title: DNA damage foci formation and decline in two-dimensional monolayers and in three-dimensional human vessel models: differential effects according to radiation quality.
abstract: OBJECTIVE
  To analyze the effect of different radiation qualities on the kinetics of p53 Binding Protein 1 (53BP1) formation and decline in human three-dimensional (3-D) vessel models.
  
  
  METHODS
  Two-dimensional (2-D) and 3-D cultures of human umbilical vein cells were exposed to 80 cGy of Gamma radiation and high-energy protons and Fe ions. 53BP1 antibodies were used for foci visualization via immunocytochemistry. Computer analysis was used to determine the number and the size of foci up to 48 hours after irradiation.
  
  
  RESULTS
  DNA foci kinetics in 2-D and 3-D human vessel cultures show that foci formation and removal were the same in each type of culture. After 48 h, the number of foci induced by high-energy protons and gamma rays reduced to almost control levels while high linear energy transfer (LET) Fe particles produced more persistent damage.
  
  
  CONCLUSIONS
  The kinetics of radiation-induced 53BP1 foci in 3-D vessel models is essentially the same as in 2-D monolayers. Since the basal level of spontaneous foci is low in these differentiated non-proliferating cultures, the persistence of radiation-induced 53BP1 foci is detected longer than previously noted. Furthermore, analysis of foci sizes revealed that abnormal radiation-induced foci can persist even when foci frequencies are close to basal levels. The detection of these latent abnormalities could be useful for a more sensitive dosimetry.
authors.affiliation: Center for Radiological Research, College of Physicians and Surgeons, Columbia University, NY 10032, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Grabham
authors.forename: Alan
authors.initials: A
authors.lastname: Bigelow
authors.forename: Charles
authors.initials: C
authors.lastname: Geard
mesh_terms: D001808:Blood Vessels / Q000033:anatomy & histology / Q000378:metabolism* / Q000528:radiation effects*; D004249:DNA Damage; D005720:Gamma Rays / Q000009:adverse effects; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D021621:Imaging, Three-Dimensional; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D018499:Linear Energy Transfer; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011522:Protons / Q000009:adverse effects; D012062:Relative Biological Effectiveness; D000071857:Tumor Suppressor p53-Binding Protein 1
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D011522:Protons; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1