[Oxidative damage effects of A549 and A549-R cells induced by mainstream smoke]

To explore the effects of oxidative damage induced by mainstream smoke (MS) on A549 and A549-R cells of hOGG1 deficient cell.

A549 cells and A549-R cells with down-regulated hOGG1 gene were treated at the concentrations of MS for 2h. The cellular sensitivities and DNA damages were measured by MTT assay and comet assay, respectively. The contents of ROS and 8-OHdG in both cells were examined by fluorescence method and HPLC-ECD.

The cell viabilities decreased with increases of concentration of MS. The IC50 of hOGG1 deficient A549-R cell was more lower than that in A549 cell (P < 0.05). With dose increases of MS, the contents of ROS increased in both cell lines. When MS was more than or equal to 1.25 No. of cigarette/L, the contents of ROS in A549-R cells were much higher than those in A549 cells. The comet assay indicated that DNA damages of A549-R cells were more higher than those in A549 cells, and comet rate, tail length and OTM in A549-R cells were more higher in comparison with A549 cells (P < 0.05) at the levers of all concentrations. Furthermore, the levels of 8-OHdG in A549-R cells were higher than those of A549 cells at the doses of 2.5 and 5 No. of cigarette/L (P < 0.05).

Mainstream smoke could induce oxidative damage in A549 and A549-R cells and hOGG1 deficiency cell could increase sensitivity to MS.