title: [Radiobiological characteristics and MRN complex expression of human nasopharyngeal carcinoma cell lines].
abstract: OBJECTIVE
  To study the radiobiological characteristic of human nasopharyngeal carcinoma cell lines CNE1 and CNE2 and the changes in expression MRN (Mre11-Rad50-Nbs1) complex in the cell lines exposed to irradiation.
  
  
  METHODS
  CNE1 and CNE2 were irradiated by a linear accelerator. Radiobiological characteristics were detected by colony assay and MTT assay. MRN complex expression were examined by Western blot.
  
  
  RESULTS
  Surviving fraction at 2 Gy (SF2), quasi-threshold Dose (Dq), and mean lethal dose (Do) of CNE1 were 0.56, 1.449 Gy and 1.480 Gy; SF2, Dq, and Do of CNE2 were 0.44, 0.776 Gy and 1.685 Gy, respectively. Survival fraction of CNE1 at the day 6 after 4 Gy irradiation was 0.59 and that of CNE2 was 0.79 when compared with control, with the up-regulated expressions of Rad50 in CNE1 and Mre11, Rad50 and Nbs1 in CNE2 (P < 0.05).
  
  
  CONCLUSIONS
  CNE1 and CNE2 were sensitive to radiation, but there were radioresistance cells in CNE2. The expressions of some components of MRN complex were up-regulated to repair DNA lesions induced by radiation.
authors.affiliation: Third Affiliated Hospital of Sun Yet-sun University, Guangzhou 510630, China.
authors.forename: Jian-cong
authors.initials: JC
authors.lastname: Huang
authors.forename: Ge-hua
authors.initials: GH
authors.lastname: Zhang
authors.forename: Jing-jia
authors.initials: JJ
authors.lastname: Li
authors.forename: Rui-cheng
authors.initials: RC
authors.lastname: Yan
authors.forename: Xi-fu
authors.initials: XF
authors.lastname: Wu
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.forename: Ming-yue
authors.initials: MY
authors.lastname: Lü
authors.forename: Feng-an
authors.initials: FA
authors.lastname: Xie
mesh_terms: D017766:Acid Anhydride Hydrolases; D002277:Carcinoma; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000528:radiation effects; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D000076228:MRE11 Homologue Protein; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000473:pathology* / Q000532:radiotherapy; D009687:Nuclear Proteins / Q000378:metabolism*; D011836:Radiation Tolerance
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C121766:MRE11 protein, human; C112156:NBN protein, human; D009687:Nuclear Proteins; D000076228:MRE11 Homologue Protein; D017766:Acid Anhydride Hydrolases; C112158:RAD50 protein, human; D045643:DNA Repair Enzymes