title: Very low frequencies of human normal CD34+ haematopoietic progenitor cells express the Wilms' tumour gene WT1 at levels similar to those in leukaemia cells.
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.
authors.affiliation: Department of Molecular Medicine, Osaka University Medical School, Osaka, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Hosen
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sonoda
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Oji
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Minamiguchi
authors.forename: Hiroya
authors.initials: H
authors.lastname: Tamaki
authors.forename: Manabu
authors.initials: M
authors.lastname: Kawakami
authors.forename: Momotaro
authors.initials: M
authors.lastname: Asada
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kanato
authors.forename: Mari
authors.initials: M
authors.lastname: Motomura
authors.forename: Masaki
authors.initials: M
authors.lastname: Murakami
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujioka
authors.forename: Tomoki
authors.initials: T
authors.lastname: Masuda
authors.forename: Eui Ho
authors.initials: EH
authors.lastname: Kim
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuboi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Oka
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Soma
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ogawa
authors.forename: Haruo
authors.initials: H
authors.lastname: Sugiyama
mesh_terms: D018952:Antigens, CD34; D005434:Flow Cytometry / Q000379:methods; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D007938:Leukemia / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025721:WT1 Proteins / Q000235:genetics*
chemical_list: D018952:Antigens, CD34; D025721:WT1 Proteins