Study of 5-Aza-CdR induced demethylation of RAR-βGene and its expression in lung cancer cell line SPC-A-1

LI Qi; LIU Li-min; YANG Yu-mei; XIE Yan-li; LI Yu-lei

Abstract：Objective To observe effects of 5-Aza-CdR on RAR-βgene methylation status changes in lung adenocarcinoma cells SPC-A-1, and to investigate the regulatory mechanism of 5-Aza-CdR in different concentra-tions for defective expression of RAR-βgene.Methods The human lung adenocarcinoma SPC-A-1 cells were di-vided into four groups:Group A (control group) and Group B, C, D (dosing groups).Differences in RAR-βgene methylation status, mRNA expression and protein expression among the four groups were assessed by methylation-specific PCR ( MSP) , RT-PCR, and Western blot, respectively.Furthermore, differences in cell cycle and apoptosis rate among the four groups were detected by Flow cytometry.Results RAR-βgene methylation was observed in Group A, while demethylation of RAR-βgene was observed in the other 3 groups.After 5-Aza-CdR treatment, the expression levels of RAR-βin SPC-A-1 cells were significantly enhanced ( P<0.01 ) .Apoptosis rates in 5-Aza-CdR treatment groups were significantly increased compared with Group A ( P<0.01 ) .Conclusion RAR-βgene in lung cancer is defective expressed due to its methylation, which could be reversed by 5-Aza-CdR via its demethylation effect.5-Aza-CdR promotes apoptosis and inhibits cell proliferation in lung cancer, and thus plays a role in cancer treatment.