Antioxidant ability and radiosensitivity in malignant transformed human bronchial epithelial cell line BEP2D induced by α-particle irradiation / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the antioxidant ability and radiosensitivity in the malignant transformed human bronchial epithelial cell line BEP2D induced by α-particle exposure.Methods Glutathione Peroxidase (GPX),Catalase (CAT) and Glutathione (GSH) assay kits were employed to detect GPX and CAT enzyme abilities and the levels of GSH in BEP2D,RH21 ( passage 21 of α-particle-irradiated BEP2D cells),and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from cells of passage 35 of α-particle-irradiated BEP2D cells).MTT assay were used to test the growth rate of BEP2D,RH21 and BERP35T-1 cells treated with 0,30,60,90,120,and 150 μmoL/L H2O2.Colony-forming test and MTT assay were used to examine the cell survival fraction and the growth rate of BEP2D,RH21 and BERP35T-1 cells exposed to 0,2,4,and 8 Gy of γ-rays,respectively.Results GPX and CAT enzyme activities in RH21 and BERP35T-1 cells were obviously lower than in BEP2D( t = 5.75-67.92 ,P ＜ 0.05 ).CAT enzyme activity in BERP35T-1 was lower than that in RH21 cells (t =22.25 ,P ＜0.01 ).Compared to BEP2D cells,decreased level of GSH was detected in BERP35T-1 cells(t = 7.76,P ＜ 0.05 ),but there was no change in RH21.After treatment with 30,60,90,120,and 150 μmol/L H2O2,the growth rates of BEP2D were all higher than those of BERP35T-1 cells(t = 10.37-58.36,P ＜0.01 ).Meanwhile,the growth rates of BEP2D were all higher than those of RH21 cells after treatment with 60,90,120,and 150 μ mol/L H2O2 (t = 29.90-84.68,P ＜ 0.01 ).In addition,compared to BEP2D cells,decreased cell survival fraction and growth rate of BERP35T-1 cells were observed after irradiation with 2,4,and 8 Gy of y-rays ( t = 5.87-34.17,P ＜ 0.05 ).The cell survival fraction and growth rate of RH21 were all lower than those of BEP2D cells at 4 and 8 Gy post-irradition( t =6.33- 45.00,P ＜ 0.05 ).Conclusion The function of antioxidant system decreased in the α-particleinduced transformed cells,which could contribute to the acceleration of cellular malignant transforming process and radiosensitivity.