大肠癌细胞功能性Fas配体的表达度与肿瘤免疫逃逸的关系  

Relationship between expression of functional Fas ligand in human colon cancer cells and tumor's immune escape

作　　者：徐彤[1] 李强[1] 郝希山[1] 

机构地区：[1]天津医科大学附属肿瘤医院腹外科,天津市300060

出　　处：《世界华人消化杂志》2004年第9期2066-2069,共4页World Chinese Journal of Digestology

基　　金：天津市科委重大科技攻关项目基金资助;No.003119711~~

摘　　要：目的:表达Fas配体(fas ligand,FasL的肿瘤周围激活的Fas 阳性淋巴细胞凋亡异常增加.肿瘤的发生在很大程度上是因为转化的细胞不能正常凋亡所致.观察Fas与FasL在结肠癌细胞株的表达,在体外验证结肠癌细胞SW620是否可以诱导淋巴细胞发生凋亡. 方法:用免疫组织化学SABC法观察结肠癌细胞系和Jurkat T淋巴细胞系Fas与FasL的表达,为癌细胞的Fas和FasL 的功能提供形态学依据.采用非放射性细胞毒分析,测定SW620结肠癌细胞与Jurkat靶细胞共培养后LDH释放值检测效应细胞的杀伤效应. 结果:结肠癌SW620细胞FasL染色呈阳性反应,阳性反应物主要定位于癌细胞的胞膜及核周区,而Fas染色几乎呈阴性反应.Jurkat细胞系Fas,FasL,免疫组化染色呈阳性反应,阳性反应物主要定位于癌细胞的胞膜.CytoTox96 非放射性细胞毒分析显示大肠癌SW620细胞系与激活的T 细胞(Jurkat T细胞)共培养,诱导对Fas介导的凋亡敏感的T淋巴细胞(Jurkat T细胞)明显凋亡,并随着SW620接种浓度增加和共培养时间的延长,Jurkat T细胞凋亡的比例显著增加.用含有乙酸肉豆佛波醇(phorbol 12-Inyristate 13-ac- etace,PMA)加离子霉素(ionomycin)的DMEM培养基孵育48 h的大肠癌SW620细胞系与激活的T细胞(Jurkat T细胞) 共培养,Jurkat T细胞凋亡的比例也明显增加. 结论:结肠癌细胞SW620表达功能性FasL,能杀伤Fas阳性Jurkat T淋巴细胞,形成免疫逃逸.AIM: The evidence has pointed to an abnormal increase in apoptosis among activated Fas-positive lymphocytes, mainly in the periphery of the Fas ligand (FasL)-express-ing tumors. On the other hand, to a great extent, the occurrence of tumor is due to the fact that the converted cells cannot undergo a normal process of apoptosis. This study was designed to detect the expression of FasL in human colon carcinoma cells and to determine whether colon cancer cells SW620 could induce apoptosis of lymphocytes by Fas system in vitro. METHODS: By using immunohistochemical SABC method, the expression of Fas receptor and Fas ligand in SW620 colon carcinoma cell line and Jurkat T cells was observed so as to supply morphological evidence for the functions of Fas receptor and Fas ligand. In an effort to examine the cytotoxicity of effector cells, CytoTox 96 non-radioactive cytotoxicity assay was adopted to measure LDH releasing value after the SW620 cells were co-cultured with the Jurkat T lymphocytes. RESULTS: It was shown that the Fas ligand of colon carcinoma SW620 cells was positive and the positive substances were distributed in the cell membrane and cytoplasm, and the Fas receptor of colon carcinoma SW620 cells was negative. The Fas receptor and the Fas ligand of Jurkat T lymphocytes turned out to be positive. The positive substances were distributed in the cell membrane. The non- radioactive cytotoxicity assay showed that the apoptotic rate of Jurkat cells remarkably increased with the increase of planting concentration of SW620 and co-cultured time with the Jurkat T lymphocytes. The cytotoxicity was significantly enhanced by PMA and ionomycin. CONCLUSION: The functional expression of FasL in the colon carcinoma SW620 cells can inversely induce apoptosis of Fas-expressing Jurkat T lymphocytes for immune escape.

关 键 词：T细胞 表达 结肠癌细胞 FAS配体 T淋巴细胞 凋亡 共培养 阳性反应 DMEM 霉素 

分 类 号：R735.34[医药卫生—肿瘤]