中文摘要：

目的探讨吉西他滨对肝癌HepG2细胞辐射增敏作用的影响及机制的初步研究。方法采用克隆形成实验计算不同剂量照射后L-Q模型放射生物学参数比和放射增敏比;应用流式细胞技术检测Gemcitabine（GEM）和辐射前后细胞周期及凋亡率的变化。结果经GEM处理后的HepG2细胞组,Survival fraction at 2 Gy（SF2）较未处理组显著偏低,α值显著增高,GEM处理后增加了辐射诱导的G0/G1期细胞阻滞和细胞凋亡。结论 GEM可显著增强HepG2细胞的辐射敏感性,这种作用是通过增强辐射诱导的G0/G1期细胞阻滞和细胞凋亡来实现的。

英文摘要：

Objective To evaluate the effect of gemcitabine in enhancing the radiosensitivity of hepatoma cell line HepG2 and explore its mechanisms.Methods Clonogenic survival assay is employed to calculate the ratios of L-Q model radiation biology parameters and radiosensitization after different doses of irradiation.Flow cytometry was used to detect the changes in HepG2 cell cycle and apoptosis rate after gemcitabine treatment and radiation exposure.Results The survival fraction at 2 Gy of HepG2 cells treated with gemcitabine was significantly lower,and the value of α was significantly higher than those of untreated cells.GEM treatment increased the percentage of radiation-induced G0/G1 phase cells and cell apoptosis.Conclusion Gemcitabine can significantly enhance the radiosensitivity of HepG2 cells by enhancing radiation-induced cell cycle arrest in G0/G1 phase and cell apoptosis.