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Longitudinal study on fragile sites expression in floriculturist workers
Abstracts/Mutation Research 360 (1996) 201-300
of DNA-adducts is weakly increased by the amount of total adducts and the percentage of m5dC is not significantly modified. No clear dose-effect relationship was observed in this subgroup. In non-smokers, we have observed an increase with a dose-effect relationship of the number of breaks per cells, the percentage of cells with aberrations excluding gaps and the number of cells with more than 1 break, the number of MN and SCE were not modified. The number and the amount of adducts were strongly increased in exposed workers percentage of m5dC was decreased. DNA-adducts appear to be the best marker for genotoxic risk assessment. Smoke habits are a very confounding factor and the influence of coke oven emission is comparable to cigarette smoke. 4-19
Longitudinal study on fragile sites expression in floriculturist workers A. Musio, I. Sbrana; Dipartimento di Scienze dell'Ambiente e del Territorio, Universith di Pisa, Via S. Giuseppe 22, Pisa, Italy In a previous work we showed that fragile sites (FS) could be a sensitive indicator of occupational exposure to potential mutagenic/carcinogenic chemicals (Sbrana and Musio Cancer Genet Cytogenet, in press). In that paper we analysed the expression of aphidicolin induced common FS in greenhouses floriculturist workers and detected excess of aberration at six cancer breakpoint bands and at four chromosomal bands carrying oncogenes and tumor suppressor genes. In order to verify the reliance of this result, we carried out 1 year later this analysis on the same subjects and with the same experimental conditions. Data showed a decreased frequency of aberrations compared to the first study in all subjects and a lower difference between exposed and control subjects. Nevertheless, a detailed analysis showed that the breakage level was again significantly higher in the exposed subjects at two cancer breakpoint bands 3p14, 7q32 and at the site 13q14 of rb tumor sup-
243
pressor gene. These results confirm the validity of this new approach to the study of the genotoxic effect of chemical exposure. 4-20
Fragile site expression in children from Chernobyl M. Nieri, A. Musio, P. Aretini and I. Sbrana; Dipartimento di Scienze dell'Ambiente e del Territorio, Universith di Pisa, Via S. Giuseppe 22, Pisa, Italy Fragile sites (FS) were thought to be implicated in the chromosomal rearrangements present in malignant disease: this hypothesis, still controversial, was supported by the observation of association between FS localization, cancer breakpoints and genes involved in tumorigenesis. A relationship between FS and cancer is further suggested by the preferential clastogenic action, on these sites, by many mutagens and carcinogens. In this paper, the relationship between FS and cancer has been studied by analysing the expression of aphidicolin-induced common FS in fourteen children exposed to ionising radiations during the Chernobyl nuclear power plant accident. Seven of these children developed tyroid papillary carcinomas, a tumor associated with a rearrangement of the ret protooncogene due to a chromosomal inversion of the long arm of chromosome 10: inv (10) (qll.2 q.21). The other seven children, matched to them for sex and age, were without cancer. Analyses of G-banded metaphases in subjects with cancer showed a frequency of aberrations very high compared with that observed in laboratory control subjects. No aberration was observed in bands 10q 11-10q21. However, an excess of breakage events occurred in all subjects at three chromosomal bands, 3p14, 7q32, 16q22, which are cancer breakpoints for leukemia and lymphoma and at 16q23. These results will be compared to those obtained from children without cancer to identify eventual specific feature of fragility due to radiation exposure or tumor development.
of DNA-adducts is weakly increased by the amount of total adducts and the percentage of m5dC is not significantly modified. No clear dose-effect relationship was observed in this subgroup. In non-smokers, we have observed an increase with a dose-effect relationship of the number of breaks per cells, the percentage of cells with aberrations excluding gaps and the number of cells with more than 1 break, the number of MN and SCE were not modified. The number and the amount of adducts were strongly increased in exposed workers percentage of m5dC was decreased. DNA-adducts appear to be the best marker for genotoxic risk assessment. Smoke habits are a very confounding factor and the influence of coke oven emission is comparable to cigarette smoke. 4-19
Longitudinal study on fragile sites expression in floriculturist workers A. Musio, I. Sbrana; Dipartimento di Scienze dell'Ambiente e del Territorio, Universith di Pisa, Via S. Giuseppe 22, Pisa, Italy In a previous work we showed that fragile sites (FS) could be a sensitive indicator of occupational exposure to potential mutagenic/carcinogenic chemicals (Sbrana and Musio Cancer Genet Cytogenet, in press). In that paper we analysed the expression of aphidicolin induced common FS in greenhouses floriculturist workers and detected excess of aberration at six cancer breakpoint bands and at four chromosomal bands carrying oncogenes and tumor suppressor genes. In order to verify the reliance of this result, we carried out 1 year later this analysis on the same subjects and with the same experimental conditions. Data showed a decreased frequency of aberrations compared to the first study in all subjects and a lower difference between exposed and control subjects. Nevertheless, a detailed analysis showed that the breakage level was again significantly higher in the exposed subjects at two cancer breakpoint bands 3p14, 7q32 and at the site 13q14 of rb tumor sup-
243
pressor gene. These results confirm the validity of this new approach to the study of the genotoxic effect of chemical exposure. 4-20
Fragile site expression in children from Chernobyl M. Nieri, A. Musio, P. Aretini and I. Sbrana; Dipartimento di Scienze dell'Ambiente e del Territorio, Universith di Pisa, Via S. Giuseppe 22, Pisa, Italy Fragile sites (FS) were thought to be implicated in the chromosomal rearrangements present in malignant disease: this hypothesis, still controversial, was supported by the observation of association between FS localization, cancer breakpoints and genes involved in tumorigenesis. A relationship between FS and cancer is further suggested by the preferential clastogenic action, on these sites, by many mutagens and carcinogens. In this paper, the relationship between FS and cancer has been studied by analysing the expression of aphidicolin-induced common FS in fourteen children exposed to ionising radiations during the Chernobyl nuclear power plant accident. Seven of these children developed tyroid papillary carcinomas, a tumor associated with a rearrangement of the ret protooncogene due to a chromosomal inversion of the long arm of chromosome 10: inv (10) (qll.2 q.21). The other seven children, matched to them for sex and age, were without cancer. Analyses of G-banded metaphases in subjects with cancer showed a frequency of aberrations very high compared with that observed in laboratory control subjects. No aberration was observed in bands 10q 11-10q21. However, an excess of breakage events occurred in all subjects at three chromosomal bands, 3p14, 7q32, 16q22, which are cancer breakpoints for leukemia and lymphoma and at 16q23. These results will be compared to those obtained from children without cancer to identify eventual specific feature of fragility due to radiation exposure or tumor development.