title: Cyogenetics effects in AG01522 human primary fibroblasts exposed to low doses of radiations with different quality.
abstract: OBJECTIVE
  Biological effects produced by low doses of ionizing radiations, though relevant for the risk assessment, have not been fully elucidated. The aim of the present work was to evaluate cytogenetic endpoints, as telomere dysfunctions and chromosome instability in the low-dose range as a function of radiation quality. In particular, we analyzed whether the telomere length was modulated, as well as the involvement of telomeres in chromosomal alterations at anaphase, and the yield of stable simple and complex chromosome aberrations.
  
  
  METHODS
  AG01522 human primary fibroblasts were irradiated with 0.1-1 Gy of X-rays, protons (28.5 keV/μm), and 4He(2+) ions (62 keV/μm). Frequency of chromosome bridges carrying or not telomeric signals and telomere length were measured in irradiated samples up to 72 h. Moreover, chromosome instability was measured using multicolor fluorescence in situ hybridization (mFISH).
  
  
  RESULTS
  The results evidenced a linear energy transfer (LET)- and dose-dependent response in the frequency of anaphase bridges induction and in their persistence as a function of time. However, neither variation in telomere length and telomere loss, nor in the proportion of bridges bearing telomeric signals, was detected, thus indicating a minor role of telomeres in the generation of the radiation-induced chromosome bridges. Chromosome instability followed a linear-dependence with dose and LET, showing a far higher extent of complex translocations in helium-ion-irradiated cells than in proton- or X-ray-irradiated samples.
  
  
  CONCLUSIONS
  Altogether, the results indicated the lack of telomere involvement in cytogenetic effects induced by low-dose ionizing radiation. On the contrary, chromosome aberration yield and spectrum were LET- and dose-dependent.
authors.affiliation: Department of Computer Science, University Roma Tre, Rome, Italy.
authors.forename: Dino
authors.initials: D
authors.lastname: Nieri
authors.forename: Francesco
authors.initials: F
authors.lastname: Berardinelli
authors.forename: Antonella
authors.initials: A
authors.lastname: Sgura
authors.forename: Roberto
authors.initials: R
authors.lastname: Cherubini
authors.forename: Viviana
authors.initials: V
authors.lastname: De Nadal
authors.forename: Silvia
authors.initials: S
authors.lastname: Gerardi
authors.forename: Caterina
authors.initials: C
authors.lastname: Tanzarella
authors.forename: Antonio
authors.initials: A
authors.lastname: Antoccia
mesh_terms: D000705:Anaphase; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D003582:Cytogenetics; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000528:radiation effects / Q000648:ultrastructure; D006801:Humans; D018499:Linear Energy Transfer; D016615:Telomere / Q000528:radiation effects*