title: Differential gene expression profiles of DNA repair genes in esophageal cancer cells after X-ray irradiation.
abstract: OBJECTIVE
  Various factors affect the radioresistance of tumor cells, with unknown molecular mechanism(s). Many genes have been found to associate with the radioresistance of tumor cells, however, the precise mechanism of these genes have not been elucidated. This paper was to analyze the differential expressions of DNA repair genes in esophageal carcinoma cells at different time after X-ray irradiation, and to investigate the role of these DNA repair genes in radiation resistance.
  
  
  METHODS
  Esophageal cancer parental cells Seg-1 were treated with continuous 2 Gy of fractionated irradiation until the total dose reached 60 Gy to establish the radioresistant cell line Seg-1R. Total RNA was extracted from each cell line at 0, 8, and 24 h after irradiation. Illumine Human-6 V3 microarray was used to identify differentially expressed genes between parental and radioresistant cells. Ten genes involved in DNA repair were obtained and their expressions at different time points after irradiation were analyzed by Gene Ontology analysis.
  
  
  RESULTS
  Ten DNA repair associated genes were found to be differentially expressed. Three of these genes, SLK, HMGB1, and PMS1, were not only differentially expressed between parental and radioresistant cell lines, but also expressed differently at different time points after irradiation in the same cell line.
  
  
  CONCLUSIONS
  PMS1 may be an important factor involved in the mechanism of radioresistance of esophageal carcinoma cells.
authors.affiliation: Department of Pharmacology, Hebei North University, Zhangjiakou, Hebei 075000, PR China.
authors.forename: Hai
authors.initials: H
authors.lastname: Zhang
authors.forename: Xian-Shu
authors.initials: XS
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Hong-Zhen
authors.initials: HZ
authors.lastname: Li
authors.forename: De-Min
authors.initials: DM
authors.lastname: Zhou
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.forename: Dan-Shen
authors.initials: DS
authors.lastname: Zhang
mesh_terms: D045744:Cell Line, Tumor / Q000528:radiation effects; D004260:DNA Repair / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects*; D006801:Humans; D000070956:MutL Proteins; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011836:Radiation Tolerance; D059467:Transcriptome; D014965:X-Rays
chemical_list: D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; C088996:PMS1 protein, human; D000070956:MutL Proteins