title: Blood group B gene is barely expressed in in vitro erythroid culture of Bm-derived CD34+ cells without an erythroid cell-specific regulatory element.
abstract: OBJECTIVE
  Previously, a weak phenotype Am or Bm was assumed to be caused by a reduction of A or B gene expression in bone marrow cells, but not in mucus-secreting cells. However, ABO expression has not been examined in erythroid progenitor cells of Am or Bm individuals.
  
  
  METHODS
  We carried out in vitro erythroid differentiation of CD34(+) cells from peripheral blood of a Bm individual harbouring a 3.0-kb deletion including an erythroid cell-specific regulatory element, named the +5.8-kb site, in intron 1 of the human ABO blood group gene.
  
  
  RESULTS
  During the in vitro differentiation of CD34(+) cells from this Bm individual into erythroid cells, B-antigens were not detectable on the cultured cells by flow cytometric analysis, and allele-specific RT-PCR consistently detected the transcripts from the O allele, but not from the B allele. Moreover, chromatin immunoprecipitation assay demonstrated that both RUNX1 and GATA-2 or GATA-1 were bound to the +5.8-kb site in cultured erythroid cells expressing ABO.
  
  
  CONCLUSIONS
  It is likely that the +5.8-kb site enhances transcription from the ABO promoter in erythroid cells through binding of RUNX1 and GATA-2 or GATA-1.
authors.affiliation: Legal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Sano
authors.forename: M
authors.initials: M
authors.lastname: Nogawa
authors.forename: T
authors.initials: T
authors.lastname: Nakajima
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: R
authors.initials: R
authors.lastname: Kubo
authors.forename: Y
authors.initials: Y
authors.lastname: Kominato
authors.forename: A
authors.initials: A
authors.lastname: Yokohama
authors.forename: J
authors.initials: J
authors.lastname: Tsukada
authors.forename: H
authors.initials: H
authors.lastname: Yamao
authors.forename: T
authors.initials: T
authors.lastname: Kishida
authors.forename: K
authors.initials: K
authors.lastname: Ogasawara
authors.forename: M
authors.initials: M
authors.lastname: Uchikawa
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics* / Q000378:metabolism; D000483:Alleles; D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D041905:Erythroid Cells / Q000166:cytology / Q000276:immunology*; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000276:immunology*; D006410:Hematopoiesis; D006801:Humans; D011401:Promoter Regions, Genetic
chemical_list: D000017:ABO Blood-Group System; D018952:Antigens, CD34
keywords: ABO gene; Bm; enhancer