【摘要】 目的　观察中国仓鼠肺细胞 (CHL)在经化学致癌物恶性转化后的染色体不稳定性、有丝分裂关卡功能和对秋水仙素细胞毒性的抗性。方法　CHL细胞在经甲基硝基亚硝基胍 (MNNG)恶性转化后 ,进行核型分析 ,以秋水仙素诱导细胞停滞于有丝分裂中期的比例反映有丝分裂关卡功能 ,MTT法检测秋水仙素的细胞毒性。结果　细胞经 2 μg mlMNNG处理 2 4h ,3周后出现明显的形态转化 ,而且软琼脂集落形成率 ( 5 4 2 %)明显高于对照细胞 ( 10 %) ,表明处理细胞已恶性转化 ;核型分析显示转化细胞的染色体数目在 14～ 48之间 ,只有 7%的细胞有 2 5条染色体 ;而对照细胞 81%有 2 5条染色体 ,表明转化细胞染色体 (数目 )不稳定性 ;以 0 5 μg ml秋水仙素处理转化和对照CHL细胞不同时间 ,计数细胞有丝分裂中期相细胞比例 ,可见在各时间点 ,转化细胞的中期相细胞比例都低于相应的对照细胞 ,这表明转化细胞的有丝分裂关卡功能下降 ;以不同浓度秋山仙素处理转化和对照细胞 2 4h ,可见各浓度组转化细胞生存率明显高于对照细胞 ,这显示恶性转化细胞具有明显的秋水仙素毒性抗性。结论　有丝分裂关卡功能下降可能在细胞的恶性转化过程中有重要作用。更多还原

【Abstract】 Objective To observe the chromosome instability (ClN), mitotic checkpoint function and the resisance to the colchicine cytotoxicity of transformed Chinese hamster lung cells (CHL). Methods Karyotype analysis was used to evaluate the chromosome stability ofthe transformed CHL cells induced by MNNG and the control CHL cells, The ratio of cells arresting at metaphase induced by colchicimes was determimed to evaluate the mitotic checkpoint function;MTT method was used to test the cytotoxicity of colchicimes. Results At the 3rd week after treating CHL cells with 2 μg/ml MNNG for 24 hours, many transformation foci appeared, and the cloning effciency of transformed cells (54.2%)was higher than that of the control cells (1%)in soft agar.These results showed that the treated cell had been transformed malignantly, Karyotype analysis showed that the number of chromosome in the transformed CHL cells varied from 14 to 48, the cells with 25chromosomes only accoumt for 7%, while 81%in the control CHL cells. These indicated that the transformed CHL cells appeared ClN, After the cells were treated with 0.5 μg/ml colchicines for different time, the ratios of the transformed cells arresting at metaphase were lower than those of the comtrol cells, in addition, after the cells were treated with different doses of colchicine for 24 hours, the transformed cells appeared to be resistant to the cytotoxicity of colchicine. The results suggested that the function of mitotic checkpoint decreased. Conclusion The decreasing of mitotic checkpoint function could play an important role during cell transformation.更多还原