Fas antigen and Fas ligand with Oral Disease

为探讨Fas抗原与口腔上皮细胞凋亡的关系，采用免疫组化和免疫印迹法检测了Fas抗原在正常人牙龈组织中的表达，结果表明Fas抗原在牙龈组织中主要分布于棘层和角质层基底部。Fas抗原的估计分子量计算为35，000，这与Fas抗原报告的值一致。Fas抗原的表达与肿瘤分化程度有关，应用RT-PCR方法检测人口腔鳞癌细胞株SCC-25中Fas抗原的mRNA表达。在无血清培养基中，抗Fas单克隆抗体诱导SCC-25细胞表达Fas抗原。Fas抗原定位于细胞质和细胞膜。识别的蛋白质的分子量为35，000。抗Fas单克隆抗体对SCC-25细胞的杀伤作用呈时间依赖性，最长可达8h。Hoechst 33342染色可见Fas单克隆抗体处理的细胞核固缩和染色质断裂。该抗体还以时间依赖性方式诱导SCC-25细胞中DNA梯状条带的形成。本研究结果表明，抗Fas单克隆抗体可能通过与SCC细胞中表达的Fas抗原结合而介导细胞凋亡。

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.