title: [Effect of Gli1 gene silencing on proliferation of K562 cells and its mechanisms].
abstract: OBJECTIVE
  To investigate the effect of Gli1 gene silencing by RNA interference (RNAi) on proliferation of K562 cells and its mechanisms.
  
  
  METHODS
  The small interference RNA (siRNA) was synthesized in vitro. K562 cells were transfected with Gli1 siRNA by the way of lipofection (lipofectamine 2000). Non-specific siRNA transfected cells were used as control. Transfection efficiencies of different siRNA concentrations were detected by flow cytometry and the best siRNA concentration was selected. The silencing effect of siRNA was demonstrated by real time PCR and Westem blot analysis. Cell proliferation was measured by MTT method, cell cycle by PI assay, c-myc and p21 mRNA level was detected by real time PCR analysis.
  
  
  RESULTS
  Transfection efficiency of siRNA was increased in a dose-dependent manner when siRNA concentration was below 200 pmol, and the highest transfection efficiency reached (80.11 ± 5.63)%. Both the mRNA and protein level of Gli1 was down-regulated in Gli1 specific siRNA group, the mRNA level was (52.60 ± 3.57)% of that of control group after 24 h (t = 20.33, P < 0.01) and the protein level was (79.31 ± 5.58)% of that of control group after 48 h (t = 6.54, P < 0.01). The cell proliferation rate in Gli1 siRNA group was (94.41 ± 3.58)% (t = 2.40, P = 0.05) and (90.22 ± 3.34)% (t = 4.37, P < 0.01) of that of control group after 24 h and 48 h, respectively. G(2)/M cell cycle arrest was observed, the mRNA level of c-myc was down-regulated while p21 was up-regulated in Gli1 siRNA group after 24 h and 48 h (P < 0.05).
  
  
  CONCLUSIONS
  Targeted silencing of Gli1 gene by RNAi inhibits the proliferation of K562 cells, which acts through the down-regulation of c-myc and up-regulation of p21 expression.
authors.affiliation: Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Wen-xia
authors.initials: WX
authors.lastname: Su
authors.forename: Yong-hong
authors.initials: YH
authors.lastname: Chen
authors.forename: Wen
authors.initials: W
authors.lastname: Zeng
authors.forename: Wen-li
authors.initials: WL
authors.lastname: Liu
authors.forename: Han-ying
authors.initials: HY
authors.lastname: Sun
mesh_terms: D049109:Cell Proliferation; D020868:Gene Silencing; D006801:Humans; D020014:K562 Cells; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection; D000071676:Zinc Finger Protein GLI1
chemical_list: C400551:GLI1 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014157:Transcription Factors; D000071676:Zinc Finger Protein GLI1