title: [Down-regulation of miR-21 expression enhances the radiosensitivity of TE-1 cells in vitro].
abstract: OBJECTIVE
  To study the effect of miR-21 down-regulation on the radiosensitivity of TE-1 cells in vitro.
  
  
  METHODS
  TE-1 cells were transfected via lentivirus with a vector containing the antisense oligonucleotides of miR21, and the subclones with stable down-regulation of miR21 expression were selected with puromycin and designated as TE-1-miR21(-), whose expression level of miR21 was determined using real-time quantitative PCR. The radiosensitivity of TE-1 and TE-1-miR21(-) cells were evaluated with colony formation assay, and the expressions of β-catenin was determined using Western blotting and RT-PCR. Flow cytometry was used to analyze the proportion of p75NTR(+) cells in TE-1 and TE-1-miR21(-) cells.
  
  
  RESULTS
  A cell subclone stably expressing a low level of miR21 was obtained and verified by real-time quantitative PCR. Colony formation assay showed an enhanced the radiosensitivity of TE-1-miR21(-) cells compared to parental TE-1 cells. RT-PCR revealed no significant changes in β-catenin mRNA expression in TE-1-miR21(-) cells, whereas its β-catenin protein expression was markedly suppressed by high-dose (8 and 10 Gy) irradiation. Flow cytometry assay showed a decreased proportion of p75NTR(+) cells in TE-1-miR21(-) cells compared to that in TE-1 cells.
  
  
  CONCLUSIONS
  Down-regulation of miR21 can enhance the radiosensitivity of TE-1 cells, which might result from the inactivation of wnt/β-catenin signal pathway and a decreased p75NTR(+) cell proportion.
authors.affiliation: Department of Radiotherapy, First Affiliated Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, China. Lixiaoqing_1221@126.com
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.forename: Shaomin
authors.initials: S
authors.lastname: Che
authors.forename: Xiaozhi
authors.initials: X
authors.lastname: Zhang
mesh_terms: D045744:Cell Line, Tumor; D015536:Down-Regulation; D005822:Genetic Vectors; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D011836:Radiation Tolerance; D051153:Wnt Proteins / Q000378:metabolism; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000378:metabolism
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D051153:Wnt Proteins; D051176:beta Catenin