title: Carbon ion beam is more effective to induce cell death in sphere-type A172 human glioblastoma cells compared with X-rays.
abstract: OBJECTIVE
  To obtain human glioblastoma cells A172 expressing stem cell-related protein and comparison of radiosensitivity in these cells with X-rays and carbon beam.
  
  
  METHODS
  Human monolayer-type A172 glioblastoma cells were maintained in normal medium with 10% bovine serum. In order to obtain sphere-type A172 cells the medium was replaced with serum-free medium supplemented with growth factors. Both types of A172 cells were irradiated with either X-rays or carbon ion beams and their radiosensitivity was evaluated.
  
  
  RESULTS
  Serum-free medium induced expression of stem cell-related proteins in A172 cells along with the neurosphere-like appearance. These sphere-type cells were found resistant to both X-rays and carbon ion beams. Phosphorylation of histone H2A family member X persisted for a longer period in the cells exposed to carbon ion beams than in those exposed to X-rays and it disappeared quicker in the sphere type than in the monolayer type. Relative radioresistance of the sphere type cells was smaller for carbon ion beams than for X-rays.
  
  
  CONCLUSIONS
  We demonstrated that glioblastoma A172 cells with induced stem cell-related proteins turned resistant to irradiation. Accelerated heavy ion particles may have advantage over X-rays in overcoming the tumor resistance due to cell stemness.
authors.affiliation: Translational Research Center, Fukushima Medical University , Fukushima.
authors.forename: Momoko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hirakawa
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Yajima
authors.forename: Nakako
authors.initials: N
authors.lastname: Izumi-Nakajima
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Okayasu
authors.forename: Akira
authors.initials: A
authors.lastname: Fujimori
mesh_terms: D002244:Carbon / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects / Q000528:radiation effects; D016228:Endothelial Growth Factors / Q000494:pharmacology; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000528:radiation effects; D005909:Glioblastoma / Q000473:pathology*; D063193:Heavy Ion Radiotherapy; D006801:Humans; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D011836:Radiation Tolerance / Q000187:drug effects / Q000528:radiation effects; D014964:X-Ray Therapy
chemical_list: D016228:Endothelial Growth Factors; D005346:Fibroblast Growth Factors; D002244:Carbon; D004247:DNA
keywords: Glioblastoma cells; radiosensitivity; stem cells