缺锌对经 MNNG 诱导的 HEEC 氧化应激和甲基化的影响.

Objective To explore the effect of zinc deficiency on oxidative stress and methylation of human normal esophageal epithelial cells (HEEC) induced by N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) .Methods The cells were divided into the normal control group, the zinc-rich group, the positive control group and the zinc-deficient group, and intervened for 12,24 and 48 hours respectively. The levels of malondialdehyde (MDA),superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),methylation status of O6-methylguanine-DNA methyltransferase (MGMT) and MLH1 genes and expression level of MGMT protein were compared in each group. Results The median inhibitory concentration of TPEN on HEEC was 1.0 μmol/L. The levels of MDA and GSH-Px in the four groups at different time points were significantly different (P<0.05) .The level of SOD in the four groups at 12 hours was significantly different (P<0.05) .MGMT and MLH1 genes in the four groups showed partial methylation. The expression level of MGMT protein in the four groups was significantly different at 24 hours (P<0.05),but there was no significant difference at 12 and 48 hours (P>0.05) .Conclusion Zinc deficiency can lead to oxidative stress, methylation of MGMT and MLH1 genes and abnormal expression of MGMT protein in HEEC induced by MNNG. [ABSTRACT FROM AUTHOR]