5‐azacytidine supports the long‐term repopulating activity of cord blood CD34+ cells

• Published in: American journal of hematology Vol. 77; no. 3; pp. 313 - 315
• Main Authors: Suzuki, Motoyuki, Harashima, Akira, Okochi, Ayumi, Yamamoto, Mayuko, Nakamura, Shuji, Motoda, Ryuichi, Yamasaki, Fumiyuki, Orita, Kunzo
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2004; Wiley-Liss
• Subjects: 5‐azacytidine; Antigens, CD34 - blood; Antimetabolites, Antineoplastic - pharmacology; Azacitidine - pharmacology; Biological and medical sciences; Cell Differentiation - drug effects; Colony-Forming Units Assay - methods; DNA Methylation - drug effects; Fetal Blood - cytology; Fetal Blood - drug effects; Fetal Blood - immunology; Hematologic and hematopoietic diseases; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - drug effects; Hematopoietic Stem Cells - immunology; Humans; Immunoblotting; LTC‐IC; Medical sciences; umbilical cord blood CD34+ cells; Antineoplastic agent; LTC-IC; Hematology; 5-azacytidine; Activity; Long term; Blood; Azanucleoside; Blood cell; Antimetabolic; Azacitidine; Triazine derivatives; umbilical cord blood CD34+ cells; Umbilical cord; Long term culture initiating cell
• ISSN: 0361-8609; 1096-8652
• DOI: 10.1002/ajh.20178

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. Am. J. Hematol. 77:313–315, 2004. © 2004 Wiley‐Liss, Inc.