Effects of SKP2 on the bystander effect induced by irradiated esophageal cancer cells / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the effect of SKP2 expression on radiation induced bystander effect (RIBE) of esophageal cancer cells.Methods The esophageal cancer cell lines with different SKP2 levels were applied for the study and the SKP2 expression was identified by Western blot.Micronuclei (MN) assay and DNA foci assay were used to evaluate the effect of SKP2 on RIBE.The cells were transfected with SKP2 gene or SKP2 siRNA to further verify the effect of SKP2 on RIBE.Results MN assay showed that the bystander effect induced by the cells with a high level of SKP2 was lower than that induced by the cells with a lower level of SKP2 (t =8.06,P ＜ 0.01).These results were further confirmed by the gene transfection experiments.When the expression of SKP2 was increased,RIBE was decreased (t=11.12,10.16,P ＜ 0.01).Contrarily,when the expression of SKP2 was reduced,RIBE was increased (t =8.39,8.83,P ＜ 0.01).γ-H2AX foci formation assay disclosed that when SKP2 expression in the irradiated cells increased,the repair ability of DNA damage in the bystander cells was higher than the control (t =6.85,7.10,P ＜ 0.01).With the expression of SKP2 decreased,the repair ability of DNA damage was lower than the control (t =7.66,8.47,P ＜ 0.01).Conclusions Over-expression of SKP2 inhibits RIBE of esophageal cancer cells,at least partly through regulating DNA damage repair ability.