title: Pure curcumin decreases the expression of WT1 by upregulation of miR-15a and miR-16-1 in leukemic cells.
abstract: BACKGROUND
  Pure curcumin has been reported to down-regulate the expression of WT1 in leukemic cells. However, the molecular mechanism underlying the down-regulation of WT1 by curcumin is not completely delineated. The purpose of this present study is to identify a new miRNA-mediated mechanism which plays an important role in the anti-proliferation effects of curcumin in leukemic cells.
  
  
  METHODS
  K562 and HL-60 cells were treated with different concentrations of curcumin for 24 and 48 hours, the level of miR-15a/16-1 and WT1 were detected by qRT-PCR and Western blotting. WT1 expression and cell proliferation were detected by Western blotting and CCK-8, after curcumin treated-K562 and HL-60 cells were transfected with anti-miR-15a/16-1 oligonucleotides.
  
  
  RESULTS
  We found that pure curcumin upregulated the expression of miR-15a/16-1 and downregulated the expression of WT1 in leukemic cells and primary acute myeloid leukemia (AML) cells. Overexpression of miR-15a/16-1 deduced the protein level of WT1 in leukemic cells, but downregulation of WT1 by siRNA-WT1 could not increase the expression of miR-15a/16-1 in leukemic cells. These results reveal that curcumin induced-upregulation of miR-15a/16-1 is an early event upstream to downregulation of WT1. Furthermore, anti-miR-15a/16-1 oligonucleotides (AMO) partly reversed the downregulation of WT1 induced by pure curcumin in leukemic cells and AMO promoted the growth of curcumin treated-K562 and HL-60 cells.
  
  
  CONCLUSIONS
  Thus, these data suggest for the first time that pure curcumin downregulated the expression of WT1 partly by upregulating the expression of miR-15a/16-1 in leukemic cells. miR-15a/16-1 mediated WT1 downregulation plays an important role in the anti-proliferation effect of curcumin in leukemic cells.
authors.affiliation: Laboratory of Internal Medicine, The First Affiliated Hospital of Wenzhou Medical College, 2 FuXue Road, Wenzhou 325000, China.
authors.forename: Shen-meng
authors.initials: SM
authors.lastname: Gao
authors.forename: Jun-jun
authors.initials: JJ
authors.lastname: Yang
authors.forename: Chi-qi
authors.initials: CQ
authors.lastname: Chen
authors.forename: Jun-jie
authors.initials: JJ
authors.lastname: Chen
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Ye
authors.forename: Lu-yao
authors.initials: LY
authors.lastname: Wang
authors.forename: Jian-bo
authors.initials: JB
authors.lastname: Wu
authors.forename: Chong-yun
authors.initials: CY
authors.lastname: Xing
authors.forename: Kang
authors.initials: K
authors.lastname: Yu
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology*; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D018922:HL-60 Cells; D006801:Humans; D020014:K562 Cells; D007938:Leukemia / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D009841:Oligonucleotides / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics; D025721:WT1 Proteins / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; C505361:MIRN15 microRNA, human; C505362:MIRN16 microRNA, human; D035683:MicroRNAs; D009841:Oligonucleotides; D025721:WT1 Proteins; D003474:Curcumin