title: Pharmacological inhibition of AKT activity in human CD34+cells enhances their ability to engraft immunodeficient mice.
abstract: Although practiced clinically for more than 40 years, the use of hematopoietic stem cell (HSC) transplantation remains limited by the inability to expand functional HSCs ex vivo. To determine the role of phosphoinositide 3-kinase (PI3K)/AKT signaling in human hematopoietic stem and progenitor cell (HSPC) maintenance, we examined the effect of genetic and pharmacological inhibition of AKT on human umbilical cord blood (UCB) CD34+cells. We found that knock-down of AKT1 in human UCB CD34+cells using short interfering RNAs targeting AKT1 enhances their quiescence and colony formation potential in vitro. We treated human UCB CD34+cells with an AKT-specific inhibitor (AKTi) and performed both in vitro and in vivo stem and progenitor cell assays. We found that ex vivo treatment of human HSPCs maintains CD34 expression and enhances colony formation in serial replating assays. Moreover, pharmacological inhibition of AKT enhances the short-term repopulating potential of human UCB CD34+cells in immunodeficient mice. Mechanistically, genetic and pharmacological inhibition of AKT activity promotes human HSPC quiescence. These preclinical results suggest a positive role for AKTi during ex vivo culture of human UCB HSPCs.
authors.affiliation: Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Sisi
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.affiliation: Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
authors.forename: Chonghua
authors.initials: C
authors.lastname: Yao
authors.affiliation: Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Reuben
authors.initials: R
authors.lastname: Kapur
authors.affiliation: Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Mervin C
authors.initials: MC
authors.lastname: Yoder
authors.affiliation: Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA. Electronic address: liu219@iu.edu.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism*; D015415:Biomarkers; D002453:Cell Cycle / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects; D003114:Colony-Forming Units Assay; D041905:Erythroid Cells / Q000166:cytology / Q000378:metabolism; D005312:Fetal Blood / Q000166:cytology; D055785:Gene Knockdown Techniques; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D016130:Immunophenotyping; D051379:Mice; D016513:Mice, SCID; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D034741:RNA, Small Interfering; D051057:Proto-Oncogene Proteins c-akt