Aneuploidy in exfoliated buccal cells: mechanisms, methods, and future perspectives.

Aneuploidy and polyploidy have a major impact in congenital and acquired diseases, in particular in cancer development. This mini-review highlights the use of exfoliated buccal cells as a non-invasive tool for monitoring aneuploidy. It offers a mechanistic overview and illustrative diagrams addressing five key areas: (i) the causes of aneuploidy; (ii) cell kinetics and aneuploidy induction in epithelial buccal cells; (iii) the methods for the detection of aneuploidy; (iv) the scientific and medical domains applying aneuploidy detection in exfoliated buccal cells; (v) the knowledge gaps and future research perspectives. Although well validated protocols, automated systems and specific probes allowing discrimination between chromosome aberration, aneuploidy and polyploidy in exfoliated buccal cells are available, large-scale cohort human studies remain lacking. These studies are crucial for evaluating aneuploidy in populations exposed to genotoxic agents or at risk for buccal dysplasia. Future validation and predictivity studies should compare fluorescence in situ hybridization and total DNA content methods such as densitometry or flow cytometry, in exposed individuals and control groups with careful control of confounding factors and adherence to standardized reporting guidelines. In addition, assessment of aneuploidy frequencies in parallel in lymphocytes and exfoliated buccal cells in the same populations would allow to compare their predictive value in both tissues. Moreover, mechanistic studies are also needed to better understand the sources of variability in aneuploidy and how buccal cell biology compares to other cell types. In conclusion, due to their ease of collection and non-invasive nature, exfoliated buccal cells represent a promising tool for aneuploidy testing for risk assessment of environmental or occupational exposures and disease prediction and monitoring.