title: Set9, NF-κB, and microRNA-21 mediate berberine-induced apoptosis of human multiple myeloma cells.
abstract: OBJECTIVE
  To investigate the mechanisms by which berberine suppressed the proliferation of human multiple myeloma cells.
  
  
  METHODS
  Human U266 multiple myeloma cell line was tested. Cell proliferation, apoptosis, ultramicrostructure and secretion function were examined using Cell Counting Kit-8 (CCK8), flow cytometry (FCM), electron and fluorescence microscopy, as well as ELISA assay. The microRNAs (miRs) and transcription factors in U266 cells were detected using arrays and verified by qRT-PCR. EMSA and luciferase assays were used to verify the p65-dependent transactivation of miR-21 gene.
  
  
  RESULTS
  Treatment of U266 cells with berberine (40-160 μmol/L) suppressed cell proliferation and IL-6 secretion in dose- and time-dependent manners. Meanwhile, berberine dose-dependently induced ROS generation, G(2)/M phase arrest and apoptosis in U266 cells, and decreased the levels of miR-21 and Bcl-2. Overexpression of miR-21 counteracted berberine-induced suppression of cell proliferation and IL-6 secretion. In U266 cells treated with berberine (80 μmol/L), the activity of NF-κB was decreased by approximately 50%, followed by significant reduction of miR-21 level. berberine (80-160 μmol/L) increased the level of Set9 (lysine methyltransferase) by more than 2-fold, caused methylation of the RelA subunit, which inhibited NF-κB nuclear translocation and miR-21 transcription. In U266 cells treated with berberine (80 μmol/L), knockdown of Set9 with siRNAs significantly increased NF-κB protein level accompanying with a partial recovery of proliferation.
  
  
  CONCLUSIONS
  In U266 cells, berberine suppresses NF-κB nuclear translocation via Set9-mediated lysine methylation, leads to decrease in the levels miR21 and Bcl-2, which induces ROS generation and apoptosis.
authors.affiliation: Oncology Department of Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Hu
authors.forename: Kun-peng
authors.initials: KP
authors.lastname: Li
authors.forename: Xiu-ju
authors.initials: XJ
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhi-gang
authors.initials: ZG
authors.lastname: Lu
authors.forename: Rui-hong
authors.initials: RH
authors.lastname: Dong
authors.forename: Hong-bo
authors.initials: HB
authors.lastname: Guo
authors.forename: Mei-xia
authors.initials: MX
authors.lastname: Zhang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001599:Berberine / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D010946:Plants, Medicinal / Q000737:chemistry
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D015850:Interleukin-6; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D016328:NF-kappa B; D001599:Berberine; D011495:Histone-Lysine N-Methyltransferase; C540312:SETD7 protein, human