摘要
目的研究氯化镉致人细胞和整体动物DNA损伤作用和对原癌基因等相关蛋白表达的影响。方法雄性Wistar大鼠,体重约150g,按每组8只分为1个对照组和2个染毒剂量组,以生理盐水配制氯化镉溶液经皮下注射进行染毒,剂量分别为5和20μmol/kg,对照组注射生理盐水。用集落形成实验和四唑盐比色法(MTF)测定氯化镉的细胞毒性,用彗星实验检测氯化镉对DNA的损伤,采用流式细胞术测定细胞周期的变化,用免疫印迹和X-Gal染色检测相关蛋白的表达改变。结果镉能明显抑制细胞增殖,对人成纤维和整体动物细胞DNA有明显的损伤作用,成纤维细胞彗星细胞率由对照组的6．1%增加到200μM剂量组的23．2%,差异有统计学意义(P＜0．01)。雄性大鼠各个脏器在镉染毒后彗星细胞的频率均随剂量的增高而增加,其中肾和腹侧前列腺的DNA损伤同对照组比较差异有统计学意义(P＜0．05),镉能进一步引起细胞周期阻滞。原癌基因c-myc、c-Jun和老化标记蛋白β-Gal均被氯化镉诱导增加。结论氯化镉能致DNA损伤并进一步引起细胞周期停滞,导致细胞老化、死亡。氯化镉诱导细胞的DNA损伤和原癌基因表达的增加也可能是镉致癌的重要原因。
Objective To explore the DNA damage and the expression of oncogenic protein induced by cadmium in vitro（human cells） and in vivo in rats. Methods The colony formation assay and the MTF assay were employed to determine the cytotoxicity of cadmium. The DNA damage and the cell cycle were measured by the cornet assay and the flow cytometry, respectively. The western bolt and the X-Gal staining were also used to determine the change of oncogenic protein and the senescent marker. Results The cadmium inhibited the proliferation of cells and induced DNA damage significantly not only in human cultured cells but also in vivo animal cells. The cornet rate increased from 6.1% in the control group to 23.2% in 200μM cadmium treatment group（ P 〈 0.01 ）. The cornet rate increased in all organs of male rats with the increase of dosage, and there were significant difference between treatmnt the groups and the control group in kidney and ventral prostate （ P 〈 0.05）. Furthermore, the cadmium blocked the cell cycle progression. At the same time, the expression of c-myc, c-Jun and β-Gal were increased by cadmium. Conclusion The cadmium could induce DNA damage and block the cell cycle, and further cause senescence, and death. However, the cadmium induced the DNA damage and the oncogenic protein expression may be the important factors to cause cancer.
出处
《中华劳动卫生职业病杂志》
CAS
CSCD
北大核心
2006年第10期587-590,共4页
Chinese Journal of Industrial Hygiene and Occupational Diseases
基金
国家科委基金(2002CB512905)
