title: In vivo accumulation of 8-hydroxy-2'-deoxyguanosine in DNA correlates with release of reactive oxygen species in Fanconi's anaemia families.
abstract: The present study was aimed at verifying the occurrence, if any, of in vivo oxidative DNA damage in FA homozygotes, their parents and siblings. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) was measured, by HPLC/EC, in DNA from circulating blood leucocytes from FA homozygotes and their relatives and compared with a group of paediatric and adult healthy subjects. The population studied consisted of: (i) 15 FA homozygotes; (ii) 24 FA heterozygotes; (iii) 11 siblings. The 8-OHdG level in FA homozygotes was significantly higher with respect to age-matched controls, with a mean level of 33.3 +/- 6.8 (mean +/- SE) and 3.9 +/- 0.26 8-OHdG/10(5) dG respectively. The FA parents (heterozygotes) also displayed higher 8-OHdG levels relative to controls. The release of hydroxyl (.OH) and .OH-like radicals from leucocytes was determined by luminol-dependent chemiluminescence (LDCL) in a subgroup of FA homo- and heterozygotes, showing a very large in vivo formation of non-superoxide radicals. Chromosomal instability was also measured in the FA population. When relating either 8-OHdG or LDCL levels to spontaneous or diepoxybutane-induced chromosomal instability (S-CI and DEB-CI respectively), a significant correlation was observed between the 8-OHdG, LDCL and S-CI data. Within families a positive association was found between 8-OHdG levels in homozygotes and their related heterozygotes, suggesting segregation of the genetic defect(s) underlying the abnormal oxidative metabolism. The present study provides evidence for an in vivo pro-oxidant state in FA, in terms of excess formation of .OH and .OH-like radicals, and of DNA hydroxyl adducts. This finding appears to be shared by homozygotes and, to a lesser extent, by heterozygotes.
authors.affiliation: IST, Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Degan
authors.forename: S
authors.initials: S
authors.lastname: Bonassi
authors.forename: M
authors.initials: M
authors.lastname: De Caterina
authors.forename: L G
authors.initials: LG
authors.lastname: Korkina
authors.forename: L
authors.initials: L
authors.lastname: Pinto
authors.forename: F
authors.initials: F
authors.lastname: Scopacasa
authors.forename: A
authors.initials: A
authors.lastname: Zatterale
authors.forename: R
authors.initials: R
authors.lastname: Calzone
authors.forename: G
authors.initials: G
authors.lastname: Pagano
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D002877:Chromosomes, Human; D004247:DNA / Q000097:blood*; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood; D004852:Epoxy Compounds; D005199:Fanconi Anemia / Q000097:blood* / Q000235:genetics*; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008163:Luminescent Measurements; D008165:Luminol; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016897:Respiratory Burst / Q000502:physiology
chemical_list: D004852:Epoxy Compounds; D017382:Reactive Oxygen Species; D008165:Luminol; C007366:diepoxybutane; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D003849:Deoxyguanosine