title: mBAND and mFISH analysis of chromosomal aberrations and breakpoint distribution in chromosome 1 of AG01522 human fibroblasts that were exposed to radiation of different qualities.
abstract: High-resolution multicolour banding FISH (mBAND) and multiplex FISH (mFISH) were used to analyse the aberrations of chromosome 1 in irradiated-AG01522 human primary fibroblasts. The cells were exposed to 1Gy of a panel of radiation of different qualities, such as X-rays, low-energy protons (28keV/μm), helium-ions (62keV/μm) and carbon-ions (96 and 252keV/μm). mBAND and mFISH analysis in calyculin-A G2-condensed chromosome spreads allowed us to detect intra- and interchromosome aberrations involving chromosome 1, including simple and complex-type exchanges, inversions (both para- and pericentric ones), deletions and rings. The data indicate that the induction of chromosomal exchanges was influenced by both Linear energy transfer (LET) and particle types. Moreover, the complex-to-simple exchanges ratio (C-ratio) and interchromosome to intrachromosome exchanges ratio (F-ratio) were evaluated by mFISH and mBAND techniques, respectively. Our results indicate that the C-ratio is a more reliable marker of radiation quality, with values that increased linearly in an LET-dependent manner. In addition, by means of mBAND analysis, the distribution of radiation-induced breakpoints along chromosome 1 was analyzed and compared with the expected distributions of the breaks. The expected values were calculated assuming a random distribution of the breakpoints. The data indicate that, irrespective of the radiation that was used, the breakpoints were non-randomly distributed along chromosome 1. In particular, breaks in the pericentromeric region were encountered at a higher frequency than expected. A deeper analysis revealed that breaks were not located in the constitutive heterochromatin (G-bands 1p11/1q11 and 1q12), but rather in a region comprised between 1p11.2 and 1p22.1, which includes G-light and G-dark bands.
authors.affiliation: Dip di Scienze, Università Roma Tre, Roma, Italy; INFN-Sezione di Roma Tre, Roma, Italy. Electronic address: francesco.berardinelli@uniroma3.it.
authors.forename: F
authors.initials: F
authors.lastname: Berardinelli
authors.affiliation: Dip di Scienze, Università Roma Tre, Roma, Italy.
authors.forename: M
authors.initials: M
authors.lastname: De Vitis
authors.affiliation: Dip di Scienze, Università Roma Tre, Roma, Italy; INFN-Sezione di Roma Tre, Roma, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Nieri
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), Legnaro (Padova), Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cherubini
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), Legnaro (Padova), Italy.
authors.forename: V
authors.initials: V
authors.lastname: De Nadal
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), Legnaro (Padova), Italy.
authors.forename: S
authors.initials: S
authors.lastname: Gerardi
authors.affiliation: Dip di Scienze, Università Roma Tre, Roma, Italy; INFN-Sezione di Roma Tre, Roma, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Tanzarella
authors.affiliation: Dip di Scienze, Università Roma Tre, Roma, Italy; INFN-Sezione di Roma Tre, Roma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Sgura
authors.affiliation: Dip di Scienze, Università Roma Tre, Roma, Italy; INFN-Sezione di Roma Tre, Roma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Antoccia
mesh_terms: D002244:Carbon; D002460:Cell Line; D002869:Chromosome Aberrations; D002871:Chromosome Banding / Q000379:methods*; D056905:Chromosome Breakpoints; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics / Q000528:radiation effects*; D005347:Fibroblasts / Q000528:radiation effects*; D020450:Heavy Ions; D006371:Helium; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D018499:Linear Energy Transfer; D011522:Protons; D014965:X-Rays
chemical_list: D011522:Protons; D006371:Helium; D002244:Carbon
keywords: Carbon ions; Helium-4 ions; Human primary fibroblasts; Ionising radiations; Low-energy protons; Mband; Mfish