title: JAS-R, a new megakaryo-erythroid leukemic cell line that secretes erythropoietin.
abstract: BACKGROUND
  The processes of leukemogenesis and differentiation of the megakaryo-erythroid lineage remain poorly understood. Leukemic cell lines derived from megakaryocytic leukemia are valuable reagents for studies on these events.
  
  
  METHODS
  A new cell line, JAS-R, was established from a 64-year-old patient with acute megakaryocytic leukemia (AML M7). Its characteristics were studied by morphological, immunophenotypic and molecular biological analysis.
  
  
  RESULTS
  Immunophenotyping showed that the JAS-R cells were positive for CD33, CD41 and CD61, as well as moderately to weakly positive for CD4, CD7, CD13 and glycophorin A. Chromosomal analysis revealed a composite karyotype, but no major translocation abnormalities were observed. Electron microscopy disclosed that the JAS-R cells had numerous surface blebs and some cells also had alpha-granules and demarcation membranes. The mRNAs of 4 major proteins (platelet factor 4, beta-thromboglobulin, selectin-P and thrombospondin 1) found in alpha-granules were all expressed by the JAS-R cells. In particular, expression of platelet factor 4 was high. To further characterize JAS-R cells, comparison with 4 other megakaryo-etythroid cell lines (CMK, MEG-01, K562 and KU812) was done by gene expression profiling using an oligo-DNA microarray. The results showed that JAS-R was a distinctive cell line. It was noteworthy that the JAS-R cells secreted erythropoietin and expressed erythropoietin receptor. A neutralizing antibody for erythropoietin partly inhibited the proliferation of the cells.
  
  
  CONCLUSIONS
  JAS-R may be a useful cell line for investigating the differentiation and leukemogenesis of megakaryo-erythroid cells and for studying the influence of erythropoietin on these cells.
authors.affiliation: Division of General Medicine, Aoto Hospital, Jikei University School of Medicine, Tokyo 125-8506, Japan.
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Sekikawa
authors.forename: Satsuki
authors.initials: S
authors.lastname: Iwase
authors.forename: Shinobu
authors.initials: S
authors.lastname: Saito
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Arakawa
authors.forename: Miyuki
authors.initials: M
authors.lastname: Agawa
authors.forename: Junko
authors.initials: J
authors.lastname: Horiguchi-Yamada
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamada
mesh_terms: D045744:Cell Line, Tumor / Q000473:pathology*; D004921:Erythropoietin / Q000378:metabolism*; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D020014:K562 Cells; D007621:Karyotyping; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics / Q000473:pathology*; D007947:Leukemia, Megakaryoblastic, Acute / Q000235:genetics / Q000473:pathology*; D008875:Middle Aged
chemical_list: D004921:Erythropoietin