The Fas apoptotic pathway in cutaneous T-cell lymphomas: Frequent expression of phenotypes associated with resistance to apoptosis - 14/11/12
Abstract |
Background |
Low proliferation rates, sparse apoptotic cells, and resistance to chemotherapeutic agents suggest that defective apoptotic mechanisms may be important in the pathogenesis and progression of cutaneous T-cell lymphomas (CTCLs). Functional studies of CTCL cell lines and leukemic cells further support abnormal expression of Fas apoptotic pathway proteins as a mechanism for resistance to apoptosis.
Objective |
We sought to compare the Fas apoptotic pathway protein expression of mycosis fungoides (MF) with CD30+ lymphoproliferative disorders (CD30+d) in the context of insights gained from functional studies of CTCL cells.
Methods |
We conducted immunohistochemical analysis of 36 MF and 36 CD30+d skin biopsy specimens with antibodies against Fas, Fas ligand, FLICE-like inhibitory protein, Fas-associated death domain, and total and cleaved caspases 8 and 3.
Results |
Almost all MF lesions (94%) were Fas ligand–negative. In all, 64% of MF lesions were Fas low. An additional 25% of MF lesions were both Fas high and FLICE-like inhibitory protein high (Fas pathway inhibitor). Altogether, this equated to a phenotype predictive of apoptotic resistance in 89% of MF samples. In 9 of 10 cases of CD30+d, the apoptotic phenotype predictive of sensitivity/resistance correlated with signs of regression/progression, respectively.
Limitations |
The study is limited by its retrospective design.
Discussion |
Our in situ analysis of MF and CD30+d tissue samples correlates well with previous functional studies of CTCL cell lines and leukemic blood. Our data strengthen the hypothesis that abnormal expression of upstream Fas pathway factors (Fas, Fas ligand) and the inhibitor FLICE-like inhibitory protein contributes to defective apoptosis in CTCLs.
Le texte complet de cet article est disponible en PDF.Key words : anaplastic large cell lymphoma, apoptosis, caspases, extrinsic apoptotic pathway, Fas, Fas-associated death domain, Fas ligand, FLICE-like inhibitory protein, lymphomatoid papulosis, mycosis fungoides
Abbreviations used : ALCL, CD30+d, cFLIP, CTCL, DISC, FADD, FasL, LyP, mAB, MF, r, SzS
Plan
This material is based upon work funded by a Merit Review Award from the Biomedical Laboratory Research and Development Service of the VA Office of Research and Development. |
|
Conflicts of interest: None declared. |
|
Disclaimer: The contents do not represent the views of the Department of Veterans Affairs or the United States Government. |
|
Reprints not available from the authors. |
Vol 67 - N° 6
P. 1327.e1-1327.e10 - décembre 2012 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.
Déjà abonné à cette revue ?