title: Effects of Alpha Particle and Proton Beam Irradiation as Putative Cross-Talk between A549 Cancer Cells and the Endothelial Cells in a Co-Culture System.
abstract: BACKGROUND
  High-LET ion irradiation is being more and more often used to control tumors in patients. Given that tumors are now considered as complex organs composed of multiple cell types that can influence radiosensitivity, we investigated the effects of proton and alpha particle irradiation on the possible radioprotective cross-talk between cancer and endothelial cells.
  
  
  METHODS
  We designed new irradiation chambers that allow co-culture study of cells irradiated with a particle beam. A549 lung carcinoma cells and endothelial cells (EC) were exposed to 1.5 Gy of proton beam or 1 and 2 Gy of alpha particles. Cell responses were studied by clonogenic assays and cell cycle was analyzed by flow cytometry. Gene expression studies were performed using Taqman low density array and by RT-qPCR.
  
  
  RESULTS
  A549 cells and EC displayed similar survival fraction and they had similar cell cycle distribution when irradiated alone or in co-culture. Both types of irradiation induced the overexpression of genes involved in cell growth, inflammation and angiogenesis.
  
  
  CONCLUSIONS
  We set up new irradiation chamber in which two cell types were irradiated together with a particle beam. We could not show that tumor cells and endothelial cells were able to protect each other from particle irradiation. Gene expression changes were observed after particle irradiation that could suggest a possible radioprotective inter-cellular communication between the two cell types but further investigations are needed to confirm these results.
authors: URBC-NARILIS, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium. helene.riquier@gmail.com.
authors: Hélène
authors: H
authors: Riquier
authors: URBC-NARILIS, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium. abel_denis@hotmail.com.
authors: Denis
authors: D
authors: Abel
authors: LARN-PMR, NARILIS, University of Namur, Namur 5000, Belgium. a.wera@surrey.ac.uk.
authors: Anne-Catherine
authors: AC
authors: Wera
authors: LARN-PMR, NARILIS, University of Namur, Namur 5000, Belgium. anne-catherine.heuskin@unamur.be.
authors: Anne-Catherine
authors: AC
authors: Heuskin
authors: URBC-NARILIS, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium. geraldine.genard@unamur.be.
authors: Géraldine
authors: G
authors: Genard
authors: LARN-PMR, NARILIS, University of Namur, Namur 5000, Belgium. stephane.lucas@unamur.be.
authors: Stéphane
authors: S
authors: Lucas
authors: URBC-NARILIS, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium. carine.michiels@unamur.be.
authors: Carine
authors: C
authors: Michiels