应用脉冲电场凝胶电泳分析X射线诱发人骨肉瘤细胞DNA双链断裂与损伤修复效应

PFGE analysis of DNA double-strand breaks and DNA repair process in human osteosarcoma cells irra-diated by X-rays

目的 研究电离辐射诱发人骨肉瘤肿瘤细胞DNA双链断裂与辐射损伤修复效应 ,观察辐射损伤、损伤修复效应与肿瘤细胞辐射敏感性之间的关系。方法 选用强制均匀电场电泳 ,分别测定经不同剂量X射线照射和相同剂量照射后培养不同时间 ,人骨肉瘤Rho0和 1 4 3 B肿瘤细胞株DNA双链断裂。结果 (1 )X射线诱发人骨肉瘤肿瘤细胞的DNA双链断裂与辐射剂量呈线性正比关系 ;(2 )培养后的人骨肉瘤肿瘤细胞对辐射诱发的DNA双链断裂具有一定修复能力 ;(3)Rho0比 1 4 3 .B细胞株具有更高的辐射敏感性 ;(4)脉冲电场凝胶电泳技术是分析人肿瘤细胞DNA双链断裂的敏感方法。结论 脉冲电场凝胶电泳是分析人肿瘤细胞DNA双链断裂的敏感方法 ;

Objective\ To study the induction of DNA double\|strand breaks (DSBs) in human osteosarcoma cells irradiated by X\|ray,the DNA DSBs repair process and the tumour cell radiosensitivity. Methods Two cell lines of human osteosarcoma,Rho0 and 143.B were used.Initial DNA damage of DSBs by X\|ray irradiation was measured using clamped homogeneous electrical field (CHEF) electrophoresis. Results X\|ray\|induced DNA DSBs of human osteosarcoma cells after CHEF\|electrophoresis increased linearly with the irradiation dose between 0 and 50 Gy.The repair of DNA DSBs in human osteosarcoma cells increased with the post\|irradiation incubation time.In contrast to 14 3B cell line at the same dose point,much more DNA DSBs were induced in Rho0 cell line after X\|ray irradiation. Conclusion CHEF pulsed\|field gel electrophoresis (PEGE) is a sensitive method for the determination of radiation\|induced DNA DSBs in high molecular weight DNA of human osteosarcoma cells.Radiation\|induced DNA DSBs of osteosarcoma increase with the dose in a linear manner.after incubation,both Rho0 cell line and 143.B cell line can repair the DNA DSBs.Between two cell lines of human osteosarcoma,Rho0 and 143.B,Rho0 cell line is more sensitive to ionizing radiation than 143.B line.\;