title: [Influence of knock-down of miR-21 expression on the radiosensitivity of glioma SHG-44 cells].
abstract: OBJECTIVE
  To explore the influence of knock-down of miR-21 expression on the radiosensitivity of radioresistant glioma SHG-44 cells and its mechanism.
  
  
  METHODS
  Radioresistant cell line SHG-44(R) cells were established from radiosensitive parental SHG-44 glioma cells. Then the expression levels of miR-21 in SHG-44(R) and SHG-44 were determined by quantitative real-time PCR. The effect of miR-21 on the radiosensitivity was assessed in SHG-44(R) with miR-21 inhibitor to decrease the miR-21 expression.
  
  
  RESULTS
  miR-21 was up-regulated 1.49-fold in SHG-44(R) cells relative to the SHG-44 cells. But after transfection with As-miR-21, the miR-21 expression in SHG-44(R) cells was knocked down significantly. As-miR-21 combined with radiation could synergistically enhanced mitotic death and apoptosis of SHG-44(R) cells, with SER of D(0) and D(q) being equal to 1.48 and 1.54, respectively. Expression levels of caspase-3 in the radiation group, AS-miR-21 transfection group and combination group were 2.24 ± 0.14, 2.05 ± 0.19 and 5.72 ± 0.45, respectively, and its expression in the combination group was higher than that in the other two groups.
  
  
  CONCLUSIONS
  miR-21 may be involved in the formation of radioresistance of glioma cells and as a potential target for enhancing the response of radioresistant-glioma cells to radiotheapy.
authors.affiliation: Department of Radiation Oncology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China. zhjuying@sohu.com
authors.forename: Ju-ying
authors.initials: JY
authors.lastname: Zhou
authors.forename: Chong
authors.initials: C
authors.lastname: Zhou
authors.forename: Li-li
authors.initials: LL
authors.lastname: Wang
authors.forename: Xiao-ting
authors.initials: XT
authors.lastname: Xu
authors.forename: Song-bing
authors.initials: SB
authors.lastname: Qin
mesh_terms: D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D011836:Radiation Tolerance; D014162:Transfection
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; C505407:CASP3 protein, human; D053148:Caspase 3