Glutaraldehyde (GA) is a high production volume chemical that is very
reactive with a wide spectrum of medical, scientific and industrial
applications. Concerning the genotoxic and carcinogenic effect of GA,
controversial results have been reported, while in humans no studies
with positive carcinogenic results for GA have been published. However,
our previous study concerning the combined effects of exposure to both
GA and ionising radiation (IR) in peripheral blood lymphocytes of
healthy donors has shown that non-genotoxic doses of the chemical
induces a statistically significant increase in chromosomal
radiosensitivity. The lack of information concerning the
radiosensitizing potential of GA on cancerous cells triggered us to test
the radiosensitizing effect of GA on breast cancer cells (MCF7). For
this purpose the G2-chromosomal radiosensitivity assay (G2-assay) was
used. The assay involves G2-phase irradiation and quantitation of the
chromosomal fragility in the subsequent metaphase. The experimental data
show that 48 h exposure to GA, at doses that are not clastogenic to MCF7
breast cancer cells enhances G2-chromosomal radiosensitivity of this
cell line. In an effort to evaluate whether the observed increase in
GAs-induced G2-chromosomal radiosensitization is linked to GA-induced
alterations in the cell cycle and feedback control mechanism, Mitotic
Index analysis was performed. The results have shown that such a
mechanism cannot be directly related to the observed GA-induced increase
in G2-chromosomal radiosensitivity. Since increased G2-chromosomal
radiosensitivity has been linked with cancer proneness, the
radiosensitizing effect of GA at non-clastogenic doses highlights its
potential carcinogenic profile
