Correlation between soluble Fas level and apoptosis of T cells in ovarian carcinoma

Abstract

Objectives The objectives were to examine the correlation between soluble Fas (sFas) level and apoptosis of T cells in peripheral blood and peritoneal fluid of patients with ovarian carcinoma and to investigate the possible sFas effect on T cell apoptosis. Study design Patients with stages I–II ovarian carcinoma ( n = 10) and patients with stages III–IV ovarian carcinoma ( n = 22), as well as ovarian benign tumors ( n = 8), were enrolled in the study. Apoptosis of and Fas expression on T cells from peripheral blood and peritoneal fluids were assessed by flow cytometry. Soluble Fas level was assayed using an ELISA kit. The effects of peritoneal fluid on Jurkat cell apoptosis with or without depletion of sFas were evaluated and compared in vitro. Results The sFas level and apoptosis of T cells in peripheral blood and peritoneal fluid from stages III–IV ovarian carcinoma were significantly higher than those from stages I–II ovarian carcinoma ( p < 0.01 in all instances) and benign ovarian tumor ( p < 0.01 in all instances). In peritoneal fluid, the sFas level and apoptosis of T cells from stages I–II ovarian carcinoma were significantly higher than those from benign ovarian tumor ( p < 0.01 in all instances), and the Fas expression on T cells from ovarian carcinoma were higher than those from benign ovarian tumor ( p < 0.05 in all instances). There was a positive correlation between the sFas level and the apoptosis of T cells in peritoneal fluids from stages III–IV ovarian carcinoma ( r = 0.647, p = 0.001). Peritoneal fluid of ovarian carcinoma could induce significant Jurkat cell apoptosis. The blocking of Fas expression on the Jurkat cell surface, but not the deletion of sFas, may remarkably restrain the apoptosis level. Conclusions Elevated sFas is correlated with apoptosis of T cells in peripheral blood and peritoneal fluid from ovarian carcinoma. Soluble Fas evidently does not affect T cell apoptosis, which is probably due to elevated Fas expression on T cells.