| |
|
|
|
|
|
|
|||
|
Blood, 1 May 2008, Vol. 111, No. 9, pp. 4780-4787. Prepublished online as a Blood First Edition Paper on February 26, 2008; DOI 10.1182/blood-2007-08-109074.
NEOPLASIA Resistance to FasL and tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in Sézary syndrome T-cells associated with impaired death receptor and FLICE-inhibitory protein expression1 Department of Dermatology, Zürich University Hospital, Zürich, Switzerland; 2 Louis-Jeantet Skin Cancer Laboratory, Department of Pathology and Immunology, University Medical Center, Geneva, Switzerland; 3 Department of Dermatology, University Hospital, Geneva, Switzerland; 4 Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia; and 5 Topotarget Switzerland, Lausanne, Switzerland
Because of the low proliferative potential of tumor cells in patients with Sézary syndrome (SzS), their accumulation has been suggested to be due to defective regulation of apoptosis. We analyzed the sensitivity to soluble Fas-ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), 2 members of the TNF superfamily in peripheral blood leukocytes (PBL) from patients with SzS. Compared with healthy donors, CD4+ cells from patients with SzS were completely resistant to FasL in 9 of 16 cases. Of these 9 FasL-resistant cases, 4 revealed a loss in Fas (CD95) expression, whereas the remaining 5 exhibited normal or enhanced Fas expression. In the latter 5 cases, the apoptosis inhibitor cFLIP was overexpressed in CD4+/CD26– tumor cells compared with CD4+/CD26– cells from Fas-expressing FasL-sensitive patients and healthy donors. Furthermore, resistance to TRAIL and tumor cell-restricted loss of TRAIL-receptor 2 were observed in 16 of 16 SzS PBLs. It is noteworthy that resistance to FasL could be overcome by the use of a hexameric FasL or upon exposure of SzS cells to interferon-
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||
| Copyright © 2008 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||||