ObjectiveTo study whether miR-15a and miR-16-1 can enhance the sensitivity of Raji cells to cytarabine (Ara-C).MethodsMiR-15a and miR-16-1 oligonucleotides were transfected into Raji cells with LipofectamineTM 2000,and then the cells were treated with Ara-C.The IC50 values of Ara-C was detected by CCK8 assay.The growth of Raji cells was measured by trypan blue dye exclusion method.The apoptotic cells were observed by Hoechst dyeing; AnnexinⅤ/PI double dyeing and glow cytometry(FCM) were used to examine the cell apoptotic rate.ResultsAfter transfection of miR-15a or miR-16-1 into Raji cells,the IC50 values of Ara-C were 10.41 and 10.86,respectively,which were significantly lower than that of the untransfected group(15.43)and scrambled oligonucleotides （SODN）transfection group（14.92,P<0.05）.Trypan blue dye exclusion assay showed that miR-15a/miR-16-1 transfection group had obviously decreased the cell growth compared to miR-15a,miR-16-1 group,untransfected group and SODN transfected group; Hoechst dyeing demonstrated plenty of apoptotic cells.AnnexinⅤ/PI double dyeing assays by FCM indicated that the cell apoptotic rates in earlier period and late period were 20.93% and 25.27% in the miR-15a+Ara-C group,and 20.69% and 23.13% in the miR-16-1+Ara-C group,which were obviously higher than those in miR-15a group (6.99%,10.08%),miR-16-1 group(4.73%,10.64%),Ara-C group(10.88%,11.83%) and control group (14.39%,11.93%).ConclusionMiR-15a and miR-16-1 oligonucleotides can enhance the sensitivity of Raji cells to Ara-C.