肝肿瘤发生中过氧亚硝酸阴离子标志物作用

目的比较过氧亚硝酸阴离子（ONOO^-）对正常人胚肝细胞株L-02和肝母细胞瘤细胞株HepG2 DNA损伤和细胞毒性差异，探索ONOO^-在肝肿瘤发生中的作用及可能标志物。方法0．01，0．05，0．1mmol／L ONOO^-作用细胞后，检测ONOO^-对2株肝细胞的细胞生存率，超氧化物歧化酶（SOD）、谷胱甘肽（GSH）、过氧化氢酶（CAT）、丙二醛（MDA）含量变化，DNA损伤，生长抑制DNA损伤基因（GADD）表达的影响差异。结果ONOO^-使2种肝细胞的生存率下降、SOD含量降低（P〈0．05）和CAT、GSH的显著变化，显著升高MDA的含量；DNA损伤程度和GADD45、GADD153基因表达水平在2株肝细胞均随着剂量的增加显著升高。2种肝细胞相比，各浓度组L-02细胞损伤程度大于HepG2细胞，但只有GADD基因表达水平差异有统计学意义（P〈0．05）。结论ONOO^-对正常肝细胞和肝癌细胞均显示细胞毒性作用，引起DNA损伤，诱导GADD表达。GADD基因表达水平在不同肝细胞中差异有统计学意义，可能是ONOO^-细胞损伤效应的标志物。

Effects and biomarkers of peroxynitrite on development of liver tumor

Objective To compare the DNA damages and cytotoxicit effect of peroxynitrite(ONOO~-)to human embryo liver L-02 cells and human hepatic tumor HepG2 cells. Methods Two liver cells were exposed to different concentration peroxynitrite(0.01,0.05,0.1mmol/L).Survival rate,level of superoxide dismutase(SOD),glutamylcysteinylglycine(GSH),catalase(CAT),Malonyldiadehyde(MDA),DNA damage and the expression level of Growth arrest and DNA damage-inducible genes(GADD)were measured. Results After exposed to peroxynitrite,L-02 and HepG2 cells survival rate decreased from 87.55%,90.34% to 19.21%,21.59% varying concentration ranging 0.01mmol/L to 0.2mmol/L,respectively.0.01mmol/L to 0.2mmol/L,respectively.Peroxynitrite caused GSH,CAT level significantly change,decreased SOD level and increased MED level in L-02 and HepG2 cells(P<0.05).DNA damage and GADD expression level increased as peroxynitrite concentration increased in both two cell lines(P<0.05).All these damages were more serious in L-02 in every concentration level than that of HepG2,but only the expression level of GADD were significant difference between L-02 and HepG2 cells. Conclusion Peroxynitrite had cytotoxicity effect and significant difference was observed in two cells.GADD expression level maybe one of the biomarkers of NONN~-damage effects.