SKP2表达对受照食管癌细胞诱导辐射旁效应的影响

Effects of SKP2 on the bystander effect induced by irradiated esophageal cancer cells

目的 探究SKP2表达水平对受照食管癌细胞所诱导辐射旁效应的影响.方法 Western blot法筛选出SKP2高表达和低表达的食管癌细胞系,微核检测法探讨SKP2对受照食管癌细胞所诱导辐射旁效应的影响.建立SKP2高表达和低表达的转染细胞系,Western blot法验证转染效率,微核检测法进一步验证SKP2对受照食管癌细胞所诱导辐射旁效应的影响.通过γ-H2AX聚集点检测法探究SKP2影响受照食管癌细胞所诱导辐射旁效应的作用机制.结果 微核检测结果表明,SKP2高表达的受照细胞诱导的辐射旁效应显著低于SKP2低表达的受照细胞诱导的辐射旁效应（t =8.06,P＜0.01）.SKP2转染细胞系的微核检测结果进一步验证了SKP2的表达对受照食管癌细胞诱导的辐射旁效应的抑制作用,SKP2表达升高,辐射旁效应减弱（t=11.12、10.16,P＜0.01）;SKP2表达降低,辐射旁效应增强（=8.39、8.83,P＜0.01）.γ-H2AX聚集点检测结果表明,受照细胞SKP2表达升高可提高旁效应细胞的DNA损伤修复能力（=6.85、7.10,P＜0.01）.反之,会抑制旁效应细胞的DNA损伤修复能力（=7.66、8.47,P＜0.01）.结论 SKP2的表达抑制受照食管癌细胞诱导的辐射旁效应,并且这一机制至少部分是通过SKP2对DNA损伤修复能力的调节来实现的.

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.