Fas/APO-1 (CD95) expression in myelodysplastic syndromes.
Increased apoptosis of myeloid precursors appears to contribute to the pathophysiology of cytopenias in myelodysplastic syndromes (MDS). Fas /APO-1(CD95) is a cell surface protein inducing an apoptotic signal after its binding to Fas ligand or to a functional anti-Fas antibody. Here we studied Fas expression by immunocytochemistry on marrow slides from 30 cases of MDS. Increased Fas expression in erythroblasts and/or immature granulocytes, compared to controls, was seen in 12 (40%) of the cases. In addition, in 16 of the 18 cases with > or = 5% marrow blasts, a variable proportion of blasts expressed Fas. Increased apoptosis was found by morphological analysis and/or TUNEL technique in marrow cells from 8 of the 26 cases analyzed (31%) The ability of Fas antigen to trigger apoptosis was studied after addition of a functional anti Fas antibody in 5 of the patients with Fas overexpression. Addition of this antibody, however, only lead to mild increase of apoptosis in immature granulocytes (but not other myeloid cells) in 2 of the 5 cases. Thus, increased Fas expression is seen in myeloid and/or blast cells in the majority of MDS cases. However, the relationship between this finding and increased apoptosis in MDS still remains to be established.
Laboratoire d'Hématologie A Hôpital Calmette, France.
P
P
Lepelley
N
N
Grardel
O
O
Erny
T
T
Iaru
V
V
Obein
A
A
Cosson
P
P
Fenaux
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000276:immunology; D017209:Apoptosis; D001853:Bone Marrow / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics* / Q000473:pathology; D019014:fas Receptor / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology
D000911:Antibodies, Monoclonal; D019014:fas Receptor