title: Survivin may enhance DNA double-strand break repair capability by up-regulating Ku70 in human KB cells.
abstract: BACKGROUND
  Survivin, expressed in almost all types of human malignancies, functions as a key factor in radioresistance primarily by inhibiting apoptosis. This study was conducted to investigate whether survivin plays a role in the DNA repair process in the KB human squamous cell carcinoma cell line.
  
  
  METHODS
  A stable KB cell line overexpressing survivin was established through the use of pIRES2-EGFP vector containing the coding region of survivin. Cells were then irradiated with X-rays and evaluated for DNA double-strand breaks (DSBs) by comet assay and flow cytometry for phospho-histone gammaH2AX. The protein levels of some DSB repair genes were detected by Western blotting analysis.
  
  
  RESULTS
  Comet assay and flow cytometry for phospho-histone gammaH2AX showed that overexpression of survivin resulted in significantly fewer DSBs in irradiated cells. Among the DSB repair genes detected, the protein level of Ku70 was up-regulated in survivin-overexpressing KB cells.
  
  
  CONCLUSIONS
  This finding suggests that survivin may enhance DSB repair capability in KB cells by up-regulating Ku70.
authors.affiliation: Faculty of Preventive Medicine, Medical College, Huangjiahu Campus, Wuhan University of Science and Technology, Wuhan 430065, PR China. jianggaofeng@yahoo.com.cn
authors.forename: Gaofeng
authors.initials: G
authors.lastname: Jiang
authors.forename: Bo
authors.initials: B
authors.lastname: Ren
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.forename: Shizhen
authors.initials: S
authors.lastname: Song
authors.forename: Changcai
authors.initials: C
authors.lastname: Zhu
authors.forename: Fangli
authors.initials: F
authors.lastname: Ye