title: Proteomic analysis of effects by x-rays and heavy ion in HeLa cells.
abstract: BACKGROUND
  Carbon ion therapy may be better against cancer than the effects of a photon beam. To investigate a biological advantage of carbon ion beam over X-rays, the radioresistant cell line HeLa cells were used. Radiation-induced changes in the biological processes were investigated post-irradiation at 1 h by a clinically relevant radiation dose (2 Gy X-ray and 2 Gy carbon beam). The differential expression proteins were collected for analysing biological effects.
  
  
  METHODS
  The radioresistant cell line Hela cells were used. In our study, the stable isotope labelling with amino acids (SILAC) method coupled with 2D-LC-LTQ Orbitrap mass spectrometry was applied to identity and quantify the differentially expressed proteins after irradiation. The Western blotting experiment was used to validate the data.
  
  
  RESULTS
  A total of 123 and 155 significantly changed proteins were evaluated with treatment of 2 Gy carbon and X-rays after radiation 1 h, respectively. These deregulated proteins were found to be mainly involved in several kinds of metabolism processes through Gene Ontology (GO) enrichment analysis. The two groups perform different response to different types of irradiation.
  
  
  CONCLUSIONS
  The radioresistance of the cancer cells treated with 2 Gy X-rays irradiation may be largely due to glycolysis enhancement, while the greater killing effect of 2 Gy carbon may be due to unchanged glycolysis and decreased amino acid metabolism.
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Zhitong
authors.initials: Z
authors.lastname: Bing
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China ; Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Yang
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Biochemistry and Molecular Laboratory, Medical College of Henan University, Henan, China.
authors.forename: Fengling
authors.initials: F
authors.lastname: Wang
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Caiyong
authors.initials: C
authors.lastname: Ye
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Jintu
authors.initials: J
authors.lastname: Sun
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
keywords: 2D-LC-MS/MS; Carbon ion; Gene Ontology enrichment; SILAC; X-rays