A cytogenetic analysis of the long-term effect of uranium mining on peripheral lymphocytes using the micronucleus-centromere assay.
OBJECTIVE
To assess the long-term effect of radiation exposure of uranium miners on a cytogenetic endpoint: micronuclei (Mn) with and without a centromere.


METHODS
Mn were scored using the cytochalasin-B technique. It is known that Mn can comprise acentric fragments or/and whole chromosomes. Mn containing whole chromosomes were identified by means of fluorescence in situ hybridization (FISH) with a centromere-specific probe. The frequency and percentage of Mn were analysed with centromeres (MnC+) in lymphocytes of healthy donors and uranium miners with large radiation exposures several decades ago employed by the Wismut AG in the former German Democratic Republic. The miners were subdivided into those with and those without bronchial carcinoma.


RESULTS
It was shown previously that the relative frequency of MnC+ decreased with dose; this means that the number of Mn originating from acentric fragments increases. In the study presented here, no statistically significant difference in the overall Mn frequency was seen between the analysed groups. The fraction of MnC+, however, was highest in lymphocytes of healthy male donors (mean: 74.6%) followed by healthy miners (mean: 62.1%) and those suffering from cancer (mean: 55.8%).


CONCLUSIONS
The results indicate the occurrence of a genomic instability in lymphocytes of miners, especially those with cancer. It appears that the low percentage of MnC+ may be a marker of genomic instability and cancer predisposition.
Kryscio
A
A
Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, D-45122 Essen, Germany.
Ulrich Müller
W U
WU
Wojcik
A
A
Kotschy
N
N
Grobelny
S
S
Streffer
C
C
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002503:Centromere / Q000235:genetics / Q000528:radiation effects; D020732:Cytogenetic Analysis; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics; D008214:Lymphocytes / Q000187:drug effects / Q000528:radiation effects*; D008297:Male; D015162:Micronucleus Tests; D008875:Middle Aged; D008906:Mining; D016273:Occupational Exposure; D014501:Uranium / Q000633:toxicity*
D014501:Uranium