【摘要】 目的通过观察甲基磺酸甲酯(MMS)对人胚肺成纤维细胞(HLF)DNA损伤、微核形成及细胞周期改变情况,进一步提示MMS的遗传毒性。方法分别设空白对照组、溶剂对照组和5个MMS染毒组(1.0,2.0,4.0,8.0,16.0μmol/L),共2份,对HLF细胞染毒36 h后,1份直接用彗星试验检测DNA损伤,另一份继续培养24 h后进行微核试验及观察细胞周期改变情况。结果微核试验结果表明,各剂量组的微核率分别为2.0‰,2.0‰,4.0‰,5.5‰,9.0‰,10.5‰,21.0‰,核异常率分别为4.5‰,5.5‰,6.0‰,7.5‰、8.5‰,10.0‰,23.5‰,与空白对照组比较,染毒剂量大于4.0μmol/L的各组差异均有显著性(P<0.05)。各剂量组细胞DNA拖尾率分别为11%,13%,27%,39%,51%,73%,89%,彗星尾长分别为(6.17±1.14),(6.36±1.97),(23.27±3.56),(29.15±4.70),(36.22±7.05),(41.76±6.19),(57.34±9.13)μm。相关分析表明,微核率、核异常率、拖尾率和彗星尾长与染毒剂量间存在明显的剂量-效应关系,其中2.0,4.0,8.0,16.0μmol/L剂量组的微核率、核异常率、拖尾率和彗星尾长明显增加(P<0.05);且随着MMS剂量的升高,高度、重度DNA损伤的比例也逐渐增加。MMS染毒后,随着染毒剂量的增加,HLF细胞逐渐出现G1期阻滞,G2期细胞数增加。结论MMS可致HLF细胞DNA损伤、细胞微核形成增加及细胞周期改变。更多还原

【Abstract】 Objective To observe effects of methyl methylsulfonate（MMS）on DNA damage,micronucleus formation and changes of cell cycle in human embryo lung fibroblast（HLF）cell for further revealing genotoxicity of MMS.Methods Two sets were prepared.Each set composed of one control group,one solvent control group,and 5 MMS exposed groups（1.0,2.0,4.0,8.0,16.0 μmol/L）.After HLF cells exposed to various dosages of MMS for 36 hours,one set was subject to DNA damage test directly by comet assay.The other set continued to be cultured for 24 hours for micronucleus test and observing changes in cell cycle.Results Micronucleus test showed that rates of micronucleus for different dosage groups were 2.0‰,2.0‰,4.0‰,5.5‰,9.0‰,10.5‰ and 21.0‰,and abnormal rates were 4.5‰,5.5‰,6.0‰,7.5‰,8.5‰,10.0‰ and 23.5‰ respectively.Comparing with the control group,the differences of those exposed to dosages >（4.0 μmol/L） were all significant（P<0.05）.In all exposed groups percentages of tailed cells were 11%,13%,27%,39%,51%,73% and 89% respectively.The length of comet tail were（6.17±1.14）,（6.36±1.97）,（23.27±3.56）,（29.15±4.70）,（36.22±7.05）,（41.76±6.19）and（57.34±9.13）μm respectively.Correlation analysis showed that there was a dose-response relationship in-between the dosages exposed and micronucleus rates,abnormal nuclei,percentages of tailed cells and lengths of their comet tail in cells,among them those of 2.0,4.0,8.0,16.0 μmol/L groups increased significantly（P<0.05）.Moreover,as the MMS dosages increased,the ratio of highly severe DNA damages also gradually increased.Along with the increase of MMS dosages,HLF cells gradually appeared G₁ phase arrest and increase of G₂ phase cells.Conclusions It suggests that DNA damage,increase of micronucleus formation and changes of cell cycle of HLF might be induced by MMS exposure.更多还原