Very low frequencies of human normal CD34+ haematopoietic progenitor cells express the Wilms' tumour gene WT1 at levels similar to those in leukaemia cells

Br J Haematol. 2002 Feb;116(2):409-20. doi: 10.1046/j.1365-2141.2002.03261.x.

Abstract

The Wilms' tumour gene, WT1, is expressed at high levels in leukaemia cells and plays an important role in leukaemogenesis. WT1 is also expressed in human normal CD34+ bone marrow (BM) cells at about 100 times lower levels than in leukaemia cells. To identify and characterize WT1-expressing cells in CD34+ BM cells, they were sorted into single cells and analysed for WT1 expression using two kinds of single-cell reverse transcriptase polymerase chain reaction (RT-PCR) methods. Using the semiquantitative single-cell polyA-PCR + sequence-specific (SS)-PCR method, WT1 expression was detected in four (1.3%) out of 319 CD34+ BM single cells. To confirm the above results, a single-cell nested sequence-specific (NSS)-RT-PCR method that was less quantitative but more sensitive than the polyA-PCR + SS-PCR method was also performed, and WT1 expression was detected in 15 (1.1%) out of 1315 CD34+ BM single cells. In total, WT1 expression was found in 19 (1.2%) out of 1634 CD34+ BM single cells. No significant differences in the frequencies of WT1-expressing cells were found between CD34+CD38- and CD34+CD38+ BM single cells. Furthermore, WT1-expressing CD34+ BM single cells expressed WT1 at levels similar to those in K562 leukaemia single cells. Analysis of lineage-specific and cell cycle gene expression in WT1-expressing CD34+ BM single cells showed that the WT1 gene could be expressed in both uncommitted, dormant CD34+CD38- and lineage-committed, proliferating CD34+CD38+ BM cells. Our results could indicate that these WT1-expressing CD34+ BM cells were normal counterparts of leukaemia cells.

Publication types

  • Comparative Study

MeSH terms

  • Antigens, CD34*
  • Flow Cytometry / methods
  • Gene Expression
  • Hematopoietic Stem Cells / metabolism*
  • Humans
  • Leukemia / genetics*
  • Polymerase Chain Reaction / methods
  • Reverse Transcriptase Polymerase Chain Reaction
  • WT1 Proteins / genetics*

Substances

  • Antigens, CD34
  • WT1 Proteins