Human colon cancer cells express functional fas ligand

Fas ligand (FasL) belongs to the TNF superfamily. FasL is reported to be detected on activated lymphocytes and in some tissues other than lymphoid cells. We investigated expression and function of FasL on human colon cancer cells. Six colon cancer cell lines used in this experiment expressed FasL mRNA, whereas it was not detected on normal fibroblasts. FasL protein was detected by flow cytometry on DLD-1, LoVo, COLO 320DM and HCT 116 and by immunohistochemical staining in DLD-1, LoVo, HCT 116 and RPMI 4788. DLD 1, LoVo and WiDr were cytotoxic against human Fas-expressing cells. It is concluded that human colon cancer cells, at least in part, express functional FasL and are cytotoxic against Fas-expressing cells.