[Establishment and characterization of the lung cancer A549 cell stains with down-regulated expressed HOGG1 genes]

To establish lung cancer A549 cell strains with down-regulated expressed HOGG1 genes and study its biological characteristics.

The eukaryotic expression vectors with genes of hammerhead ribozyme targeting human 8-oxoguanine DNA glycosylase 1 (HOGG1) mRNA were transfected into A549 cells by liposmes, and then were screened by G418 till stable cell strains were constructed. The positive recombinants were identified by RT-PCR to amplify NEO genes. The efficacy of inhibition was tested by RT-PCR. Furthermore, morphology, survival curves, cell cycle, cloning efficiency grow in the soft agar and the activity of superoxide dismutase (SOD) were investigated.

The HOGG1-down-regulated expressed A549 cell strains were obtained after G418 selection and NEO genes identification. The mRNA expression level of HOGG1 genes in the down-regulated expressed cells named A549-R were decreased 61.5% than in the untransfected cells A549 (P < 0.05). There was no significant difference between A549-R cells and A549 cells in morphology, the population doubling time and cell cycle. The numbers of clones in the soft agar of A549-R cells was decreased nearly to 50% than of A549 cells (P < 0.05), but the activity of SOD was increased obviously (P < 0.05).

The lung cancer A549 cell strains with down-regulated expressed HOGG1 genes by silencing and incision of ribozyme were successfully established. Its biological characteristics have no significant changes in most of indexes.