OBJECTIVETo explore the role of microRNA-124(miR-124) in the pathogenesis of myelodysplastic syndromes(MDS) through detecting the expression level of miR-124 in bone marrow mononuclear cells(MNC) of MDS patients before and after demethylating therapy with decitabine.

METHODSThe expression levels of miR-124 in the MNC of 35 MDS patients and 10 healthy donors were detected with stem-loop quantitative real time polymerase chain reaction assay.

RESULTSThe expression level of miR-124 was lower in MDS patients than that in healthy donors. The difference was not statistically significant between patients with low-risk MDS subtypes (RA and RCMD) and control, but statistically significant between patients with high-risk MDS subtypes (RAEB1, RAEB2 and CMML) and control. This study also proved that expression of miR-124 was reactivated in 7 out of 18 MDS patients after treatment with low dose decitabine.

CONCLUSIONThe hypermethylation and silencing of miR-124 may be an important factor in the clonal transformation of MDS cells.