Study In The Effect On EZH2Gene Targeting SiRNA In HL-60Cell Line

Objective: To study small interfering RNA (siRNA) targeting EZH2gene effect oncell proliferation, apoptosis and histone H3K27methylation and histone H3acetylation modulation in HL-60cells line.Methods:（1）Three siRNA segments targeting EZH2gene were designed andtransfected into HL-60cells by LipofectamineTM2000. The optimal segment wasscreened by RT-PCR.（2）Cell growth inhibited by EZH2siRNA was determined byWST-1. Cell apoptosis was measured by Flow cytometry.（3）The expression ofprocaspase-3, procaspase-9, Bcl-2, and Bax was detected by Western blot. The levelsof histone H3lysine27dimethylation and trimethylation and histone acetylatiom ofH3were evaluated by Western blot.Results:（1）The efficiency of transfection with EZH2siRNA for6hours was (82±2.97)%. The sequence of optimal segment of EZH2siRNA was sense5’-GAGGGAAAGUGUAUGAUAATT-3’， antisense5’-UUAUCAUACACUUUCCCUCTT-3’。（2）EZH2siRNA suppressed the proliferation of HL-60cells.（3）EZH2siRNA downregulates the expression of procaspase-3, procaspase-9, Bcl-2andupregulates the expression of Bax and induced cells apoptosis.（4） EZH2siRNAsuppressed the protein and mRNA of EZH2in HL-60cells. The levels of histone H3lysine27dimethylation and trimethylation was down regulated and histoneacetylatiom of H3was up regulated.Conclusions:(1) siRNA for EZH2gene transfected into HL-60cells byLipofectamineTM2000has high efficiency.（2）EZH2siRNA inhibits cell growth andinduces cell apoptosis in HL-60cell line. It might be a new therapeutic target inhuman leukemia.(3) EZH2siRNA downregulates the levels of histone H3lysine27dimethylation and trimethylation and upregulates histone acetylation of H3. Themechanism of EZH2effect on histone acetylation need to be further studied. RNAitechnology is expected to become a new tool for targeted gene therapy of acute leukemia, and EZH2might be one of the targets of gene therapy for leukemia.