title: [miR-125b promotes proliferation of human acute myeloid leukemia cells by targeting Bak1].
abstract: OBJECTIVE
  To investigate miR- 125b regulation mechanism by identifying miR-125b target genes and its function in acute myeloid leukemia (AML).
  
  
  METHODS
  The bioinformatics software and database were applied to predict and analyze target genes of miR-125b. The vector contained the target gene 3'-UTR portion cloned into a luciferase reporter construct. A luciferase reporter assay was performed following co-transfection of small molecular miR-125b mimics and target gene wild-type or mutant plasmid into HEK-293T cells. Further in leukemia cell lines NB4 and HL-60, the protein level of target gene was measured by Western blot after overexpression miR-125b. Finally, the viabilities of NB4 and HL-60 cells were measured by CCK-8 assay at 24 h, 48 h, 72 h, 96 h after electroporation.
  
  
  RESULTS
  Bcl-2-antagonist/killer 1 (Bak1), a pro-apoptotic gene, was a target gene of miR-125b by software predicts. Reporter vector containing the 3'-UTR Bak1 wild and mutation sites were co-transfected with small molecule analogues of miR-125b in HEK-293T cells. Dual luciferase reporter gene assay system showed that miR-125b significantly suppresses the reporter gene activity containing Bak1 3'-UTR by about 53.8% (P<0.05), but it didn't suppresses the reporter gene activity containing 3'-UTR Bak1 mutation. Western blot showed that miR-125b mimics significantly down-regulated the expression of Bak1 in human leukemia cell lines NB4 and HL-60. Meanwhile, the growth rate of cells treated with miR-125b obviously increased compared with that in control by CCK-8 test (P<0.05).
  
  
  CONCLUSIONS
  Our findings strongly indicated that BAK1 was a downstream target gene of miR-125b, and miR-125b promoted proliferation in human AML cells at least partially by targeting Bak1, so we speculated that miR-125b as an oncogene could be a potential therapeutic target for treating AML.
authors.affiliation: The Department of Scientific Education Information, Guangzhou Women and Children Medical Center, Guangzhou 510623, China.
authors.forename: Qiao-hui
authors.initials: QH
authors.lastname: Zeng
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.forename: Xiao-dan
authors.initials: XD
authors.lastname: Liu
authors.forename: Wang
authors.initials: W
authors.lastname: Liao
authors.forename: Mu-xia
authors.initials: MX
authors.lastname: Yan
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005822:Genetic Vectors; D057809:HEK293 Cells; D018922:HL-60 Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D014162:Transfection; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: C494772:BAK1 protein, human; C531888:MIRN125 microRNA, human; D035683:MicroRNAs; D050998:bcl-2 Homologous Antagonist-Killer Protein