【摘要】 目的:探讨拓扑替康(TPT)对人肺腺癌细胞的放射增敏作用及机制。方法: 用克隆形成试验检测TPT对人肺腺癌细胞放射效应的影响;用流式细胞技术检测TPT联合放射线作用后人肺腺癌细胞的周期分布。结果:按照多靶单击模型拟合单纯照射组及加药照射组的细胞放射存活曲线,两组的D0、Dq 及N 值分别为1. 605、1 .734 和2 .946;1 .340、0. 587 和1.550。放射增敏比(SERD0)为1 .2。流式细胞仪分析显示,单纯照射组的S期细胞比例较空白对照组明显增高,加药照射组细胞S期堆积被消除。结论:TPT对人肺腺癌细胞具有放射增敏作用。其机制与TPT抑制人肺腺癌细胞放射损伤的修复并杀伤对放射线不敏感的S期细胞有关。更多还原

【Abstract】 OBJECTIVE: To investigate radiosensitizing effect and mechanism of topotecan （TPT） in human lung adenocarcinoma cell line.METHODS:Radiosensitizing effect was studied by clone forming assays. Cell cycle was analyzed by flow cytometry in the radiation group and the radiation combined TPT group.RESULTS:Cells radiation survival curves were plotted according to single-hit-multi-target model for the radiation group and the radiation combined TPT group. D₀, D_q, and N value were 1.605, 1.734, 2.946 and 1.340, 0.587,1.550, respectively. SERD₀ was 1.2. The number of S-phase cells in the radiation group were higher than that in the control, and elimination of S-phase accumulation appeared in the group with drug application.CONCLUSIONS: TPT has obvious radiosensitizing effect on human lung adenocarcinoma cell line. TPT inhibits repair of radiation damage. TPT is effective in killing cells in S-phase that are highly resistant to ionizing radiation.更多还原