title: [Research on regulation of cell senescence by miRNA-34a].
abstract: OBJECTIVE
  To determine miRNA-34a regulated cell senescence indirectly through targeting silent mating-type information regulation 2 homologue 1 (SIRT1) in vitro experiment.
  
  
  METHODS
  A constructed pre-miRNA -34a expression vector and a miRNA-1792 expression vector (not directly against any gene) were transfected into HEK293 and HUVEC cell lines respectively. The expression levels of SIRT1 in each cell groups were detected by RT-PCR and Western blot. The HUVEC cells were divided into different group: transfected with pre-miRNA-34a expression vector (HUVEC-pre-miRNA-34a), transfected with miRNA-1792 expression vector (HUVEC-pre-miRNA-1792), treated HUVEC cell with SIRT1 activator resveratrol (final concentration 1 micromol/L, treatment for 2 h)(HUVEC-Res), and HUVEC cells without any treatment as the control. Comet assay was applied to detect the oxidative damage of above-mentioned cells after H2O2 treatment for 2 h, and beta-galactosidase (SA-beta-gal) staining was used to detect the senescence of them in different time points after doxorubicin treatment for 2 h.
  
  
  RESULTS
  Pre-miRNA-34a expression vector was constructed successfully by sequencing confirmation. RT-PCR and Western blot indicated that the overexpression of miRNA-34a down regulated mRNA and protein level of SIRT1 in HEK293-miRNA-34a and HUVEC-miRNA-34a cell groups (P < 0.001). Comet assay revealed that HUVEC-miRNA-34a cell group was the most sensitive to H2O2 treatment, and the DNA damage of HUVEC-Res cell group was the most minor. HUVEC-miRNA-34a cell group displayed higher frequency of SA-beta-gal staining than that of other cell groups.
  
  
  CONCLUSIONS
  miRNA-34a regulated cell senescence indirectly through targeting SIRT1.
authors.affiliation: Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Yang
authors.forename: Xue-Jiao
authors.initials: XJ
authors.lastname: Fan
authors.forename: Wen-Ting
authors.initials: WT
authors.lastname: Du
authors.forename: Peng-Liang
authors.initials: PL
authors.lastname: Ren
authors.forename: Ji
authors.initials: J
authors.lastname: Liu
mesh_terms: D016922:Cellular Senescence; D015536:Down-Regulation; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D012333:RNA, Messenger; D000077185:Resveratrol; D056564:Sirtuin 1 / Q000378:metabolism*; D013267:Stilbenes; D014162:Transfection
chemical_list: C522425:MIRN34 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D013267:Stilbenes; C447939:SIRT1 protein, human; D056564:Sirtuin 1; D000077185:Resveratrol