title: 5-Azacytidine supports the long-term repopulating activity of cord blood CD34(+) cells.
abstract: DNA methylation plays important roles in a wide range of biological phenomena, especially in the embryonic development and tumorigenesis. However, correlations between differentiation and DNA methylation have not been clarified well in each differentiation system. In this study, we focused our attention on regulatory roles of DNA methylation in normal hematopoietic differentiation using a demethylating reagent, 5-azacytidine (5-AzaC). As a source of hematopoietic progenitor cells, we used CD34(+) cells prepared from human umbilical cord blood and examined the effects of 5-AzaC on the colony-forming activity and the long-term culture-initiating (LTC-IC) activity of these cells. 5-AzaC treatment increased LTC-IC frequency 1.57- to 2.50-fold as compared to the nontreated control. In parallel to this, immunoblotting analysis showed that the intensity of overall DNA methylation decreased after 5-AzaC treatment. These results indicated the involvement of DNA methylation and demethylation in controlling immaturity of hematopoietic progenitor cells and the usefulness of 5-AzaC for regulating this immaturity.
authors.affiliation: Fujisaki Cell Center, Hayashibara Biochemical Laboratories, Inc., Okayama, Japan. fcch@hayashibara.co.jp
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Akira
authors.initials: A
authors.lastname: Harashima
authors.forename: Ayumi
authors.initials: A
authors.lastname: Okochi
authors.forename: Mayuko
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Shuji
authors.initials: S
authors.lastname: Nakamura
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Motoda
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Yamasaki
authors.forename: Kunzo
authors.initials: K
authors.lastname: Orita
mesh_terms: D018952:Antigens, CD34 / Q000097:blood; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001374:Azacitidine / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D003114:Colony-Forming Units Assay / Q000379:methods; D019175:DNA Methylation / Q000187:drug effects; D005312:Fetal Blood / Q000166:cytology* / Q000187:drug effects* / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000276:immunology; D006801:Humans; D015151:Immunoblotting
chemical_list: D018952:Antigens, CD34; D000964:Antimetabolites, Antineoplastic; D001374:Azacitidine