Lack of epithelial-to-mesenchymal transition induction in two bronchial epithelial cell lines after alpha and gamma irradiation

The induction of epithelial-to-mesenchymal transition (EMT) in human lung epithelial cell lines was investigated after α-particle and γ-radiation exposures. We applied TGF-β treatment of cells as positive EMT-controls and tested in parallel if radiation has a potentiating effect on the EMT induction. BEAS-2B and HBEC-3KT cells were irradiated with 5.4 MeV α-particles or γ-rays (60Co, 1.13-1.15 Gy/min) with or without of TGF-β. The cells were harvested three days post treatment and the EMT markers vimentin, fibronectin and E-cadherin were analysed by immunofluorescence staining and Western blotting. The TGF-β treatment-induced EMT in both cell lines in the applied concentrations. We could not prove any clear EMT induction with low or moderate doses of α-particles and γ-rays. No significant additive effect with radiation and TGF-β was observed. We suggest that there might be a different mechanism induced by radiation in bronchial cells after radon and medical exposures that does not involve direct EMT changes.