FasL EXPRESSION IN HUMAN COLON CARCINOMAS

摘要

Objective:The Fas and Fas ligand (FasL) play an important role in maintaining immune privilege on malignant tumors. In present study, we investigated the expression of FasL in SW480 and LS174 human colon carcinoma cell lines and twenty primary colon carcinoma specimens. Methods: The expression of FasL in human colon carcinoma cell lines and primary colon carcinomas specimens was detected by immunohistochemistry and Reverse Transcription-PCR (RT-PCR). Results: We found that all of detected human colon carcinoma cell lines and primary colon carcinoma specimens constitutively expressed FasL at the mRNA and protein level. However, the expression of FasL was not found in normal colon epithelial cells. Conclusion: The expression of FasL may occur during malignant transformation from normal colon epithelial cells to colon carcinoma cells. Our results suggest that tumor cells kill cytotoxic T lymphocytes (CTLS) and natural killer (NK) cells by expression of FasL. It may be a new mechanism for tumor cells to escape the host's immune surveillance. The expression of FasL may contribute to the formation of colon carcinomas.