Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 21, 2005; 11(23): 3632-3635
Published online Jun 21, 2005. doi: 10.3748/wjg.v11.i23.3632
Fas ligand expression in colon cancer: A possible mechanism of tumor immune privilege
Wei Zhang, Er-Xun Ding, Qiang Wang, Da-Qiao Zhu, Jin He, Yu-Li Li, Yuan-He Wang
Wei Zhang, Er-Xun Ding, Qiang Wang, Yuan-He Wang, Department of General Surgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China
Jin He, Yu-Li Li, Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China
Da-Qiao Zhu, Department of Clinical Nursing, Department of Nursing, Second Military Medical University, Shanghai 200433, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 39900143
Correspondence to: Dr. Wei Zhang, Department of General Surgery, Changzheng Hospital, Second Military Medical University, Shanghai 20003, China. zhangwei412@yahoo.com.cn
Telephone: +86-21-63610109-73312
Received: July 12, 2004
Revised: July 13, 2004
Accepted: August 30, 2004
Published online: June 21, 2005
Abstract

AIM: To detect the expression of Fas ligand (FasL) in colon cancer tissues and cell lines and analyze the function of FasL-expressing colon cancer cells in inducing Fas-sensitive T lymphocyte apoptosis.

METHODS: Ninety surgically resected colon cancer tissues and 15 hepatic metastasis specimens were investigated by immunohistochemical method with normal colon mucosa and colon adenoma as control. The relationship between FasL expression and pathologic features was also analyzed. FasL expression of 4 colon cancer cell lines, SW620, Lovo, LS-174T and SW1116, were detected by Western blotting assay. The function of FasL expressed on colon cancer cells was determined by coculture assay with Jurkat T lymphocytes, the apoptotic rate of which was detected by flow cytometry assay.

RESULTS: Fifty-six (62.22%) cases of all the 90 colon cancer tissues and all (100%) the liver metastasis specimens expressed FasL, significantly higher than normal colon mucosa and colonic adenoma. Higher expression of FasL was found in more advanced stage of colon cancer and in cancer tissues with lymphatic or hepatic metastasis. All the colon cancer cell lines were found to express FasL. After coculture with the SW1116 cells for 24 h with an effector: target ratio 10:1, the rate of apoptosis of Jurkat cells rose from 1.9% to 21.0%.

CONCLUSION: The expression of FasL is upregulated in colon cancer and the functionally expressed FasL can induce apoptosis of Fas-expressing T lymphocytes.

Keywords: Fas ligand, Colon cancer, Immune privilege