A cell co-culture model for studying bystander effect and its application on bystander DNA double-strand breaks induced by alpha-particles irradiation / 中华放射医学与防护杂志

ABSTRACT

Objective To establish an experimental model for the study of α-particle-induced bystander effect of DNA damage and investigate the characteristics of bystander DNA double-strand break (DSB).Methods The red fluorescence fusion protein of HsBrkl-RFP was used to mark the cytoplasm of one cell line to distinguish the irradiated target cells (HFS-RFP) and the non-irradiated bystander cells (HFS) in the co-culture cellular model.After α-particle irradiation,cellular DSB and its repair kinetics were analyzed by the immunofluorescence staining of γH2AX and laser confocal microscope observation.Results A bystander studying model was established by co-culturing human HFS-RFP cells with its partner HSF cells.After 0.1 Gy or 0.2 Gy α-particle irradiation,the similar kinetics of γH2AX foci production and abatement were observed in both irradiated HFS-RFP cells and non-irradiated bystander HFS cells,in which the highest level of γH2AX foci was detected at 1 h post-irradiation.The second peak of γH2AX foci formation appeared at 8 h post-irradiation,which possibly indicates the occurrence of secondary DSB.However,the production of secondary DSB in the bystander cells was weaker than that in the irradiated cells.Conclusions The cell co-culture model can be used for bystander effect investigation.Bystander DSB can be effectively induce by irradiation and the secondary breakage of DNA DSB in the bystander cells may relative to the consequential biochemical processing of clustered DNA damage.