Study In The Effect On SUV39H1Gene Targeting SiRNA In KG-1Cell Line

Objective: To study small interfering RNA （siRNA） targeting SUV39H1geneeffect on cell proliferation, apoptosis and histone modulation in KG-1cells line.Methods：（1） The optimal segment targeting SUV39H1gene was designed andtransfected into KG-1cells by Lipofectamine^TM2000. The efficiency of the siRNAwas detected by RT-PCR.（2） Cell growth inhibited by SUV39H1siRNA wasdetermined by MTS. Cell apoptosis was measured by Flow cytometry.（3） Theexpression of Bcl-2, procaspase-9, procaspase-3, P15and C-myc was detected byWestern blot. The expression of histone methylation of H3K9and histone acetylatiomof H3, H3K9, H3K14, H3K27and H4was also detected by Western blot.Results:（1） The efficiency of transfection with SUV39H1siRNA for6hours was（75±2.64）%. The sequence of optimal segment of siRNA was sense5’-CGUGGAUUGUCUCAGG GAATT-3’, antisense5’-UUCCCUGAGACAAUCCACGTG-3’.（2） SUV39H1siRNA upregulated P15and suppressed the proliferation inKG-1cells. The expression of C-myc, Bcl-2, procaspase-9, procaspase-3wassuppressed and cells apoptosis was induced.（3） SUV39H1siRNA downregulatedhistone methylated H3K9and upregulated histone acetylation of H3and H3K9remarkbly. The change of histone acetylation of H4, H3K14and H3K27was not seen.Conclusions:（1） Lipofectamine^TM2000transfected siRNA for SUV39H1geneinto KG-1cells has high efficiency.（2） SUV39H1siRNA inhibites cell growth andinduces cell apoptosis in KG-1cell line. It might be a new therapeutic target in humanleukemia.（3） SUV39H1siRNA downregulates histone methylated H3K9andupregulates histone acetylation of H3and H3K9. It doesn’t affect histone acetylationof H4, H3K14and H3K27. The mechanism of SUV39H1effect on histone acetylationneed to be further studied.（4） SUV39H1siRNA induces the reexpression of P15. Itmight modify histone methylation or acetylation of H3K9in P15gene promoterregion and reactivate the expression.