RESUMO
<p><b>OBJECTIVE</b>To study the effect of small interfering RNA(siRNA) targeting JARID1B gene on the proliferation and apoptosis in HL-60 acute promyelocytic leukemia cell line, and to explore its mechanisms.</p><p><b>METHODS</b>The JARID1B siRNA was transfected into HL-60 cells using Lipofectamine(TM) 2000(Lipo) vector. The proliferation inhibition by siRNA targeting JARID1B was detected by MTT, cells apoptosis by flow cytometry, the mRNA expression of JARID1B by RT-PCR, the protein expression of JARID1B, Bcl-2, procaspase-9, procaspase-3, c-myc and P27 and histone methylated H3K4 by Western blot.</p><p><b>RESULTS</b>siRNA targeting JARID1B upregulated histone methylated H3K4 level, inhibited the proliferation of HL-60 cells, and induced the cells apoptosis. After transfection of siRNA targeting JARID1B at 0, 30, 60, 120 nmmol/L for 24 hours, the apoptotic rate were (11.0 ± 3.6)%, (35.2 ± 5.1)%, (52.7 ± 3.8)%, and (62.0 ± 5.7)% respectively (F = 70.27, P < 0.01). The protein expression of P27 was upregulated, and Bcl-2, procaspase-9, procaspase-3, c-myc was down regulated.</p><p><b>CONCLUSIONS</b>JARID1B siRNA upregulates histone methylated H3K4. It reduces HL-60 cells proliferation and apoptosis by up regulating the p27 expression and down regulating the Bcl-2, procaspase-9, procaspase-3, c-myc expression. It might be a new therapeutic targeting for human leukemia.</p>