title: Comparison of X-ray and alpha particle effects on a human cancer and endothelial cells: survival curves and gene expression profiles.
abstract: OBJECTIVE
  Tumours are now considered as complex tissues including endothelial cells of the tumour vasculature, which can decrease radiotherapy efficacy. It is thus important to better characterise the response of both types of cells to irradiation. This study investigated the effects of X-ray and alpha particle irradiation on cancer and endothelial cells.
  
  
  METHODS
  A549 non-small-cell lung adenocarcinoma cells and human endothelial cells (EC) were exposed to X-rays or alpha particles. Responses were studied by clonogenic assays and nuclei staining. A gene expression study was performed by using Taqman low density array and the results were validated by qRT-PCR and ELISA.
  
  
  RESULTS
  The relative biological effectiveness of alpha particles was estimated to be 5.5 and 4.6 for 10% survival of A549 cells and EC, respectively. Nuclei staining indicated that mitotic catastrophe was the main type of cell death induced by X-rays and alpha particles. Both ionising radiations induced the overexpression of genes involved in cell growth, inflammation and angiogenesis.
  
  
  CONCLUSIONS
  Alpha particle irradiations are more effective than X-rays. The gene expression changes observed in both cell types after alpha particle or X-ray exposure showed possible crosstalk between both cell types that may induce the development of radioresistance.
authors.affiliation: URBC-NARILIS, Namur, Belgium.
authors.forename: Hélène
authors.initials: H
authors.lastname: Riquier
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Wera
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Heuskin
authors.forename: Olivier
authors.initials: O
authors.lastname: Feron
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lucas
authors.forename: Carine
authors.initials: C
authors.lastname: Michiels
mesh_terms: D000512:Alpha Particles / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D002470:Cell Survival / Q000528:radiation effects; D018932:Chemokine CCL2 / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism / Q000528:radiation effects*; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D011836:Radiation Tolerance; D012062:Relative Biological Effectiveness; D059467:Transcriptome; D014964:X-Ray Therapy; D014965:X-Rays
chemical_list: C111835:CCL2 protein, human; D018932:Chemokine CCL2; D016209:Interleukin-8