论文部分内容阅读
目的 探讨黑色氧化镍 (Ni2 O3)致癌的机制 ,寻找镍致癌的敏感性、特异性强的监测指标。方法 用单细胞凝胶电泳法观察Ni2 O3对人胚肺细胞DNA的损伤。用甲基化敏感酶酶切、硫酸氢钠盐转化和AP PCR技术观察Ni2 O3恶性转化的人胚肺细胞DNA的CpG岛甲基化水平。用mRNA差异表达的方法观察镍暴露的人胚肺细胞与对照细胞基因表达的差异。结果 黑色氧化镍可以明显造成人胚肺细胞DNA损伤 ,2 0 μg/ml的Ni2 O3染毒组细胞彗星尾长 /彗星总长为 0 .4 87± 0 .195 ,而对照组为 0 .191± 0 .0 72 ,二者差异有显著性 (P <0 .0 1)。经镍恶性转化的人胚肺细胞DNA的CpG岛甲基化水平明显升高 ,而且该细胞与对照细胞间 ,在cDNA指纹图上约 5 0 0bp处存在明显表达差异带Cyclophilin(Cyp)。结论 经Ni2 O3转化的人胚肺细胞Cyp基因片断表达下调。
Objective To investigate the mechanism of carcinogenicity of black nickel oxide (Ni2O3) in order to find the sensitive and specific monitoring indicators of nickel carcinogenesis. Methods Single cell gel electrophoresis was used to observe the DNA damage of human embryonic lung cells by Ni2O3. Methylation-sensitive enzyme digestion, sodium bisulfate salt transformation and AP PCR were used to observe the CpG island methylation level of Ni2O3 malignant transformed human embryonic lung cells. Differential expression of mRNA was used to observe the difference in gene expression between nickel-exposed human embryonic lung cells and control cells. RESULTS: NiO could obviously cause DNA damage in human embryonic lung cells. The length of the comet tail/cometary star in the 20 μg/ml Ni 2 O 3 exposure group was 0.487± 0 .195 compared with 0. 191± in the control group. 0. 0 72, the difference was significant (P < 0.01). The methylation level of CpG island in DNA of human embryonic lung cells transformed with nickel was significantly increased, and between the cells and the control cells, there was a significant difference in the expression of Cyclophilin (Cyp) at about 500 bp on the cDNA fingerprint. Conclusion The expression of Cyp gene fragment of human embryo lung cells transformed by Ni2O3 was down-regulated.