title: [Effects of bone marrow stromal cells and VLA-4 antibody on apoptosis of childhood leukemia cells].
abstract: OBJECTIVE
  To study the protective effect of bone marrow stromal cells (BMSCs) upon childhood leukemia cells and the influence of VLA-4 antibody in vitro on leukemia cell apoptosis.
  
  
  METHODS
  BMSCs from children with acute leukemia-were isolated by human lymphocyte separation medium. BMSCs (adherent) and leukemia cells (suspended) were cultured in vitro. This study included four groups: leukemia cells alone (control), leukemia cells+BMSCs, leukemia cells+BMSCs supernatant and leukemia cells+BMSCs+VLA-4 antibody. The apoptosis rate of leukemia cells in the four groups was determined by Annexin Ⅴ-FITC double-labeled flow cytometry. The expression of survivin and bcl-2 genes in leukemia cells was ascertained by RT-PCR.
  
  
  RESULTS
  The apoptosis rate of leukemia cells in the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups was lower than that in the control group (P<0.05). Compared with the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups, the apoptosis rate of leukemia cells in the VLA-4 antibody group increased significantly (P<0.05). In the VLA-4 antibody group, the apoptosis rate of leukemia cells increased with prolonged culture time. There were significant differences in the apoptosis rate between 12 hrs and 24 hrs after VLA-4 antibody treatment (P<0.01). The expression of survivin and bcl-2 genes in leukemia cells from the VLA-4 antibody groups was reduced compared with that from the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups (P<0.05).
  
  
  CONCLUSIONS
  BMSCs play protective roles on leukemia cells. VLA-4 antibody can block the adhesion between BMSCs and leukemia cells and promote leukemia cell apoptosis.
authors.affiliation: Department of Pediatrics, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong 256603, China.
authors.forename: Zhong-Xia
authors.initials: ZX
authors.lastname: Li
authors.forename: Xiu-Hong
authors.initials: XH
authors.lastname: Jia
authors.forename: Jian-Chang
authors.initials: JC
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Han
mesh_terms: D000293:Adolescent; D000906:Antibodies / Q000627:therapeutic use*; D017209:Apoptosis; D001854:Bone Marrow Cells / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D019254:Genes, bcl-2; D006801:Humans; D007223:Infant; D051034:Inhibitor of Apoptosis Proteins; D039041:Integrin alpha4beta1 / Q000276:immunology*; D007938:Leukemia / Q000473:pathology* / Q000628:therapy; D008297:Male; D008869:Microtubule-Associated Proteins / Q000235:genetics; D017154:Stromal Cells / Q000502:physiology*; D000077022:Survivin
chemical_list: D000906:Antibodies; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D039041:Integrin alpha4beta1; D008869:Microtubule-Associated Proteins; D000077022:Survivin