The micronucleus assay in human buccal cells as a tool for biomonitoring DNA damage: The HUMN project perspective on current status and knowledge gaps

Exposure of thermoelectric power-plant workers to volatile organic compounds from fuel oil: Genotoxic and cytotoxic effects in buccal epithelial cells

“…Bio-monitoring the effect of exposure to genotoxic substances in the workplace is essential for the development of strategies to improve occupational health and safety conditions [9]. Human bio-monitoring may be done with various cytogenetic tests that evaluate genotoxic effects by detecting DNA damage, such as sister chromatid exchange and micronuclei [10,11]. Micronuclei in exfoliated buccal epithelial cells emerge during mitosis of the basal layers of the epithelium as extra-chromosomal DNA particles, when chromosome fragments or whole chromosomes lag behind and fail to be included in the main nuclei of the daughter cells, as a result of a clastogenic or aneugenic events [11,12].…”

“…Human bio-monitoring may be done with various cytogenetic tests that evaluate genotoxic effects by detecting DNA damage, such as sister chromatid exchange and micronuclei [10,11]. Micronuclei in exfoliated buccal epithelial cells emerge during mitosis of the basal layers of the epithelium as extra-chromosomal DNA particles, when chromosome fragments or whole chromosomes lag behind and fail to be included in the main nuclei of the daughter cells, as a result of a clastogenic or aneugenic events [11,12]. Micronuclei in epithelial cells reflect genotoxic events occurring in the dividing basal cell layer of the putative target organ 1-3 weeks earlier [13,14], which allows for cytogenetic surveillance of groups at high risk of developing organ-specific cancer (e.g., upper aerodigestive tract) or oral premalignant lesions [15][16][17].…”

“…Micronuclei in epithelial cells reflect genotoxic events occurring in the dividing basal cell layer of the putative target organ 1-3 weeks earlier [13,14], which allows for cytogenetic surveillance of groups at high risk of developing organ-specific cancer (e.g., upper aerodigestive tract) or oral premalignant lesions [15][16][17]. Chromosomal damage in epithelial cells also leads to nuclear anomalies other than micronuclei, such as karyorrhexis, karyolysis, pyknosis, condensed chromatin, 'broken eggs' and bi-nucleated cells [11,18]. Karyorrhexis, karyolysis and pyknosis are associated with both cytotoxicity (necrosis and keratinization) and genotoxicity (apoptosis) accompanying the early stages of apoptosis [12,14], and thus are also considered effective Table 1 Age and main lifestyle habits of the groups exposed (power-plant workers) and non-exposed (administrative workers) to VOCs [data are reported as the number of subjects (% between brackets)]; VOCs concentration (mean ± SD) from both working areas (thermoelectric power-plant facilities and offices of administrative services).…”

“…biomarkers for populations exposed to mutagenic and carcinogenic agents [19]. According to Holland et al [11], the observation of both micronuclei and these other nuclear anomalies provides a more comprehensive assessment of chromosomal damage than is the case from micronuclei only, particularly when cytotoxic effects are also considered. The micronucleus assay with exfoliated cells is emerging as a preferential method to measure this type of damage [11]; it is considered a sensitive and non-invasive method for monitoring DNA damage in human populations [15,20].…”

“…According to Holland et al [11], the observation of both micronuclei and these other nuclear anomalies provides a more comprehensive assessment of chromosomal damage than is the case from micronuclei only, particularly when cytotoxic effects are also considered. The micronucleus assay with exfoliated cells is emerging as a preferential method to measure this type of damage [11]; it is considered a sensitive and non-invasive method for monitoring DNA damage in human populations [15,20]. Recently, such approaches have been frequently used in bio-monitoring studies of occupational exposure to carcinogenic substances [e.g., [21][22][23][24][25], but to our knowledge no study has been done for thermoelectric power-plant workers exposed to VOCs derived from fuel oil.…”