照射存活后代的鼻咽癌细胞株放射生物学特性研究

目的　了解鼻咽癌细胞系CNE -2Z具有淋巴道转移倾向的克隆株H 5照射存活后代的放射敏感性和体内、体外细胞生长特性。方法　采用克隆形成率检测H 5及照射存活后代 2组癌细胞的放射敏感性 ;体外细胞增殖实验结晶紫染色法检测体外细胞增殖能力 ;用瘤细胞裸鼠体内移植观察 2组细胞的体内增殖、转移能力。结果　H5细胞照射存活后代的放射敏感性比未处理的H5细胞低 ,处理前 2Gy存活率 (SF2 )为 0 .3 0 ,平均致死剂量 (D0 )为 1.93Gy ,处理后细胞的SF2为 0 .49,D0 为 2 .56Gy ;体外细胞增殖减慢 ,有非常显著性差异 (P <0 .0 1) ;体内细胞增殖减慢 ,有显著性差异 (P <0 .0 5) ;成瘤率减小 ,转移率增高 ,体积倍增时间延长 ,但无显著性差异 (P >0 .0 5)。结论　照射存活后代的细胞放射敏感性降低 ,体内、体外细胞增殖减慢。

Radiobiologic Study on Progenys from the Irradiated Nasopharyngeal Carcinoma (NPC) Subline Possessing the Potentiality of Lymphoid Metastasis

Objective To investigate the change of radiosensitivity and growth characteristics in vitro,in vivo of the progeny from the irradiated NPC subline possessing the potentiality of lymphoid metastasis.Methods Radiosensitivity of H5 cell line treated and untreated with radiation was measured by clongenic assay,proliferation ability was investigated by crystal violet staining.To study the change of growth characteristics in vivo of treated cells,tumor cells were transplanted into nude mice in this experiment.Results The progeny of survival cells of H5 clone showed radioresistance as compared with untreated H5 cells,the survival fraction of 2 Gy(SF2) were 0.49 and 0.30 respectively,and the average death dose(D 0) were 2.56 Gy and 1.93 Gy respectively;The growth rate of H5 cells in vitro and in vivo was significantly suppressed after treated with radiation( P <0.05);the incidence of metastasis of the progeny of survival H5 cells was slightly enhanced( P >0.05).Conclusion The progenys of survival cells of radiation show radioresistance and suppressed proliferation ability not only in vitro,also in vivo.