健择对人鼻咽癌细胞系放射增敏机制的实验研究

Empirical Studies on Gemcitabine as a Mechanism of Radiosensitization in Human Nasopharyngeal Carcinoma Cell Line

目的:观察单纯放射及放射联合健择(gemcitabine)对人鼻咽癌细胞系(CNE-2)细胞周期改变的影响,探讨健择对CNE-2细胞的放射增敏机制。方法:用流式细胞仪技术分析60Coγ射线单纯照射和照射联合健择对CNE-2细胞周期的影响。结果:单纯照射导致CNE-2细胞G1期阻滞,照射剂量<6Gy时与照射剂量呈正相关,>6Gy时G1期阻滞基本稳定在一定水平。5mg/L、10mg/L、15mg/L健择与CNE-2细胞共育24h后照射2Gy,以S期阻滞为主;随着单次照射剂量的提高,以G1阻滞明显。CNE-2细胞与健择15mg/L共育12h后照射2Gy,开始时以G1阻滞为主,但24h后以S期阻滞明显,且至少维持36h以上。结论:健择对CNE-2细胞有中度放射增敏作用;其机制可能与健择引起S期或G1期阻滞有关。

Objective： To analyze the radiosensitization effect of gemcitabine in human nasopharyngeal carcinoma cell line CNE-2 in vitro. Methods： Flow cytometry was used to observe the effect on cell-cycle of γ-irradiation in conjunction with gemcitabine on CNE-2 cells. Results： Irradiation resulted in G1 block in a dose-dependent （〈6 Gy） manner. Concentrations of 5 mg/L, 10mg/L, or 15 mg/L gemcitabine were incubated with CNE-2 cells for 24h prior to irradiation with 2 Gy, resulting in significant S-phase block. G1 block was observed following increased doses of irradiation. 15nmol/L gemcitabine was incubated with CNE-2 for 12h prior to 2 Gy irradiation, resulting in an immediate G1 block that switched to an S-phase block after 24h and that lasted for at least 36 h. Conclusion： Radiosensitization of gemcitabine in CNE-2 cells is associated with induction of S-phase and/or G1 block.