Study on oxidative lipid and DNA damages in the malignant transformed BEP2D cells induced by α-particle exposure

Objective To investigate the mechanism of malignant transformation in human bronchial epithelial cell line BEP2D exposed to α-particles.Methods The levels of intracellular ROS and malonaldehyde (MDA) in BEP2D,RH22 (passage 22 of α-particle-irradiated BEP2D cells) and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from the passage 35 of α-particle-irradiated BEP2D cells) were assayed with DCFH-DA and MDA kit,respectively.The expressions of 8-OH-dG and γ-H2AX in BEP2D,RH23 (passage 23 of α-particle-irradiated BEP2D cells)and BERP35T-1 cells were also measured with immunocytochemistry and immunofluorescence staining.Results Compared to BEP2D cells,the levels of ROS ( t =4.30 and 3.94,P ＜ 0.05 ) and MDA ( t =4.89 and 15.10,P ＜0.05) increased in RH22 and BERP35T-1 cells.The expressions of 8-OH-dG (t =3.80 and 2.92,P ＜ 0.05 ) and γ-H2AX ( t =7.61 and 12.67,P ＜ 0.05 ) in RH23 and BERP35T-1 cells were also higher than those in BEP2D cells.Conclusions Oxidative stress induces lipid peroxidation and DNA damage leading to genomic instability,which could contribute to cellular malignant transforming process in the human bronchial epithelial cell line BEP2D with α-particle exposure. Key words: Human bronchial epithelial cell line;  α-particle;  Reactive oxygen radicals; Oxidative damages;  Carcinogenesis