Fas antigen and Fas ligand with Oral Disease

为了确定Fas抗原与口腔上皮细胞凋亡的关系，我们采用免疫组织化学和免疫印迹法研究了Fas抗原在口腔黏膜中的表达。Fas抗原分布于正常人牙龈棘层和角质层基底。估计Fas抗原的分子量为35000，这与Fas抗原的报道值一致。Fas抗原的表达与肿瘤分化程度有关。采用RT-PCR技术检测了人口腔鳞状细胞癌细胞株SCC-25中Fas抗原的信使RNA。在无血清培养基中，单克隆抗Fas抗体诱导SCC-25细胞中Fas抗原的表达。Fas抗原定位于细胞质和细胞膜。被识别的蛋白质分子量为35000。抗fas单克隆抗体在SCC-25细胞中以时间依赖性的方式诱导细胞毒性长达8小时。使用Hoechst 33342染色，在抗fas单克隆抗体处理的细胞中观察到明显的核凝聚和染色质断裂。该抗体还以时间依赖性的方式诱导SCC-25细胞中的DNA阶梯形成。结果表明，抗Fas单克隆抗体可能通过与scc细胞中表达的Fas抗原结合介导细胞凋亡。

To determine the relationship between Fas antigen and apoptosis in oral epithelium, we investigated the expression of Fas antigen in oral mucosa by immunohistochemical and immunoblotting methods.Fas antigen distributed in stratum spinosum and basal part of the stratum coreneum in normal human gingiva. The estimated molecular weight of Fas antigen was calculated as 35,000, which consistent with the value reported for the Fas antigen. Expression of Fas antigen was related to the degree of the tumor differentiation.Using RT-PCR, messenger RNA for Fas antigen was detected in the human oral squamous cell carcinoma cell line, SCC-25. In serum-free medium, a monoclonal ante-Fas antibody induced expression of Fas antigen in SCC-25 cells. Fas antigen was localized to the cytoplasm and the cell membrane. The molecular weight of the protein recognized was 35,000. Anti-Fas monoclonal antibody induced cytotoxicity in SCC-25 cells in a time-dependent manner up to 8 h. Marked nuclear condensation and fragmentation of chromatin were observed in the anti-Fas monoclonal antibody-treated cells using Hoechst 33342 staining. This antibody also induced DNA ladder formation in SCC-25 cells in a time-dependent manner. The present results indicate that the anti Fas monoclonal antibody may mediate apoptosis by binding to the Fas antigen expressed in SCC-cells.