PROBLEM: Decay accelerating factor (DAF) is implicated in protection of cell membrane from toxicity of complement. In this study, we investigated a hypothesis that DAF is up-regulated in the endometrial adenocarcinoma, which could increase potential of malignant cells to escape destruction by complement.
METHODS: DAF density was evaluated in endometrial biopsies of patients with adenocarcinoma at various stages and compared with ten endometrial biopsies from non-malignant patients at the proliferative phase.
RESULTS: DAF expression in normal proliferative endometrium varied between 1 and 30%. While DAF density in patients with stage I cancer was in the range 56–98% (mean 78%), stage III values varied from 28 to 16% (mean 21%), P<0.05. DAF density in the well-differentiated Ishikawa cell line was two-fold higher than in metastatic cell line AN3CA.
CONCLUSIONS: Our findings are consistent with a hypothesis that endometrial adenocarcinoma of early stage that is exposed to complement attack may up-regulate DAF to protect malignant cells from complement lysis.