[A study of the substitution effect of hOGG1 and hMTH1 in oxidative DNA damage with gene-deficient cell strains].
OBJECTIVE
To investigate the potential substitution effect of hOGG1 and hMTH1 on oxidative DNA damage, based on gene-deficient cell strains models.


METHODS
hOGG1 and hMTH1 gene deficient cell strains models were established by Human embryonic lung fibroblasts (HFL) cells. After HFL cells being exposed to 100 µmol/L H₂O₂ for 12 h, HPLC-EC detecting technique and RT-PCR method were adopted to analyze the genetic expression level of 8-oxo-dG (7, 8-dihydro-8-oxoguanine).


RESULTS
The gene-deficient cell strains models of hOGG1 and hMTH1 were obtained by infecting target cells with high titer of lentivirus. The mRNA expression level of hOGG1 was 0.09 ± 0.02, 91% lower than it in normal HFL cells, which was 1.00 ± 0.04. As the same, the mRNA expression level of hMTH1 (0.41 ± 0.04) also decreased by 60% compared with it in normal HFL cells (1.02 ± 0.06). After induced by 100 µmol/L H₂O₂ for 12 h, the genetic expression level of hMTH1 in hOGG1 gene-deficient cells (1.26 ± 0.18) increased 25% compared with it in control group (1.01 ± 0.07). Meanwhile, the genetic expression level of hOGG1 in hMTH1 gene-deficient cells (1.54 ± 0.25) also increased by 52%. The DNA 8-oxo-dG levels in hOGG1 gene-deficient cells (2.48 ± 0.54) was 3.1 times compared with it in the control group (0.80 ± 0.16), the difference showed statistical significance (P < 0.01). Whereas the 8-oxo-dG levels in hMTH1 gene-deficient cells (1.84 ± 0.46) was 2.3 times of it in the control group, the difference also showed statistical significance (P < 0.01).


CONCLUSIONS
Based on gene-deficient HFL cells models, a synergetic substitution effect on DNA damage and repair activity by both hOGG1 and hMTH1 were firstly discovered when induced by oxidation. The substitution effect of hOGG1 were stronger than that of hMTH1.
Key Laboratory of Molecular Biology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China. Email: keyke@163.net.
Yuebin
Y
Ke
Key Laboratory of Molecular Biology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
Shuang
S
Wu
Key Laboratory of Molecular Biology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
Juan
J
Huang
Key Laboratory of Molecular Biology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
Jianhui
J
Yuan
Key Laboratory of Molecular Biology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
Pingjian
P
Deng
Key Laboratory of Molecular Biology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
Jinquan
J
Cheng
D002460:Cell Line; D004249:DNA Damage; D045647:DNA Glycosylases / Q000235:genetics*; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D018384:Oxidative Stress / Q000235:genetics*; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics*
D010744:Phosphoric Monoester Hydrolases; D045647:DNA Glycosylases; C479058:oxoguanine glycosylase 1, human; C078207:8-oxodGTPase; D045643:DNA Repair Enzymes