title: Identification of heat shock protein 27 as a radioresistance-related protein in nasopharyngeal carcinoma cells.
abstract: OBJECTIVE
  To identify the proteins involved in radioresistance in nasopharyngeal cancer (NPC) cells.
  
  
  METHODS
  Sublethal ionizing radiation was applied to establish a radioresistant NPC cell line from its parental NPC cell line CNE1. Clonogenic survival assay, cell growth assay and flow cytometry analysis were used to examine the difference of radiosensitivity in the radioresistant CNE1 cells (CNE1-IR) and control CNE1 cells. Comparative proteomics was performed to identify the differential proteins in the two cell lines. Association of HSP27, one of upregulated proteins in CNE1-IR cells, with NPC cell radioresistance was selected for further investigation using antisense oligonucleotides (ASOs), clonogenic survival assay, Hoechst 33258 staining of apoptotic cells and MTT assay of cell viability.
  
  
  RESULTS
  Radioresistant NPC cell line CNE1-IR derived from its parental cell line CNE1 was established. Thirteen differential proteins in the CNE1-IR and CNE1 cells were identified by proteomics, and differential expression of HSP27, one of identified proteins, was selectively confirmed by western blot. Inhibition of HSP27 expression by HSP27 ASOs decreased clonogenic survival and cell viability and increased cell apoptosis of CNE1-IR cells after irradiation, that is, enhanced radiosensitivity of CNE1-IR cells.
  
  
  CONCLUSIONS
  The data suggest that HSP27 is a radioresistant protein in NPC cells, and its upregulation may be involved in the NPC radioresistance.
authors: Department of Histology and Embryology, Xiangya School Medicine, Central South University, Changsha, 410008, China.
authors: Bin
authors: B
authors: Zhang
authors: Jia-Quan
authors: JQ
authors: Qu
authors: Liang
authors: L
authors: Xiao
authors: Hong
authors: H
authors: Yi
authors: Peng-Fei
authors: PF
authors: Zhang
authors: Mao-Yu
authors: MY
authors: Li
authors: Rong
authors: R
authors: Hu
authors: Xun-Xun
authors: XX
authors: Wan
authors: Qiu-Yan
authors: QY
authors: He
authors: Jian-Huang
authors: JH
authors: Li
authors: Xu
authors: X
authors: Ye
authors: Zhi-Qiang
authors: ZQ
authors: Xiao
authors: Xue-Ping
authors: XP
authors: Feng
mesh_terms: D017209:Apoptosis / Q000235:genetics / Q000528:radiation effects; D002277:Carcinoma; D002453:Cell Cycle / Q000235:genetics / Q000528:radiation effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics / Q000528:radiation effects; D015536:Down-Regulation / Q000528:radiation effects; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism*; D006360:Heat-Shock Proteins; D006801:Humans; D018832:Molecular Chaperones; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D040901:Proteomics / Q000379:methods; D011836:Radiation Tolerance / Q000235:genetics; D015854:Up-Regulation / Q000528:radiation effects
chemical_list: D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones