The regional genomic instability induced by 60Co γ-rays in B16 cells transfected by GFP / 中华放射医学与防护杂志

ABSTRACT

Objective To detect the regional genomic instability of B16 cells treated with 60Co γ-rays by a green fluorescence protein (GFP)-based genomic instability reporting system.Methods Three groups were employed as non-transfection group,vector control group and transfection group.The GFP-marked reporter construct pCMV-EGFP2XhoI for regional genomic instability was successfully transfected into B16 cells using liposome.B16 cells were selected by screening of G418 with a series of concentrations and limiting dilution cultures to yield a single colony.B16 cells with the genomic instability report system were then irradiated by 60Co γ-rays at doses of 0,2 and 4 Gy.The regional genomic instability of B16 cellswas quantified by counting the number of cells with GFP expression.Results B-16 cell strain steadilyexpressing the GFP-based genomic instability reporting system was established successfully.GFP-positiveB16 cells were observed at 1 d after irradiation with 60Co γ-rays at doses of 2 and 4 Gy.Positive correlations between fluorescence intensity and dose and fluorescence intensity and time were also observed.The positive expression rate of GFP followed the increased of dose (F =36.55,36.76,P ＜ 0.05) and time (t =-3.27,-3.16,-4.26,-6.11,-7.17,P ＜ 0.05),and differences between groups were significant.The positive expression rate of GFP increased significantly at 3 d,and maximum expression was observed at 5 d(2.46 ± 0.24 and 3.82 ± 0.35).The level was tending towards stability.Spontaneous GFP expression at a ratio of 1/600 000 was observed in 0 Gy group after 2 weeks of culture.Conclusions The regional genomic instability of B16 cells induced by 60Co γ-rays can be detected using a GFP-labelled genomic instability reporter system.