Effects of demethylation on the growth of human gastric carcinoma cell lines and the expression of xaf1 gene

AIM: To observe the effects of the demethylating agent,5-Aza-2′-deoxyctidine(5-Aza-CdR),on the proliferation,cell cycle,apoptosis and xaf1 mRNA expression of stomach cancer BGC823 cells.METHODS: The proliferation of BGC823 cells treated by different concentrations of 5-Aza-CdR was detected by MTT assay.Assessment of cell cycle and apoptosis were performed by flow cytometry(FCM);the change of xaf1 mRNA expression was semi-quantified by RT-PCR before and after 5-Aza-CdR treatment.RESULTS: The growth inhibitory effects on BGC823 cells were observed in a dose-dependent manner after exposure to 5-Aza-CdR at different concentrations(1×103,5×103,10×103 nmol/L) for different time.FCM analysis showed that the apoptosis rates in BGC823 cells [(4.53±0.21)%,(8.11±1.01)%,(11.56±0.86)%] increased significantly after exposure to 5-Aza-CdR for 72 h as compared with the control group [(0.51±0.01)%,P0.05].No expression of xaf1 gene in BGC823 cells was observed,but it was expressed after 5-Aza-CdR treatment(5×103,10×103 nmol/L).CONCLUSION: 5-Aza-CdR can inhibit the proliferation of BGC823 cells through blocking cell cycles and inducing cell apoptosis.It can also restore xaf1 gene transcription silenced by demethylation.