title: The therapeutic effect of photon irradiation on viable glioblastoma cells is reinforced by hyperbaric oxygen.
abstract: BACKGROUND
  Hyperbaric oxygen (HBO) seems to intensify the effect of ionising radiation. We investigated whether HBO combined with irradiation decreases the capability of U251 glioblastoma cells for relapse and metastasis.
  
  
  METHODS
  Cells were treated with O2 at 1.3 bar and then irradiated with 2 Gy photons. Clonogenic survival was tested with colony formation. Motility is an important feature of metastasis and was measured with time-lapse videography.
  
  
  RESULTS
  The clonogenic survival diminished by 22% through HBO, by 49% through irradiation, and by 70% through the combination of both. The accumulated distance travelled by cells fell by 3% with HBO, rose by 17% with irradiation, but was reduced by 11% with their combination. The respective values for the Euclidean distance travelled were +8%, +47% and -14%. Compared to normoxic irradiation, additional HBO lowered travel by 41%.
  
  
  CONCLUSIONS
  HBO strengthens the effect of irradiation on clonogenic survival and reverses radiation-induced increase in the mobility of cells.
authors: Institute for Molecular Oncology, Radio-Biology and Experimental Radiotherapy, University Medical Centre Marienhospital, Ruhr-University Bochum, Herne, Germany helmut.buehler@rub.de.
authors: Helmut
authors: H
authors: Bühler
authors: Department of Radiotherapy and Radio-Oncology, University Medical Centre Marienhospital, Ruhr-University Bochum, Herne, Germany.
authors: Gerfried L
authors: GL
authors: Strohm
authors: Institute for Molecular Oncology, Radio-Biology and Experimental Radiotherapy, University Medical Centre Marienhospital, Ruhr-University Bochum, Herne, Germany.
authors: Pascaline
authors: P
authors: Nguemgo-Kouam
authors: Druckkammerzentrum Hannover, Hannover, Germany.
authors: Hans
authors: H
authors: Lamm
authors: Department of Radiotherapy and Radio-Oncology, University Medical Centre Marienhospital, Ruhr-University Bochum, Herne, Germany.
authors: Khashayar
authors: K
authors: Fakhrian
authors: Department of Radiotherapy and Radio-Oncology, University Medical Centre Marienhospital, Ruhr-University Bochum, Herne, Germany.
authors: Irenäus A
authors: IA
authors: Adamietz
mesh_terms: D045744:Cell Line, Tumor; D005909:Glioblastoma / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D006931:Hyperbaric Oxygenation; D009362:Neoplasm Metastasis; D017785:Photons
keywords: Glioblastoma; HBO; clonogenicity; hyperbaric oxygen; motility; time-lapse videography