BACKGROUND: Fas (APO-1/CD95) is a cell surface receptor that mediates apoptosis when it reacts with Fas ligand (FasL) or Fas antibody. Alterations of Fas and FasL expression have been demonstrated in various carcinomas. MATERIALS AND METHODS: We examined the alteration of Fas and FasL expression in seventy-eight specimens of colorectal adenoma and carcinoma by immunohistochemistry and real-time reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS: Our study revealed that the expression of Fas was reduced in colorectal adenoma and completely lost in some 60% of colorectal carcinomas. Fas expression was significantly down-regulated in liver metastasis compared with corresponding primary colorectal carcinoma. The expression of Fas significantly related to p53 status, tumor location and apoptosis in colorectal carcinoma. Up-regulation of FasL was not detected in colorectal adenoma, carcinoma cells and liver metastatic cancer cells. CONCLUSION: These results indicate that Fas may play an important role, not only in development but also progression, and that FasL is not always required for both development and progression in colorectal carcinomas.
BACKGROUND:Fas (APO-1/CD95) is a cell surface receptor that mediates apoptosis when it reacts with Fas ligand (FasL) or Fas antibody. Alterations of Fas and FasL expression have been demonstrated in various carcinomas. MATERIALS AND METHODS: We examined the alteration of Fas and FasL expression in seventy-eight specimens of colorectal adenoma and carcinoma by immunohistochemistry and real-time reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS: Our study revealed that the expression of Fas was reduced in colorectal adenoma and completely lost in some 60% of colorectal carcinomas. Fas expression was significantly down-regulated in liver metastasis compared with corresponding primary colorectal carcinoma. The expression of Fas significantly related to p53 status, tumor location and apoptosis in colorectal carcinoma. Up-regulation of FasL was not detected in colorectal adenoma, carcinoma cells and liver metastatic cancer cells. CONCLUSION: These results indicate that Fas may play an important role, not only in development but also progression, and that FasL is not always required for both development and progression in colorectal carcinomas.