反复照射建立食管癌放射抗性细胞系方法的重复性和稳定性研究

摘要

Objective To study the repeatability and stability of repeated irradiation method to establish the radioresistant esophageal cancer cell line and to observe the variation of radiosensitivity between the radioresistant cell line and its parental cell line.Methods A radioresistant cell line,TE13R120,was established from a human esophageal squamous cancer cell line TE13 by repeated irradiation,120 Gy in total dose.Colony formation assay was used to calculate the radiation biology parameters and detect radiation resistance.Besides,multi-target single-hit model was adopted to fit dose-survival curve of TE13 and TE13R120 cell.The cells were cultrured for 8 d,the cell growth curve was drawn to calculate the population doubling time of TE13 and TE13R120 cell.Results After radiation by 120 Gy in total dose,TE13R120 cell line showed significant radioresistance compared with its parental cells TE13.The D0 ,Dq,and N of TE13R120 showed siguificant radioresitance as compared with those of TE13(2.36,2.17,2.50 vs 1.90,1.11,1.80),but SF2 ,a/β were lover in the former cell line(0.53,2.67 vs 0.73,8.00).The population doubling time of TE13R120 was 20.70 h,longer than its parental cell line TE13 (17.67 h).The results were similar with those of the first establish line.Conclusion The radioresistant cell line established by repeated radiation exposures and gradually screening is reliable since it can build a stable cell line with radioresistant phenotype.%目的：探讨射线反复照射方法建立食管癌放射抗性细胞系的重复性及稳定性，并观察辐射抗性细胞与其亲代细胞之间的放射敏感性的差异。方法应用射线对人食管鳞状细胞癌细胞 TE13进行反复照射，累计剂量120 Gy，建立具有放射抗性的细胞系 TE13R120。采用细胞克隆形成实验测定2种细胞的放射生物学参数，检测其辐射抗性，采用单击多靶模型拟合存活曲线。经连续8 d培养细胞，绘制2种细胞的生长曲线并用 Logrank 检验计算群体倍增时间。比较此次实验结果与初次建系时结果的相似性。结果接受120 Gy 总剂量照射后，TE13R120较 TE13表现出明显的放射抗性，TE13R120的放射生物学参数 D0、Dq、N 均高于 TE13（2．36、2．17、2．50 vs 1．90、1．11、1．80），SF2、α／β均低于 TE13（0．53、2．67 vs 0．73、8．00）。TE13R120的细胞群体倍增时间为20．70 h，长于亲代TE13（17．67 h）。该结果与此前初次建系时结果相似。结论应用射线反复照射并逐步筛选建立辐射抗性细胞系的方法可靠，能建立具有稳定辐射抗性表型的细胞系。