In addition to the full length mRNA activated human peripheral blood mononuclear cells (PBMC) and T cell tumor lines express several alternatively spliced Fas variants. At least five of these code for soluble Fas (CD95) molecules. In vitro studies suggest that these soluble Fas isoforms inhibit apoptosis induced by agonistic antibodies and, more importantly, by the natural Fas ligand in Fas-bea...

PURPOSE Oxaliplatin-5-fluorouracil combinations have increased responses in first-line therapy up to 40% in advanced colorectal cancer. Unfortunately, those patients who will respond are unknown and initially sensitive patients become rapidly resistant to current therapies. FAS (CD95) and FAS ligand (FASL; CD95L) have been implicated in chemosensitivity through leading to apoptosis in response ...

It has been believed that the Fas expressed on human peripheral blood T cells (PBT) is nonfunctional, because these cells are insensitive to agonistic anti-Fas/Apo-1 mAbs that efficiently kill in vitro-activated T cells and many Fas-expressing cell lines. Here, we demonstrate that membrane-bound Fas ligand (FasL) kills both fresh and in vitro-activated PBT, indicating that the Fas expressed on ...

Altered expression of the Fas-Fas ligand apoptotic pathway leads to lymphoproliferative and autoimmune diseases. In lpr/lpr mice and children with autoimmune lymphoproliferative syndrome, defective apoptosis is due to Fas mutations. Large granular lymphocyte (LGL) leukemia is a clonal lymphoproliferative disorder associated with rheumatoid arthritis. Leukemic LGLs are resistant to Fas-dependent...

Recent studies have revealed an anticipated link between a soluble receptor antagonist for the proapoptotic protein Fas and cancer. In this issue, Ugurel et al. (1) demonstrate that sFas levels correlate with poor prognosis and decreased overall survival in patients with melanoma. On the basis of available evidence, it appears that nonhematopoietic tumor development and progression may represen...

Using fluorescent variants of Fas and FasL, we show that membrane FasL and Fas form supramolecular clusters that are of flexible shape, but nevertheless stable and persistent. Membrane FasL-induced Fas clusters were formed in caspase-8- or FADD-deficient cells or when a cytoplasmic deletion mutant of Fas was used suggesting that cluster formation is independent of the assembly of the cytoplasmi...