunohistochemical study of Fas, Fas ligand and interleukin-1 beta converting enzyme expression in human prostatic cancer.

Abstract

To determine the cellular expression of Fas, Fas ligand and interleukin-1 beta converting enzyme (ICE) in prostatic cancer. Specimens of prostate were obtained from 21 patients (mean age 66 years, SD 5) undergoing radical prostatectomy for prostatic cancer. Nine of the 21 patients had received endocrine therapy before surgery. Specimens were also obtained from 10 patients with benign prostatic hypertrophy (BPH) and during autopsy from 10 patients who had died from hormone-unresponsive prostate cancer. Paraffin-embedded sections were cut from the specimens and stained immunohistochemically to detect Fas, Fas ligand and ICE. Fas was expressed in all 21 of the cancer specimens while Fas ligand was detected in none and ICE was expressed in 11. The difference between the expression of Fas and ICE was significant (P < 0.001). ICE was expressed in nine of 12 patients who were untreated before surgery and in two of nine treated with endocrine therapy (P < 0.05). Fas expression was detected in the specimens from all 10 patients with BPH and in all 10 autopsy specimens; the expression, tended to be more marked than that in specimens from total prostatectomy (P < 0.1). The expression of ICE was weaker than that of Fas in the total prostatectomy specimens, suggesting a possible interruption of the apoptotic signalling pathway. Prostates with BPH and hormone-unresponsive cancer therefore showed no appreciable change in Fas expression when compared with total prostatectomy samples.