功能性Fas 配体在大肠癌细胞的表达及其调控

 目的　研究功能性 Fas配体在大肠癌细胞的表达及其调控。方法　分别采用反转录 -聚合酶链反应和氚释放细胞活性测定技术检测了大肠癌细胞株中 Fas配体 m RNA表达和 Fas依赖的细胞毒活性及其调控。结果　在检测的六株大肠癌细胞中 ,全部表达 Fas配体 m RNA。部分大肠癌细胞具有 Fas依赖的细胞毒活性。其中 DLD- 1细胞活性具有量效关系 ,并且乙酸肉豆寇佛波醇 (PMA)和离子霉素 (ionomycine)刺激能显著增强 DLD- 1的细胞毒活性。结论　至少部分大肠癌细胞表达功能性 Fas配体 ,并可能以此反击机体免疫系统 ,逃避免疫监督。

Expression and Modulation of Functional Fas ligand in Human Colon Cancer Cells

Objective To investigate the expression and modulation of functional Fas ligand in human colon carcinoma cells.Methods A total of six human colon cancer cell lines were examined for the expression of Fas ligand mRNA and the expression of Fas ligand surface protein,as well as the Fas|dependent cytotoxicity and its modulation by using RT|PCR,flow cytomtry and |TdR release assay,respectively.Results The results showed that Fas ligand mRNA was expressed in all of these six cancer cell lines.Fas ligand surface protein was expressed on a part of these cancer cells.Fas|dependent cytotoxicity to hFas transfectant was exerted in a part of these cancer cells.The cytotoxicity was significantly enhanced by PMA and ionomycin.Conclusion These data suggest that FasL expressing in human colon cancer cells may be regulated by endogeneous factors in the microenvironment of the host and faciliate to escape from the host immune system.