Abnormal WT1 expression in the CD34-negative compartment in myelodysplastic bone marrow.
In normal bone marrow, WT1 expression is restricted to CD34+ cells. We assessed WT1 mRNA expression levels with quantitative, real-time reverse transcription polymerase chain reaction in normal, myelodysplastic (MDS) and secondary acute myeloid leukaemia (sAML) bone marrow subfractions, based on differentiation status. The highest WT1 expression was observed in the primitive CD34+ rhodamine-123 (rho) dull cells, both in healthy donors and MDS or sAML patients. In contrast to normal CD34-negative bone marrow cells, WT1 was present in CD34-negative bone marrow cells in 12 out of 13 MDS patients and two sAML samples. Further analysis of this aberrant WT1 expression was performed in the CD34-negative subfractions of three MDS patients. In one of these, WT1 expression was found exclusively in the erythroid cells. This patient was completely transfusion dependent and showed morphological dyserythropoiesis. In another MDS patient, WT1 expression was found in a non-erythroid compartment. We conclude that abnormal WT1 expression may contribute to the disturbed differentiation of haematopoietic cells in MDS patients.
Central Haematology Laboratory, University Medical Centre, St. Radboud, Nijmegen, The Netherlands.
Jeroen P
JP
Van Dijk
Gertrudis H J N
GH
Knops
Louis T F
LT
Van De Locht
Aswin L
AL
Menke
Joop H
JH
Jansen
Ewald J B M
EJ
Mensink
Reinier A P
RA
Raymakers
Theo
T
De Witte
D000208:Acute Disease; D018952:Antigens, CD34; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D007951:Leukemia, Myeloid / Q000276:immunology / Q000378:metabolism; D009190:Myelodysplastic Syndromes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025721:WT1 Proteins / Q000235:genetics*
D018952:Antigens, CD34; D012333:RNA, Messenger; D025721:WT1 Proteins