UCN-01提高肺腺癌细胞放射敏感性的实验观察

Potentiation of radiosensitivity by 7-hydroxystaurosporine (UCN-01) in a pulmonary adenocarcinoma cell line

目的 观察p53基因突变的人肺腺癌细胞系 973照射后G2 期阻滞以及药物 7 Hydroxys taurosporine(UCN 0 1 )是否能去除此阻滞并增加放射敏感性 ,探讨UCN 0 1增加放射敏感性的机制。方法 用细胞培养和流式细胞仪技术分析X射线照射对 973细胞周期 (特别是G2 期阻滞 )的影响 ,观察UCN 0 1对放射引起的G2 期阻滞的影响。应用细胞克隆形成实验观察UCN 0 1对放射敏感性的影响。结果 照射明显导致 973细胞G2 期阻滞 ,未照射组 (对照组 )及 2、4和 6Gy组的G2 期比例分别为 1 4 .8%、42 .8%、55 .9%和 60 .5 % ,G2 期阻滞的程度与照射剂量呈正相关。UCN 0 1能够去除放射引起的973细胞G2 期阻滞 ,50、1 0 0、2 0 0和 40 0nmol/LUCN 0 1组G2 期比例由对照组的 35 .4%分别降至 2 3 .5 %、1 9.6 %、1 6 .3 %和 1 2 .4% ,UCN 0 1去除G2 期阻滞的程度与药物浓度呈正相关。UCN 0 1能明显降低放射后 973细胞的存活分数 ,2 0 0和 40 0nmol/LUCN 0 1组的放射增敏比分别为 1 .1 3和 1 .31。结论 UCN 0 1对 973细胞有放射增敏作用 ,机制可能与UCN 0 1去除放射引起的G2 期阻滞有关。

Objective To investigate the radiosensitization of 7 hydroxystaurosporine (UCN 01) by its abrogation of radiation induced G 2 arrest. Methods Flow cytometry was used to observe the cell cycle effect of X ray irradiation and UCN 01 on human pulmonary adenocarcinoma cells (973) with mutated p53. The effect of radiosensitivity was determined by clonogenic assay and was quantified by calculating the sensitive enhancement ratio (SER). Results Irradiation resulted in G 2 arrest in a dose dependent manner. The proportion of cells in G 2 phase increased from 14.8% in the control group to 42.8%, 55.9% and 60.5% 12 hour after irradiation of 2, 4 and 6 ?Gy respectively. Radiation induced G 2 arrest was abrogated by UCN 01 in a concentration dependent manner. UCN 01 at the concentrations of 50, 100, 200 and 400?nmol/L decreased the proportion of cells in G 2 phase of 35.4% in the control group to 23.5%, 19.6%, 16.3% and 12.4%, respectively. UCN 01 resulted in a radiosensitization in 973 cells. SER was 1.13 and 1.31 respectively for 200 ?nmol/L and 400?nmol/L UCN 01. Conclusion Radiosensitization of UCN 01 in 973 cells characterized by mutated p53 is associated with its abrogation of radiation induced G 2 arrest.