氢醌染毒HL-60细胞DNA损伤模型构建及其与DNA-PKCS表达之间的关系

Construction of DNA damage model in HL-60 cell line through hydroquinone exposure and its correlation with DNA-PKCSexpression

目的探讨DNA-PKCS在氢醌致人急性粒细胞白血病HL-60细胞DNA双链断裂损伤修复中作用。方法采用不同剂量氢醌在不同时间范围内诱导HL-60细胞，应用荧光显微镜检测HQ处理各个阶段γ-H2AX焦点的形成。利用Real Time-PCR、免疫荧光染色等分子生物学技术，研究DNA-PKCS基因在转录和翻译水平的表达。结果染毒后18h组和24h组，50um和100um HQ组γ-H2AX焦点的数目随氢醌浓度的递增而明显增加，但两者相比无明显差异。染毒后18h组和24h组，HL-60细胞内DNA-PKCS转录表达水平与蛋白表达水平诱导氢醌浓度之间存在明显的时间剂量依赖关系。结论50um和100um的氢醌18h和24h处理可以诱导HL-60细胞内明显的DNA双链断裂损伤，且损伤程度与DNA-PKCS表达水平直接相关。

Objective To study the correlation of DNA--PKCS expression with DNA double strand breaks （DSBs） in HL-60 DNA damage model induced by hydroquinone. Methods HL-60 cells were induced with 10um, 25um, 50um and 100um HQ for 6 hours, 18 hours, and 24 hours to create DSBs. γ-H2AX foci formation was observed through a fluorescence microscope on each stage of HQ given. Real time-PCR and immunostaining assay were applied to explore the expression of DNA-PKcs in HL-60 cell line in both transcriptional and translation level. Results After 18-hour and 24-hour exposures with 50um and 100um HQ individually, a significantly higher expression ofγ-H2AX foci was observed in HL-60 cells, but revealed no significant difference between the expression of γ-H2AX loci and HQ concentration. After 18-hour and 24-hour exposure with 10um, 25um, 50um, and 100um HQ, a significant higher expression of DNA-PKcs was observed in both transcription and the translation level which demonstrated a significant difference between the expression of DNA-PKes and HQ concentration. Conclusion Significant DNA double strand breaks could be induced by 18-hour and 24-hour exposure with 50um and 100um HQ, and the damage level was directly correlated with the expression of DNA-PKcs.