Functional expression of TRAIL by lymphoid and myeloid tumour cells

TRAIL is a potent death protein that favours the killing of various types o f cancer cells to normal cells, but under the right conditions TRAIL can al so kill activated human T cells. TRAIL mRNA is widely expressed by normal c ells but its expression by primary tumour cells is not known. In this study , primary tumour cells of haemopoietic origin constitutively expressed TRAI L mRNA and protein and were capable of inducing the apoptosis of target Jur kat cells in a dose-dependent manner. This killing effect was reversed by a nti-TRAIL antibody. The functional expression of TRAIL by lymphoid and myel oid malignant cells raises the possibility of its involvement in tumour cel l evasion of immunosurveillance, and could be related to spontaneous tumour cell death and necrosis.