Study On P15～(INK4B) Gene Methylation In Myelodysplastic Syndromes And Demethylating Activity Of Decitabine And Arsenic Trioxide

Objective To detect the methylation status of p15^INK4B gene in the patients with myelodysplastic syndromes (MDS), and investigate the effects of decitabine and arsenic trioxide (As₂O₃) to demethylate the cultured cells from MDS patient.Methods The methylation status of p15 ^INK4B gene of the mononuclear cells obtained from the MDS patient's bone marrow aspiration were analyzed with restrictive endonucleases combined with PCR technique. β-globin gene was set as an internal reference of the specific amplified band to confirm the degree of methylation. The cultured peripheral blood mononuclear cells from a MDS patient, in whom the hypermethylation status of p15 ^INK4B gene had been identified, was chosen as the experimental target cells. The MDS cells was cultured with decitabine and As₂O₃ in vitro to explore the change of methylation degree.Results There was no p15 ^INK4Bgene methylation detected in the low-risk group MDS patients, but this gene hypermethylation were detected in 80% patients of high-risk group and 66.6% patients in MDS progressing to AML group. After exposed to decitabine and AS2O3. the methylation degree of thecultured cells fell down from 19.73% to 8.82-10.06%. No significant difference in demethylating effect was found between these two agents. Conclusion Our study has showed the results that pi 5 INK4B gene hypermethylation is closely associated with MDS pathogenesis, and the status of gene hypermethylation occurs more frequently with the progression of MDS. Decitabine and AS2O3 have obvious demethylating activity to the cultured cells from a MDS patient, and no significant difference in demethylating effect was found between the two agents.