title: Ex vivo expansion of human mobilized peripheral blood stem cells using epigenetic modifiers.
abstract: BACKGROUND
  Epigenetic modifications likely control the fate of hematopoietic stem cells (HSCs). The chromatin-modifying agents (CMAs), 5-aza-2'-deoxycytidine (5azaD) and trichostatin A (TSA), have previously been shown to expand HSCs from cord blood and marrow. Here we assessed whether CMA can also expand HSCs present in growth factor-mobilized human peripheral blood (MPB).
  
  
  METHODS
  5azaD and TSA were sequentially added to CD34+ MPB cells in the presence of cytokines, and the cells were cultured for 9 days.
  
  
  RESULTS
  After culture, a 3.6 ± 0.5-fold expansion of CD34+CD90+ cells, a 10.1 ± 0.5-fold expansion of primitive colony-forming unit (CFU)-mix, and a 2.2 ± 0.5-fold expansion of long-term cobblestone-area-forming cells (CAFCs) was observed in 5azaD/TSA-expanded cells. By contrast, cells cultured in cytokines without 5azaD/TSA displayed no expansion; rather, a reduction in CD34+CD90+ cells (0.7 ± 0.1-fold) and CAFCs (0.3 ± 0.1-fold) from their initial numbers was observed. Global hypomethylation corresponding with increased transcript levels of several genes implicated in HSC self-renewal, including HOXB4, GATA2, and EZH2, was observed in 5azaD/TSA-expanded MPB cells in contrast to controls. 5azaD/TSA-expanded MPB cells retained in vivo hematopoietic engraftment capacity.
  
  
  CONCLUSIONS
  MPB CD34+ cells from donors can be expanded using 5azaD/TSA, and these expanded cells retain in vivo hematopoietic reconstitution capacity. This strategy may prove to be potentially useful to augment HSC numbers for patients who fail to mobilize.
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.|University of Illinois Cancer Center, Chicago, Illinois.
authors.forename: Santosh
authors.initials: S
authors.lastname: Saraf
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Araki
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Petro
authors.affiliation: UI Hospital Stem Cell Laboratory, Blood & Marrow Transplant Program, Chicago, Illinois.
authors.forename: Youngmin
authors.initials: Y
authors.lastname: Park
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Simona
authors.initials: S
authors.lastname: Taioli
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Kazumi G
authors.initials: KG
authors.lastname: Yoshinaga
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Emre
authors.initials: E
authors.lastname: Koca
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.|UI Hospital Stem Cell Laboratory, Blood & Marrow Transplant Program, Chicago, Illinois.|University of Illinois Cancer Center, Chicago, Illinois.
authors.forename: Damiano
authors.initials: D
authors.lastname: Rondelli
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.|UI Hospital Stem Cell Laboratory, Blood & Marrow Transplant Program, Chicago, Illinois.|University of Illinois Cancer Center, Chicago, Illinois.
authors.forename: Nadim
authors.initials: N
authors.lastname: Mahmud
mesh_terms: D000328:Adult; D000818:Animals; D018952:Antigens, CD34 / Q000032:analysis; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001773:Blood Cells / Q000166:cytology / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D002452:Cell Count; D002455:Cell Division; D002478:Cells, Cultured; D042002:Chromatin Assembly and Disassembly / Q000187:drug effects; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000494:pharmacology; D019175:DNA Methylation / Q000187:drug effects; D000077209:Decitabine; D044127:Epigenesis, Genetic / Q000187:drug effects*; D005312:Fetal Blood / Q000166:cytology; D006085:Graft Survival; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D064593:Heterografts; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D018189:Immunomagnetic Separation; D007231:Infant, Newborn; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D036102:Peripheral Blood Stem Cell Transplantation; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D018952:Antigens, CD34; D016207:Cytokines; D006877:Hydroxamic Acids; C012589:trichostatin A; D000077209:Decitabine; D001374:Azacitidine