The comet assay of nasal epithelia: measurement of DNA damage for the assessment of genotoxic air pollution.
OBJECTIVE
The alkaline single cell gel electrophoresis or "comet" assay allows measurement of DNA damage in single cells with a high degree of sensitivity, e.g., for investigations of the effect of environmental agents with DNA-damaging potential. This study aimed to adapt this test to respiratory cells of the human nasal mucosa to examine the genotoxic effect of air pollution (cigarette smoke).


METHODS
In a prospective study, nasal epithelia of 16 cigarette smokers were examined by the adapted comet assay and the results were correlated with the results of the Papanicolaou-stained nasal cytology, carried out in a blinded fashion. The control group comprised 20 non-smoking men. All subjects under investigation were healthy office workers.


METHODS
Nasal epithelia were harvested from the maxilloturbinates. One part of cells was Papanicolaou stained and evaluated by cytopathologists. The comet assay was performed on the other part of the cells. The examiners were blinded to the study and control groups.


RESULTS
Among cigarette smokers, a significant correlation between cytopathological cell nucleus changes (metaplasia and dysplasia) and the DNA migration (tail lengths) in the comet assay was found as a sign of DNA damage. This was not found in nonsmoking control persons.


CONCLUSIONS
These results confirm the sensitivity of the comet assay and the hypothesis that cell nucleus changes in conventional nasal cytology are associated with DNA damage.
Glück
U
U
Suva, Swiss National Accident Insurance Institute, Division of Occupational Medicine, Kantonsspital Luzern.
Gebbers
J O
JO
D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D020552:Comet Assay / Q000379:methods*; D004247:DNA / Q000032:analysis / Q000187:drug effects*; D004249:DNA Damage; D004847:Epithelial Cells / Q000737:chemistry / Q000187:drug effects / Q000473:pathology; D006801:Humans; D008297:Male; D008679:Metaplasia / Q000139:chemically induced / Q000473:pathology; D008875:Middle Aged; D009153:Mutagens / Q000009:adverse effects*; D009666:Nose / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects; D013194:Staining and Labeling / Q000379:methods
D000393:Air Pollutants; D009153:Mutagens; D004247:DNA