title: [Biological mechanisms of human-derived leukemia stem cells senescence regulated by Angelica sinensis polysaccharide].
abstract: OBJECTIVE
  To explore the biological mechanisms underlying Angelica sindsis polysaccharide (ASP) -induced aging of human-derived leukemia stem cells (LSCs) in vitro.
  
  
  METHODS
  Acute myelogenous leukemia stem cells were isolated by magnetic activated cell sorting (MACS). The ability of LSC proliferation treated by various concentration of ASP(20-80 mg · L(-1)) in vitro for 48 hours were tested using cell counting Kit-8 ( CCK8) , colony forming were evaluated by methylcellulose CFU assay. The ultra structure changes of AML CD34+ CD38- cells were analyzed by transmission electron microscopy. The aging cells were detected with senescence-β-galactosidase Kit staining. Expression of aging-related p53, p21, p16, Rb mRNA and P16, Rb, CDK4 and Cyclin E protein were detected by quantitative reverse transcription polymerase chain reaction( qRT-PCR) and Western blotting, respectively.
  
  
  RESULTS
  The purity of the CD34 + CD38 - cells is (91.15 ± 2.41)% after sorted and showed good morphology. The proliferation of LSC was exhibited significantly concentration-dependent inhibited after exposure to various concentration of ASP. Treated by 40 mg · L(-1) ASP for 48 hours, the percentage of positive cells stained by SA-β-Gal was dramatically increased (P < 0.01) and the colony-formed ability has been weakened (P < 0.01). The observation of ultrastructure showed that cell heterochromatin condensation and fragmentation, mitochondrial swelling, lysosomes increased in number. Aging-related p53, p21, p16, Rb and P16, Rb were up-regulated, protein regulatory cell-cycle CDK4 and Cyclin E were down-regulated. ASP may induce the senescence of LSCs effectively in vitro, P16-Rb cell signaling pathway play a significant role in this process.
  
  
  CONCLUSIONS
  ASP can induce human leukemia stem cell senescence in vitro, the mechanism involved may be related to ASP regulation P16-Rb signaling pathways.
authors.forename: Dao-Yong
authors.initials: DY
authors.lastname: Jia
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Cheng-Peng
authors.initials: CP
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Meng-Si
authors.initials: MS
authors.lastname: Zhang
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Zhang
authors.lastname: Jing Peng-Wei
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Xu
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Wang
mesh_terms: D029971:Angelica sinensis / Q000737:chemistry*; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006801:Humans; D007938:Leukemia / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000187:drug effects*; D011134:Polysaccharides / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D018797:Cell Cycle Proteins; D004365:Drugs, Chinese Herbal; D011134:Polysaccharides